TOP242-250 TOPSwitch®-GX Family Extended Power, Design Flexible, EcoSmart,® Integrated Off-line Switcher Product Highlights + AC DC Lower System Cost, High Design Flexibility IN OUT - • Extended power range for higher power applications • No heatsink required up to 34 W using P/G packages • Features eliminate or reduce cost of external components D L • Fully integrated soft-start for minimum stress/overshoot CONTROL • Externally programmable accurate current limit TOPSwitch-GX C • Wider duty cycle for more power, smaller input capacitor • Separate line sense and current limit pins on Y/R/F packages S X F • Line under-voltage (UV) detection: no turn off glitches • Line overvoltage (OV) shutdown extends line surge limit PI-2632-060200 • Line feed-forward with maximum duty cycle (DC ) MAX reduction rejects line ripple and limits DC at high line Figure 1. Typical Flyback Application. MAX • Frequency jittering reduces EMI and EMI filtering costs • Regulates to zero load without dummy loading OUTPUT POWER TABLE • 132 kHz frequency reduces transformer/power supply size 230 VAC ±15%4 85-265 VAC • Half frequency option in Y/R/F packages for video applications • Hysteretic thermal shutdown for automatic fault recovery PRODUCT3 Open Open Adapter1 Adapter1 • Large thermal hysteresis prevents PC board overheating Frame2 Frame2 TOP242 P or G 9 W 15 W 6.5 W 10 W EcoSmart – Energy Efficient TOP242 R 15 W 22 W 11 W 14 W • Extremely low consumption in remote off mode TOP242 Y or F 10 W 22 W 7 W 14 W (80 mW at 110 VAC, 160 mW at 230 VAC) TOP243 P or G 13 W 25 W 9 W 15 W • Frequency lowered with load for high standby efficiency TOP243 R 29 W 45 W 17 W 23 W • Allows shutdown/wake-up via LAN/input port TOP243 Y or F 20 W 45 W 15 W 30 W TOP244 P or G 16 W 28 W 11 W 20 W Description TOP244 R 34 W 50 W 20 W 28 W TOP244 Y or F 30 W 65 W 20 W 45 W TOPSwitch-GX uses the same proven topology as TOPSwitch, TOP245 P or G 19 W 30 W 13 W 22 W cost effectively integrating the high voltage power MOSFET, TOP245 R 37 W 57 W 23 W 33 W PWM control, fault protection and other control circuitry onto TOP245 Y or F 40 W 85 W 26 W 60 W a single CMOS chip. Many new functions are integrated to TOP246 P or G 21 W 34 W 15 W 26 W reduce system cost and improve design flexibility, performance TOP246 R 40 W 64 W 26 W 38 W and energy efficiency. TOP246 Y or F 60 W 125 W 40 W 90 W TOP247 R 42 W 70 W 28 W 43 W Depending on package type, either 1 or 3 additional pins over TOP247 Y or F 85 W 165 W 55 W 125 W the TOPSwitch standard DRAIN, SOURCE and CONTROL terminals allow the following functions: line sensing (OV/UV, TOP248 R 43 W 75 W 30 W 48 W line feed-forward/DC reduction), accurate externally set TOP248 Y or F 105 W 205 W 70 W 155 W MAX current limit, remote ON/OFF, synchronization to an external TOP249 R 44 W 79 W 31 W 53 W lower frequency, and frequency selection (132 kHz/66 kHz). TOP249 Y or F 120 W 250 W 80 W 180 W TOP250 R 45 W 82 W 32 W 55 W All package types provide the following transparent features: TOP250 Y or F 135 W 290 W 90 W 210 W Soft-start, 132 kHz switching frequency (automatically reduced at light load), frequency jittering for lower EMI, wider DC , Table 1. Notes: 1. Typical continuous power in a non-ventilated enclosed MAX adapter measured at 50 °C ambient. 2. Maximum practical continuous hysteretic thermal shutdown, and larger creepage packages. In power in an open frame design at 50 °C ambient. See Key Applications addition, all critical parameters (i.e. current limit, frequency, for detailed conditions. 3. For lead-free package options, see Part PWM gain) have tighter temperature and absolute tolerances Ordering Information. 4. 230 VAC or 100/115 VAC with doubler. to simplify design and optimize system cost. November 2005

TOP242-250 Section List Functional Block Diagram ....................................................................................................................................... 3 Pin Functional Description ...................................................................................................................................... 4 TOPSwitch-GX Family Functional Description .......................................................................................................5 CONTROL (C) Pin Operation ..................................................................................................................................6 Oscillator and Switching Frequency ........................................................................................................................6 Pulse Width Modulator and Maximum Duty Cycle ..................................................................................................7 Light Load Frequency Reduction ............................................................................................................................7 Error Amplifier .........................................................................................................................................................7 On-Chip Current Limit with External Programmability ............................................................................................7 Line Under-Voltage Detection (UV) .........................................................................................................................8 Line Overvoltage Shutdown (OV) ...........................................................................................................................8 Line Feed-Forward with DC Reduction ..............................................................................................................8 MAX Remote ON/OFF and Synchronization ...................................................................................................................9 Soft-Start .................................................................................................................................................................9 Shutdown/Auto-Restart ...........................................................................................................................................9 Hysteretic Over-Temperature Protection .................................................................................................................9 Bandgap Reference ..............................................................................................................................................10 High-Voltage Bias Current Source ........................................................................................................................10 Using Feature Pins ...................................................................................................................................................10 FREQUENCY (F) Pin Operation ...........................................................................................................................10 LINE-SENSE (L) Pin Operation ............................................................................................................................10 EXTERNAL CURRENT LIMIT (X) Pin Operation ..................................................................................................11 MULTI-FUNCTION (M) Pin Operation ..................................................................................................................11 Typical Uses of FREQUENCY (F) Pin ......................................................................................................................14 Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins ......................................................15 Typical Uses of MULTI-FUNCTION (M) Pin ...........................................................................................................17 Application Examples ..............................................................................................................................................20 A High Efficiency, 30 W, Universal Input Power Supply ........................................................................................20 A High Efficiency, Enclosed, 70 W, Universal Adapter Supply ..............................................................................20 A High Efficiency, 250 W, 250-380 VDC Input Power Supply ...............................................................................22 Multiple Output, 60 W, 185-265 VAC Input Power Supply ....................................................................................23 Processor Controlled Supply Turn On/Off .............................................................................................................24 Key Application Considerations .............................................................................................................................26 TOPSwitch-II vs. TOPSwitch-GX ..........................................................................................................................26 TOPSwitch-FX vs. TOPSwitch-GX .......................................................................................................................28 TOPSwitch-GX Design Considerations ...............................................................................................................28 TOPSwitch-GX Layout Considerations .................................................................................................................30 Quick Design Checklist .........................................................................................................................................32 Design Tools .........................................................................................................................................................32 Product Specifications and Test Conditions .........................................................................................................33 Typical Performance Characteristics ....................................................................................................................40 Part Ordering Information .......................................................................................................................................46 Package Outlines .....................................................................................................................................................47 O 2 11/05

TOP242-250 VC 0 CONTROL (C) DRAIN (D) ZC INTERNAL 1 SUPPLY SHUNT REGULATOR/ ERROR AMPLIFIER + - 54..88 VV - SOFT START + 5.8 V INTERNAL UV IFB COMPARATOR VI (LIMIT) CURRENT LIMIT SOFT ADJUST START - ÷ 8 ON/OFF + VBG + VT SHUTDOWN/ AUTO-RESTART CURRENT LIMIT COMPARATOR EXTERNAL CURRENT LIMIT (X) HYSTERETIC STOP LOGIC THERMAL LINE-SENSE (L) 1 V SHUTDOWN CONTROLLED VBG STOP SOFT- GATTUER DNR-OIVNER OV/UV START LINE DMAX SENSE DCMAX DCMAX CLOCK FREQUENCY (F) HFRAELQF . SAW +- RS Q BLLEEAADNDGKINEINGG OSCILLATOR WITH JITTER PWM COMPARATOR LIGHT LOAD RE FRREEDQUUCETINOCNY SOURCE (S) PI-2639-060600 Figure 2a. Functional Block Diagram (Y, R or F Package). VC 0 CONTROL (C) DRAIN (D) ZC INTERNAL 1 SUPPLY SHUNT REGULATOR/ ERROR AMPLIFIER + - 54..88 VV - SOFT START + 5.8 V INTERNAL UV IFB COMPARATOR VI (LIMIT) CURRENT LIMIT SOFT ADJUST START ÷ 8 - ON/OFF + SHUTDOWN/ AUTO-RESTART CURRENT LIMIT VBG + VT COMPARATOR MULTI- STOP LOGIC HYSTERETIC FUNCTION (M) THERMAL SHUTDOWN VBG CONTROLLED TURN-ON STOP SOFT- GATE DRIVER OV/UV START LINE DMAX SENSE DCMAX DCMAX CLOCK S Q SAW - LEADING + R BLEADNGKEING OSCILLATOR WITH JITTER PWM COMPARATOR LIGHT LOAD RE FRREEDQUUCETINOCNY SOURCE (S) PI-2641-061200 Figure 2b. Functional Block Diagram (P or G Package). O 11/05 3

TOP242-250 Pin Functional Description FREQUENCY (F) Pin: (Y, R or F package only) Input pin for selecting switching frequency: 132 kHz if DRAIN (D) Pin: connected to SOURCE pin and 66 kHz if connected to High voltage power MOSFET drain output. The internal CONTROL pin. The switching frequency is internally set for start-up bias current is drawn from this pin through a switched fixed 132 kHz operation in P and G packages. high-voltage current source. Internal current limit sense point for drain current. SOURCE (S) Pin: Output MOSFET source connection for high voltage power CONTROL (C) Pin: return. Primary side control circuit common and reference point. Error amplifier and feedback current input pin for duty cycle 3 control. Internal shunt regulator connection to provide internal 20 bias current during normal operation. It is also used as the + VUV = IUV x RLS 092 VOV = IOV x RLS 29- connection point for the supply bypass and auto-restart/ 6 2 compensation capacitor. R 2 MΩ For RLS = 2 MΩ PI- LS V = 100 VDC UV V = 450 VDC OV LINE-SENSE (L) Pin: (Y, R or F package only) DC DC @100 VDC = 78% Input pin for OV, UV, line feed forward with DC reduction, Input D L MAX MAX DCMAX@375 VDC = 38% remote ON/OFF and synchronization. A connection to SOURCE Voltage CONTROL C pin disables all functions on this pin. For RIL = 12 kΩ I = 69% S X LIMIT EXTERNAL CURRENT LIMIT (X) Pin: (Y, R or F package See Figure 54b for R IL other resistor values only) - 12 kΩ (R ) to select different IL Input pin for external current limit adjustment, remote I values LIMIT ON/OFF, and synchronization. A connection to SOURCE pin disables all functions on this pin. Figure 4. Y/R/F Pkg Line Sense and Externally Set Current Limit. MULTI-FUNCTION (M) Pin: (P or G package only) + This pin combines the functions of the LINE-SENSE (L) and V = I x R UV UV LS EXTERNAL CURRENT LIMIT (X) pins of the Y package V =I xR OV OV LS into one pin. Input pin for OV, UV, line feed forward with DCMAX reduction, external current limit adjustment, remote RLS 2 MΩ F oVr URVL =S 1=0 20 MVΩDC ON/OFF and synchronization. A connection to SOURCE pin DC V =450 VDC OV Input disables all functions on this pin and makes TOPSwitch-GX Voltage DC @100 VDC = 78% operate in simple three terminal mode (like TOPSwitch-II). MAX D M DC @375 VDC = 38% MAX CONTROL C Y Package (TO-220-7C) - S Tab Internally 7 D Connected to 5 F PI-2509-040501 SOURCE Pin 4 S 3 X Figure 5. P/G Package Line Sense. 2 L 1 C R Package (TO-263-7C) + F Package (TO-262-7C) For RIL = 12 kΩ I = 69% P Package (DIP-8B) LIMIT G Package (SMD-8B) For RIL = 25 kΩ I = 43% LIMIT M 1 8 S DC See Figures 54b, 55b Input and 56b for other resistor S 2 7 S Voltage values (R ) to select D M IL different I values. S 3 LIMIT CONTROL RIL C C 4 5 D 123 4 5 7 CLXSF D PI-2724-010802 - S Figure 3. Pin Configuration (top view). PI-2517-022604 Figure 6. P/G Package Externally Set Current Limit. O 4 11/05

TOP242-250 TOPSwitch-GX Family Functional Auto-restart I I Description CD1 B I = 125 µA L Like TOPSwitch, TOPSwitch-GX is an integrated switched 132 mode power supply chip that converts a current at the control z) ipnopwuet rt oM a OduStFyE cTy.c l eD aut rtihneg o npoenrm daral ino poeurtaptuiot no ft hae h idguht yv oclytacglee y (kH IL = 190 µA IL < IL(DC) c of the power MOSFET decreases linearly with increasing n e CONTROL pin current as shown in Figure 7. qu e r F 30 In addition to the three terminal TOPSwitch features, such as the high voltage start-up, the cycle-by-cycle current limiting, loop compensation circuitry, auto-restart, thermal shutdown, I (mA) C the TOPSwitch-GX incorporates many additional functions that reduce system cost, increase power supply performance and design flexibility. A patented high voltage CMOS technology Auto-restart allows both the high voltage power MOSFET and all the low ICD1 IB voltage control circuitry to be cost effectively integrated onto a single monolithic chip. 78 Slope = PWM Gain %) Three terminals, FREQUENCY, LINE-SENSE, and e ( EpaXcTkaEgReN) oAr Lo nCe UteRrmRiEnNalT M LUILMTIIT-F U(aNvCaiTlaIbOleN i(nav Yai,l aRbl eo irn FP Cycl 38 IL = 125 µA y or G package) have been added to implement some of the new ut I < I D L L(DC) functions. These terminals can be connected to the SOURCE I = 190 µA pin to operate the TOPSwitch-GX in a TOPSwitch-like three 10 L terminal mode. However, even in this three terminal mode, the TOPSwitch-GX offers many new transparent features that do TOP242-5 1.6 2.0 5.2 6.0 TOP246-9 2.2 2.6 5.8 6.6 not require any external components: TOP250 2.4 2.7 I (mA) 6.5 7.3 C Note: For P and G packages I is replaced with I . 1. A fully integrated 10 ms soft-start limits peak currents L M and voltages during start-up and dramatically reduces or PI-2633-011502 eliminates output overshoot in most applications. Figure 7. Relationship of Duty Cycle and Frequency to CONTROL 2. DC of 78% allows smaller input storage capacitor, lower MAX Pin Current. input voltage requirement and/or higher power capability. 3. Frequency reduction at light loads lowers the switching The pin can also be used as a remote ON/OFF and a losses and maintains good cross regulation in multiple output synchronization input. supplies. 4. Higher switching frequency of 132 kHz reduces the The EXTERNAL CURRENT LIMIT (X) pin is usually used transformer size with no noticeable impact on EMI. to reduce the current limit externally to a value close to the 5. Frequency jittering reduces EMI. operating peak current, by connecting the pin to SOURCE 6. Hysteretic over-temperature shutdown ensures automatic recovery from thermal fault. Large hysteresis prevents through a resistor. This pin can also be used as a remote circuit board overheating. ON/OFF and a synchronization input in both modes. See 7. Packages with omitted pins and lead forming provide large Table 2 and Figure 11. drain creepage distance. 8. Tighter absolute tolerances and smaller temperature For the P or G packages the LINE-SENSE and EXTERNAL variations on switching frequency, current limit and PWM gain. CURRENT LIMIT pin functions are combined on one MULTI- FUNCTION (M) pin. However, some of the functions become The LINE-SENSE (L) pin is usually used for line sensing by mutually exclusive as shown in Table 3. connecting a resistor from this pin to the rectified DC high voltage bus to implement line overvoltage (OV), under-voltage The FREQUENCY (F) pin in the Y, R or F package sets the (UV) and line feed-forward with DC reduction. In this switching frequency to the default value of 132 kHz when MAX mode, the value of the resistor determines the OV/UV thresholds connected to SOURCE pin. A half frequency option of and the DC is reduced linearly starting from a line voltage 66 kHz can be chosen by connecting this pin to CONTROL pin MAX above the under-voltage threshold. See Table 2 and Figure 11. instead. Leaving this pin open is not recommended. O 11/05 5

TOP242-250 CONTROL (C) Pin Operation voltage of 5.8 V, current in excess of the consumption of the The CONTROL pin is a low impedance node that is capable chip is shunted to SOURCE through resistor R as shown in E of receiving a combined supply and feedback current. During Figure 2. This current flowing through R controls the duty cycle E normal operation, a shunt regulator is used to separate the of the power MOSFET to provide closed loop regulation. The feedback signal from the supply current. CONTROL pin voltage shunt regulator has a finite low output impedance Z that sets C V is the supply voltage for the control circuitry including the the gain of the error amplifier when used in a primary feedback C MOSFET gate driver. An external bypass capacitor closely configuration. The dynamic impedance Z of the CONTROL C connected between the CONTROL and SOURCE pins is required pin together with the external CONTROL pin capacitance sets to supply the instantaneous gate drive current. The total amount the dominant pole for the control loop. of capacitance connected to this pin also sets the auto-restart timing as well as control loop compensation. When a fault condition such as an open loop or shorted output prevents the flow of an external current into the CONTROL When rectified DC high voltage is applied to the DRAIN pin, the capacitor on the CONTROL pin discharges towards pin during start-up, the MOSFET is initially off, and the 4.8 V. At 4.8 V, auto-restart is activated which turns the output CONTROL pin capacitor is charged through a switched high MOSFET off and puts the control circuitry in a low current voltage current source connected internally between the DRAIN standby mode. The high-voltage current source turns on and and CONTROL pins. When the CONTROL pin voltage V charges the external capacitance again. A hysteretic internal C reaches approximately 5.8 V, the control circuitry is activated supply under-voltage comparator keeps V within a window C and the soft-start begins. The soft-start circuit gradually of typically 4.8 V to 5.8 V by turning the high-voltage current increases the duty cycle of the MOSFET from zero to the source on and off as shown in Figure 8. The auto-restart maximum value over approximately 10 ms. If no external circuit has a divide-by-eight counter which prevents the output feedback/supply current is fed into the CONTROL pin by the MOSFET from turning on again until eight discharge/charge end of the soft-start, the high voltage current source is turned cycles have elapsed. This is accomplished by enabling the off and the CONTROL pin will start discharging in response output MOSFET only when the divide-by-eight counter reaches to the supply current drawn by the control circuitry. If the full count (S7). The counter effectively limits TOPSwitch-GX power supply is designed properly, and no fault condition power dissipation by reducing the auto-restart duty cycle such as open loop or shorted output exists, the feedback loop to typically 4%. Auto-restart mode continues until output will close, providing external CONTROL pin current, before voltage regulation is again achieved through closure of the the CONTROL pin voltage has had a chance to discharge to feedback loop. the lower threshold voltage of approximately 4.8 V (internal supply under-voltage lockout threshold). When the externally Oscillator and Switching Frequency fed current charges the CONTROL pin to the shunt regulator The internal oscillator linearly charges and discharges an ~~ ~~ V UV V ~~ ~~ ~~ LINE 0 V S7 S0 S1 S2 S6 S7 S0 S1 S2 S6 S7 S0 S1 S2 S6 S7 S7 5.8 V V ~~ ~~ ~~ 4.8 V C 0 V ~~ ~~ V DRAIN ~~ 0 V V OUT 0 V ~~ ~~ ~~ 1 2 3 2 4 Note: S0 through S7 are the output states of the auto-restart counter PI-2545-082299 Figure 8. Typical Waveforms for (1) Power Up (2) Normal Operation (3) Auto-Restart (4) Power Down. O 6 11/05

TOP242-250 iaon stsceairlwnlaattolo orct hsae ptwasc atihvtaeen fpocureml sbe e fwotwri dettehhne m ptowudlosu elv awtoolirtda/ctghue r mreleonvdt eullilsma titoto rl .a ct rcTehha atiest FSrweqitucehnincgy 136 kHz PI-2550-092499 the beginning of each cycle. 128 kHz The nominal switching frequency of 132 kHz was chosen to 4 ms minimize transformer size while keeping the fundamental EMI frequency below 150 kHz. The FREQUENCY pin (available V only in Y, R or F package), when shorted to the CONTROL pin, DRAIN lowers the switching frequency to 66 kHz (half frequency) which may be preferable in some cases such as noise sensitive video Time applications or a high efficiency standby mode. Otherwise, the FREQUENCY pin should be connected to the SOURCE pin Figure 9. Switching Frequency Jitter (Idealized V Waveforms). DRAIN for the default 132 kHz. To further reduce the EMI level, the switching frequency is frequency is also reduced linearly until a minimum frequency jittered (frequency modulated) by approximately ±4 kHz at is reached at a duty cycle of 0% (refer to Figure 7). The 250 Hz (typical) rate as shown in Figure 9. Figure 46 shows minimum frequency is typically 30 kHz and 15 kHz for the typical improvement of EMI measurements with frequency 132 kHz and 66 kHz operation, respectively. jitter. This feature allows a power supply to operate at lower Pulse Width Modulator and Maximum Duty Cycle frequency at light loads thus lowering the switching losses The pulse width modulator implements voltage mode control while maintaining good cross regulation performance and low by driving the output MOSFET with a duty cycle inversely output ripple. proportional to the current into the CONTROL pin that is in excess of the internal supply current of the chip (see Error Amplifier Figure 7). The excess current is the feedback error signal that The shunt regulator can also perform the function of an error appears across R (see Figure 2). This signal is filtered by an RC amplifier in primary side feedback applications. The shunt E network with a typical corner frequency of 7 kHz to reduce the regulator voltage is accurately derived from a temperature- effect of switching noise in the chip supply current generated compensated bandgap reference. The gain of the error by the MOSFET gate driver. The filtered error signal is amplifier is set by the CONTROL pin dynamic impedance. compared with the internal oscillator sawtooth waveform to The CONTROL pin clamps external circuit signals to the V C generate the duty cycle waveform. As the control current voltage level. The CONTROL pin current in excess of the increases, the duty cycle decreases. A clock signal from the supply current is separated by the shunt regulator and flows oscillator sets a latch which turns on the output MOSFET. The through R as a voltage error signal. E pulse width modulator resets the latch, turning off the output MOSFET. Note that a minimum current must be driven into On-Chip Current Limit with External Programmability the CONTROL pin before the duty cycle begins to change. The cycle-by-cycle peak drain current limit circuit uses the output MOSFET ON-resistance as a sense resistor. A current The maximum duty cycle, DC ,is set at a default maximum limit comparator compares the output MOSFET on-state drain MAX value of 78% (typical). However, by connecting the LINE- to source voltage, V with a threshold voltage. High drain DS(ON) SENSE or MULTI-FUNCTION pin (depending on the current causes V to exceed the threshold voltage and turns DS(ON) package) to the rectified DC high voltage bus through a the output MOSFET off until the start of the next clock cycle. resistor with appropriate value, the maximum duty cycle can The current limit comparator threshold voltage is temperature be made to decrease from 78% to 38% (typical) as shown in compensated to minimize the variation of the current limit due Figure 11 when input line voltage increases (see line feed to temperature related changes in R of the output MOSFET. DS(ON) forward with DC reduction). The default current limit of TOPSwitch-GX is preset internally. MAX However, with a resistor connected between EXTERNAL Light Load Frequency Reduction CURRENT LIMIT (X) pin (Y, R or F package) or MULTI- The pulse width modulator duty cycle reduces as the load at FUNCTION (M) pin (P or G package) and SOURCE pin, the power supply output decreases. This reduction in duty current limit can be programmed externally to a lower level cycle is proportional to the current flowing into the CONTROL between 30% and 100% of the default current limit. Please pin. As the CONTROL pin current increases, the duty cycle refer to the graphs in the typical performance characteristics decreases linearly towards a duty cycle of 10%. Below 10% section for the selection of the resistor value. By setting current duty cycle, to maintain high efficiency at light loads, the limit low, a larger TOPSwitch-GX than necessary for the power O 11/05 7

TOP242-250 required can be used to take advantage of the lower R for high voltage bus sets UV threshold during power up. Once the DS(ON) higher efficiency/smaller heat sinking requirements. With power supply is successfully turned on, the UV threshold is a second resistor connected between the EXTERNAL lowered to 40% of the initial UV threshold to allow extended CURRENT LIMIT (X) pin (Y, R or F package) or MULTI- input voltage operating range (UV low threshold). If the UV FUNCTION (M) pin (P or G package) and the rectified DC low threshold is reached during operation without the power high voltage bus, the current limit is reduced with increasing supply losing regulation, the device will turn off and stay off line voltage, allowing a true power limiting operation against until UV (high threshold) has been reached again. If the power line variation to be implemented. When using an RCD clamp, supply loses regulation before reaching the UV low threshold, this power limiting technique reduces maximum clamp the device will enter auto-restart. At the end of each auto- voltage at high line. This allows for higher reflected voltage restart cycle (S7), the UV comparator is enabled. If the UV designs as well as reducing clamp dissipation. high threshold is not exceeded the MOSFET will be disabled during the next cycle (see Figure 8). The UV feature can The leading edge blanking circuit inhibits the current limit be disabled independent of the OV feature as shown in comparator for a short time after the output MOSFET is turned Figures 19 and 23. on. The leading edge blanking time has been set so that, if a power supply is designed properly, current spikes caused by Line Overvoltage Shutdown (OV) primary-side capacitances and secondary-side rectifier reverse The same resistor used for UV also sets an overvoltage threshold recovery time should not cause premature termination of the which, once exceeded, will force TOPSwitch-GX output into switching pulse. off-state. The ratio of OV and UV thresholds is preset at 4.5 as can be seen in Figure 11. When the MOSFET is off, the The current limit is lower for a short period after the leading rectified DC high voltage surge capability is increased to the edge blanking time as shown in Figure 52. This is due to voltage rating of the MOSFET (700 V), due to the absence dynamic characteristics of the MOSFET. To avoid triggering of the reflected voltage and leakage spikes on the drain. A the current limit in normal operation, the drain current waveform small amount of hysteresis is provided on the OV threshold to should stay within the envelope shown. prevent noise triggering. The OV feature can be disabled independent of the UV feature as shown in Figures 18 and 32. Line Under-Voltage Detection (UV) At power up, UV keeps TOPSwitch-GX off until the input line Line Feed-Forward with DC Reduction MAX voltage reaches the under-voltage threshold. At power down, The same resistor used for UV and OV also implements line UV prevents auto-restart attempts after the output goes out voltage feed-forward, which minimizes output line ripple and of regulation. This eliminates power down glitches caused reduces power supply output sensitivity to line transients. by slow discharge of the large input storage capacitor present This feed-forward operation is illustrated in Figure 7 by the in applications such as standby supplies. A single resistor different values of I (Y, R or F package) or I (P or G package). L M connected from the LINE-SENSE pin (Y, R or F package) or Note that for the same CONTROL pin current, higher line MULTI-FUNCTION pin (P or G package) to the rectified DC voltage results in smaller operating duty cycle. As an added Oscillator (SAW) DMAX Enable from X, L or M Pin (STOP) Time PI-2637-060600 Figure 10. Synchronization Timing Diagram. O 8 11/05

TOP242-250 feature, the maximum duty cycle DC is also reduced cycles between 4.8 V and 5.8 V (see CONTROL pin operation MAX from 78% (typical) at a voltage slightly higher than the UV section above) and runs entirely off the high voltage DC input, threshold to 30% (typical) at the OV threshold (see Figure 11). but with very low power consumption (160 mW typical at Limiting DC at higher line voltages helps prevent transformer 230 VAC with M or X pins open). When the TOPSwitch-GX MAX saturation due to large load transients in TOP248, TOP249 and is remotely turned on after entering this mode, it will initiate TOP250 forward converter applications. DC of 38% at a normal start-up sequence with soft-start the next time the MAX high line was chosen to ensure that the power capability of the CONTROL pin reaches 5.8 V. In the worst case, the delay from TOPSwitch-GX is not restricted by this feature under normal remote on to start-up can be equal to the full discharge/charge operation. cycle time of the CONTROL pin, which is approximately 125 ms for a 47 µF CONTROL pin capacitor. This Remote ON/OFF and Synchronization reduced consumption remote off mode can eliminate TOPSwitch-GX can be turned on or off by controlling the expensive and unreliable in-line mechanical switches. It also current into the LINE-SENSE pin or out from the EXTERNAL allows for microprocessor controlled turn-on and turn-off CURRENT LIMIT pin (Y, R or F package) and into or out sequences that may be required in certain applications such as from the MULTI-FUNCTION pin (P or G package) (see inkjet and laser printers. Figure 11). In addition, the LINE-SENSE pin has a 1 V threshold comparator connected at its input. This voltage Soft-Start threshold can also be used to perform remote ON/OFF Two on-chip soft-start functions are activated at start-up with a control. This allows easy implementation of remote duration of 10 ms (typical). Maximum duty cycle starts from ON/OFF control of TOPSwitch-GX in several different ways. 0% and linearly increases to the default maximum of 78% at A transistor or an optocoupler output connected between the end of the 10 ms duration and the current limit starts from the EXTERNAL CURRENT LIMIT or LINE-SENSE pins about 85% and linearly increases to 100% at the end of the (Y, R or F package) or the MULTI-FUNCTION pin (P or G 10 ms duration. In addition to start-up, soft-start is also package) and the SOURCE pin implements this function with activated at each restart attempt during auto-restart and when “active-on” (Figures 22, 29 and 36) while a transistor or an restarting after being in hysteretic regulation of CONTROL optocoupler output connected between the LINE-SENSE pin pin voltage (V ), due to remote OFF or thermal shutdown C (Y, R or F package) or the MULTI-FUNCTION (P or G package) conditions. This effectively minimizes current and voltage pin and the CONTROL pin implements the function with stresses on the output MOSFET, the clamp circuit and the “active-off” (Figures 23 and 37). output rectifier during start-up. This feature also helps minimize output overshoot and prevents saturation of the When a signal is received at the LINE-SENSE pin or the transformer during start-up. EXTERNAL CURRENT LIMIT pin (Y, R or F package) or the MULTI-FUNCTION pin (P or G package) to disable the Shutdown/Auto-Restart output through any of the pin functions such as OV, UV and To minimize TOPSwitch-GX power dissipation under fault remote ON/OFF, TOPSwitch-GX always completes its current conditions, the shutdown/auto-restart circuit turns the power switching cycle, as illustrated in Figure 10, before the output is supply on and off at an auto-restart duty cycle of typically 4% forced off. The internal oscillator is stopped slightly before the if an out of regulation condition persists. Loss of regulation end of the current cycle and stays there as long as the disable interrupts the external current into the CONTROL pin. V C signal exists. When the signal at the above pins changes state regulation changes from shunt mode to the hysteretic auto- from disable to enable, the internal oscillator starts the next restart mode as described in CONTROL pin operation section. switching cycle. This approach allows the use of these pins When the fault condition is removed, the power supply output to synchronize TOPSwitch-GX to any external signal with a becomes regulated, V regulation returns to shunt mode, and C frequency between its internal switching frequency and 20 kHz. normal operation of the power supply resumes. As seen above, the remote ON/OFF feature allows the Hysteretic Over-Temperature Protection TOPSwitch-GX to be turned on and off instantly, on a cycle- Temperature protection is provided by a precision analog by-cycle basis, with very little delay. However, remote circuit that turns the output MOSFET off when the junction ON/OFF can also be used as a standby or power switch to temperature exceeds the thermal shutdown temperature turn off the TOPSwitch-GX and keep it in a very low power (140 °C typical). When the junction temperature cools to consumption state for indefinitely long periods. If the below the hysteretic temperature, normal operation resumes TOPSwitch-GX is held in remote off state for long enough providing automatic recovery. A large hysteresis of 70 °C time to allow the CONTROL pin to discharge to the internal (typical) is provided to prevent overheating of the PC board due supply under-voltage threshold of 4.8 V (approximately 32 ms to a continuous fault condition. V is regulated in hysteretic mode C for a 47 µF CONTROL pin capacitance), the CONTROL pin and a 4.8 V to 5.8 V (typical) sawtooth waveform is present on goes into the hysteretic mode of regulation. In this mode, the the CONTROL pin while in thermal shutdown. CONTROL pin goes through alternate charge and discharge O 11/05 9

TOP242-250 Bandgap Reference may be used to lower the switching frequency from 132 kHz in All critical TOPSwitch-GX internal voltages are derived from normal operation to 66 kHz in standby mode for very low a temperature-compensated bandgap reference. This reference standby power consumption. is also used to generate a temperature-compensated current reference, which is trimmed to accurately set the switching LINE-SENSE (L) Pin Operation (Y, R and F Packages) frequency, MOSFET gate drive current, current limit, and the When current is fed into the LINE-SENSE pin, it works as line OV/UV thresholds. TOPSwitch-GX has improved circuitry a voltage source of approximately 2.6 V up to a maximum to maintain all of the above critical parameters within very tight current of +400 µA (typical). At +400 µA, this pin turns into absolute and temperature tolerances. a constant current sink. Refer to Figure 12a. In addition, a comparator with a threshold of 1 V is connected at the pin and High-Voltage Bias Current Source is used to detect when the pin is shorted to the SOURCE pin. This current source biases TOPSwitch-GX from the DRAIN pin and charges the CONTROL pin external capacitance There are a total of four functions available through the use of during start-up or hysteretic operation. Hysteretic operation the LINE-SENSE pin: OV, UV, line feed-forward with DC MAX occurs during auto-restart, remote OFF and over-temperature reduction, and remote ON/OFF. Connecting the LINE-SENSE shutdown. In this mode of operation, the current source pin to the SOURCE pin disables all four functions. The LINE- is switched on and off with an effective duty cycle of SENSE pin is typically used for line sensing by connecting a approximately 35%. This duty cycle is determined by the resistor from this pin to the rectified DC high voltage bus to ratio of CONTROL pin charge (I ) and discharge currents implement OV, UV and DC reduction with line voltage. In C MAX (I and I ). This current source is turned off during normal this mode, the value of the resistor determines the line OV/UV CD1 CD2 operation when the output MOSFET is switching. The effect of thresholds, and the DC is reduced linearly with rectified DC MAX the current source switching will be seen on the DRAIN voltage high voltage starting from just above the UV threshold. The pin waveform as small disturbances and is normal. can also be used as a remote ON/OFF and a synchronization input. Refer to Table 2 for possible combinations of the functions with example circuits shown in Figure 16 through Figure 40. A Using Feature Pins description of specific functions in terms of the LINE-SENSE pin I/V characteristic is shown in Figure 11 (right hand side). FREQUENCY (F) Pin Operation The horizontal axis represents LINE-SENSE pin current with The FREQUENCY pin is a digital input pin available in the positive polarity indicating currents flowing into the pin. The Y, R or F package only. Shorting the FREQUENCY pin to meaning of the vertical axes varies with functions. For those SOURCE pin selects the nominal switching frequency of that control the ON/OFF states of the output such as UV, OV 132 kHz (Figure 13), which is suited for most applications. and remote ON/OFF, the vertical axis represents the enable/ For other cases that may benefit from lower switching disable states of the output. UV triggers at I (+50 µA typical frequency such as noise sensitive video applications, a UV with 30 µA hysteresis) and OV triggers at I (+225 µA 66 kHz switching frequency (half frequency) can be selected by OV typical with 8 µA hysteresis). Between the UV and OV shorting the FREQUENCY pin to the CONTROL pin thresholds, the output is enabled. For line feed-forward with (Figure 14). In addition, an example circuit shown in Figure 15 LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE* Figure Number ▼ 16 17 18 19 20 21 22 23 24 25 26 27 28 29 ✓ Three Terminal Operation ✓ ✓ ✓ ✓ ✓ Under-Voltage ✓ ✓ ✓ ✓ ✓ Overvoltage ✓ ✓ ✓ ✓ Line Feed-Forward (DC ) MAX ✓ Overload Power Limiting ✓ ✓ ✓ ✓ ✓ ✓ External Current Limit ✓ ✓ ✓ ✓ ✓ ✓ ✓ Remote ON/OFF *This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible. Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations. O 10 11/05

TOP242-250 DC reduction, the vertical axis represents the magnitude of for P and G packages. The comparator with a 1 V threshold MAX the DC . Line feed-forward with DC reduction lowers at the LINE-SENSE pin is removed in this case as shown in MAX MAX maximum duty cycle from 78% at I (+60 µA typical) to Figure 2b. All of the other functions are kept intact. However, L(DC) 38% at I (+225 µA). since some of the functions require opposite polarity of input OV current (MULTI-FUNCTION pin), they are mutually exclusive. EXTERNAL CURRENT LIMIT (X) Pin Operation For example, line sensing features cannot be used simultaneously (Y, R and F Packages) with external current limit setting. When current is fed into When current is drawn out of the EXTERNAL CURRENT the MULTI-FUNCTION pin, it works as a voltage source of LIMIT pin, it works as a voltage source of approximately approximately 2.6 V up to a maximum current of +400 µA 1.3 V up to a maximum current of -240 µA (typical). At (typical). At +400 µA, this pin turns into a constant current -240 µA, it turns into a constant current source (refer to sink. When current is drawn out of the MULTI-FUNCTION Figure 12a). pin, it works as a voltage source of approximately 1.3 V up to a maximum current of -240 µA (typical). At -240 µA, it turns There are two functions available through the use of the into a constant current source. Refer to Figure 12b. EXTERNAL CURRENT LIMIT pin: external current limit and remote ON/OFF. Connecting the EXTERNAL CURRENT There are a total of five functions available through the use LIMIT pin to the SOURCE pin disables the two functions. In of the MULTI-FUNCTION pin: OV, UV, line feed-forward high efficiency applications, this pin can be used to reduce the with DC reduction, external current limit and remote MAX current limit externally to a value close to the operating peak ON/OFF. A short circuit between the MULTI-FUNCTION current by connecting the pin to the SOURCE pin through pin and SOURCE pin disables all five functions and forces a resistor. The pin can also be used for remote ON/OFF. TOPSwitch-GX to operate in a simple three terminal mode Table 2 shows several possible combinations using this pin. See like TOPSwitch-II. The MULTI-FUNCTION pin is typically Figure 11 for a description of the functions where the horizontal used for line sensing by connecting a resistor from this pin to axis (left hand side) represents the EXTERNAL CURRENT the rectified DC high voltage bus to implement OV, UV and LIMIT pin current. The meaning of the vertical axes varies DC reduction with line voltage. In this mode, the value MAX with function. For those that control the ON/OFF states of the of the resistor determines the line OV/UV thresholds, and the output such as remote ON/OFF, the vertical axis represents the DC is reduced linearly with increasing rectified DC high MAX enable/disable states of the output. For external current limit, voltage starting from just above the UV threshold. External the vertical axis represents the magnitude of the I . Please current limit programming is implemented by connecting the LIMIT see graphs in the Typical Performance Characteristics section MULTI-FUNCTION pin to the SOURCE pin through a resistor. for the current limit programming range and the selection of However, this function is not necessary in most applications appropriate resistor value. since the internal current limit of the P and G package devices has been reduced, compared to the Y, R and F package MULTI-FUNCTION (M) Pin Operation (P and G devices, to match the thermal dissipation capability of the P Packages) and G packages. It is therefore recommended that the MULTI- The LINE-SENSE and EXTERNAL CURRENT LIMIT pin FUNCTION pin is used for line sensing as described above and functions are combined to a single MULTI-FUNCTION pin not for external current limit reduction. The same pin can also MULTI-FUNCTION PIN TABLE* Figure Number ▼ 30 31 32 33 34 35 36 37 38 39 40 ✓ Three Terminal Operation ✓ ✓ ✓ Under-Voltage ✓ ✓ ✓ Overvoltage ✓ ✓ Line Feed-Forward (DC ) MAX ✓ Overload Power Limiting ✓ ✓ ✓ ✓ External Current Limit ✓ ✓ ✓ ✓ ✓ Remote ON/OFF *This table is only a partial list of many MULTI-FUNCTION pin configurations that are possible. Table 3. Typcial MULTI-FUNCTION Pin Configurations. O 11/05 11

TOP242-250 M Pin X Pin L Pin I I I REM(N) UV OV (Enabled) Output MOSFET Switching (Disabled) Disabled when supply I output goes out of regulation I (Default) LIMIT Current Limit I DC (78.5%) MAX Maximum Duty Cycle I -22 µA -27 µA V + V BG TP V BG Pin Voltage I -250 -200 -150 -100 -50 0 50 100 150 200 250 300 350 400 X and L Pins (Y, R or F Package) and M Pin (P or G Package) Current (µA) Note: This figure provides idealized functional characteristics with typical performance values. Please refer to the parametric table and typical performance characteristics sections of the data sheet for measured data. PI-2636-010802 Figure 11. MULTI-FUNCTION (P or G package), LINSE-SENSE, and EXTERNAL CURRENT LIMIT (Y, R or F package) Pin Characteristics. be used as a remote ON/OFF and a synchronization input in (+50 µA typical) and OV triggers at I (+225 µA typical with OV both modes. Please refer to Table 3 for possible combinations 30 µA hysteresis). Between the UV and OV thresholds, the of the functions with example circuits shown in Figure 30 output is enabled. For external current limit and line feed- through Figure 40. A description of specific functions in terms forward with DC reduction, the vertical axis represents the MAX of the MULTI-FUNCTION pin I/V characteristic is shown in magnitude of the I and DC . Line feed-forward with LIMIT MAX Figure 11. The horizontal axis represents MULTI-FUNCTION DC reduction lowers maximum duty cycle from 78% at I MAX M(DC) pin current with positive polarity indicating currents flowing into (+60 µA typical) to 38% at I (+225 µA). External current OV the pin. The meaning of the vertical axes varies with functions. limit is available only with negative MULTI-FUNCTION For those that control the ON/OFF states of the output such pin current. Please see graphs in the Typical Performance as UV, OV and remote ON/OFF, the vertical axis represents Characteristics section for the current limit programming the enable/disable states of the output. UV triggers at I range and the selection of appropriate resistor value. UV O 12 11/05

TOP242-250 Y, R and F Package CONTROL (C) TOPSwitch-GX 240 µA (Negative Current Sense - ON/OFF, Current Limit Adjustment) V + V EXTERNAL CURRENT LIMIT (X) BG T (Voltage Sense) LINE-SENSE (L) 1 V VBG (Positive Current Sense - Under-Voltage, Overvoltage, ON/OFF Maximum Duty Cycle Reduction) 400 µA PI-2634-022604 Figure 12a. LINE-SENSE (L), and EXTERNAL CURRENT LIMIT (X) Pin Input Simplified Schematic. P and G Package CONTROL (C) TOPSwitch-GX 240 µA (Negative Current Sense - ON/OFF, Current Limit Adjustment) V + V BG T MULTI-FUNCTION (M) VBG (Positive Current Sense - Under-Voltage, Overvoltage, Maximum Duty Cycle Reduction) 400 µA PI-2548-022604 Figure 12b. MULTI-FUNCTION (M) Pin Input Simplified Schematic. O 11/05 13

TOP242-250 Typical Uses of FREQUENCY (F) PIN + + DC DC D D Input Input Voltage CONTROL Voltage CONTROL C C S F S F - - PI-2654-071700 PI-2655-071700 Figure 13. Full Frequency Operation (132 kHz). Figure 14. Half Frequency Operation (66 kHz). + Q can be an optocoupler output. S DC D Input Voltage CONTROL C STANDBY S F 47 kΩ Q S R - 20 HkFΩ 1 nF PI-2656-040501 Figure 15. Half Frequency Standby Mode (For High Standby Efficiency). O 14 11/05

TOP242-250 Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) P ins + + V = I x R UV UV LS V =I xR OV OV LS For RLS = 2 MΩ CLXSF D RLS 2 MΩ VUV = 100 VDC V =450 VDC DC DC OV Input Input DC @100 VDC = 78% MAX Voltage Voltage DC @375 VDC = 38% MAX D L D L CONTROL C S D CONTROL C C - S X F - S PI-2617-050100 PI-2618-081403 Figure 16. Three Terminal Operation (LINE-SENSE and Figure 17. Line-Sensing for Under-Voltage, Overvoltage and Line EXTERNAL CURRENT LIMIT Features Disabled. Feed-Forward. FREQUENCY Pin Tied to SOURCE or CONTROL Pin). + + 2 MΩ VUV = RLS x IUV 2 MΩ VOV = IOV x RLS For Value Shown For Values Shown RLS VUV = 100 VDC RLS VOV = 450 VDC DC DC Input 22 kΩ Input 30 kΩ Voltage Voltage 1N4148 D M D L CONTROL CONTROL C C 6.2 V - S - S PI-2510-040501 PI-2620-040501 Figure 18. Line-Sensing for Under-Voltage Only (Overvoltage Figure 19. Linse-Sensing for Overvoltage Only (Under-Voltage Disabled). Maximum Duty Cycle Reduced at Low Line Disabled). and Further Reduction with Increasing Line Voltage. + For RIL = 12 kΩ + ILIMIT =100% @ 100 VDC ILIMIT = 69% ILIMIT = 63% @ 300 VDC R 2.5 MΩ LS For RIL = 25 kΩ I = 43% LIMIT DC See Figure 54b for DC Input D other resistor values Input D Voltage CONTROL (RIL) Voltage CONTROL C C S X S X RIL RIL - - 6 kΩ PI-2623-092303 PI-2624-040501 Figure 20. Externally Set Current Limit. Figure 21. Current Limit Reduction with Line Voltage. O 11/05 15

TOP242-250 Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.) + + QR can be an QR can be an optocoupler optocoupler output or output or can be replaced by can be replaced a manual switch. by a manual switch. Q R ON/OFF 47 kΩ RMC DC DC Input D Input 45 kΩ Voltage CONTROL Voltage C D L CONTROL S X C Q ON/OFF - R 47 KΩ - S PI-2625-040501 PI-2621-040501 Figure 22. Active-on (Fail Safe) Remove ON/OFF. Figure 23. Active-off Remote ON/OFF. Maximum Duty Cycle Reduced. + QouRt pcuatn o br ec aann boep troecpolaucpeledr + QR QopRt occaonu bpele ar no utput by a manual switch. ON/OFF or can be replaced 47 kΩ RMC by a manual switch. For RIL =12 kΩ 45 kΩ I = 69% DC LIMIT DC Input D For RIL =25 kΩ Input D L Voltage CONTROL C ILIMIT = 43% Voltage CONTROL C S X S X R IL Q ON/OFF RIL - R 47 kΩ - PI-2626-040501 PI-2627-040501 Figure 24. Active-on Remote ON/OFF with Externally Set Current Figure 25. Active-off Remote ON/OFF with Externally Set Current Limit. Limit. + Q can be an optocoupler + VUV = IUV x RLS R 2 MΩ ouRtput or can be replaced VOV = IOV x RLS LS by a manual switch. DC @100 VDC = 78% R 2 MΩ MAX QR For R = 2 MΩ LS DCMAX@375 VDC = 38% LS ON/OFF Q can be an optocoupler 47 kΩ VVUV == 140500 VVDDCC InDpCut D L obuyR tap umt aonr ucaaln s bweit crehp.laced OV DC Voltage CONTROL Input D L C For RIL =12 kΩ Voltage CONTROL ILIMIT = 69% C S X Q R R IL ON/OFF - S - 47 kΩ PI-2622-040501 PI-2628-040501 Figure 26. Active-off Remote ON/OFF with LINE-SENSE. Figure 27. Active-on Remote ON/OFF with LINE-SENSE and EXTERNAL CURRENT LIMIT. O 16 11/05

TOP242-250 Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins (cont.) 3 0 2 + VVUOVV == IIOUVV xx RRLLSS 629-092 + QouRt pcuatn o br ec aann boep troecpolaucpeledr by R 2 MΩ For RLS = 2 MΩ PI-2 a manual switch. LS V = 100 VDC UV V = 450 VDC OV InDpCut D L DCMAX@100 VDC = 78% InDpCut D L 300 kΩ DC @375 VDC = 38% Voltage CONTROL MAX Voltage CONTROL C C For RIL = 12 kΩ S X ILIMIT = 69% S - 1R2IL kΩ Sotehee rF rigeusirset o5r4 vba fluoer s - QR 47 kΩ ON/OFF (R ) to select different IL ILIMIT values PI-2640-040501 Figure 28. Line-Sensing and Externally Set Current Limit. Figure 29. Active-on Remote ON/OFF. Typical Uses of MULTI-FUNCTION (M) Pin + + V = I x R UV UV LS V =I xR C S S OV OV LS M D S S RLS 2 MΩ F oVr URVL =S 1=0 20 MVΩDC DC DC V =450 VDC OV Input Input Voltage Voltage DC @100 VDC = 78% MAX D M C D S D M DCMAX@375 VDC = 38% CONTROL CONTROL C C - S - S PI-2508-081199 PI-2509-040501 Figure 30. Three Terminal Operation (MULIT-FUNCTION Features Figure 31. Line-Sensing for Undervoltage, Over-Voltage and Line Disabled). Feed-Forward. + + 2 MΩ VUV = RLS x IUV 2 MΩ VOV = IOV x RLS For Value Shown For Values Shown RLS VUV = 100 VDC RLS VOV = 450 VDC DC DC Input 22 kΩ Input 30 kΩ 1N4148 Voltage Voltage D M D M CONTROL CONTROL C C 6.2 V - S - S PI-2510-040501 PI-2516-040501 Figure 32. Line-Sensing for Under-Voltage Only (Overvoltage Figure 33. Line-Sensing for Overvoltage Only (Under-Voltage Disabled). Disabled). Maximum Duty Cycle Reduced at Low Line and Further Reduction with Increasing Line Voltage. O 11/05 17

TOP242-250 Typical Uses of MULTI-FUNCTION (M) Pin (cont.) + + For RIL = 12 kΩ ILIMIT = 69% ILIMIT =100% @ 100 VDC RLS 2.5 MΩ ILIMIT = 63% @ 300 VDC For RIL = 25 kΩ I = 43% LIMIT DC DC See Figures 54b, 55b Input Input and 56b for other resistor Voltage values (R ) to select Voltage D M different IIL values. D M LIMIT RIL CONTROL C RIL 6 kΩ CONTROL C - S - S PI-2517-022604 PI-2518-040501 Figure 34. Externally Set Current Limit (Not Normally Required-See Figure 35. Current Limit Reduction with Line Voltage (Not Normally M Pin Operation Description). Required-See M Pin Operation Description). + + Q can be an optocoupler QR can be an optocoupler ouRtput or can be replaced output or can be replaced by a manual switch. by a manual switch. Q DC DC R ON/OFF Input Input 47 kΩ RMC Voltage Voltage D M D M45 kΩ CONTROL CONTROL QR C C ON/OFF 4-7 kΩ S - S PI-2519-040501 PI-2522-040501 Figure 36. Active-on (Fail Safe) Remote ON/OFF. Figure 37. Active-off Remote ON/OFF. Maximum Duty Cycle Reduced. O 18 11/05

TOP242-250 Typical Uses of MULTI-FUNCTION (M) Pin (cont.) + + Q can be an optocoupler Q can be an optocoupler R R output or can be replaced output or can be replaced by a manual switch. by a manual switch. For RIL =12 kΩ QR DC ILIMIT = 69% DC ON/OFF 47 kΩ Input Input For RIL =25 kΩ Voltage I = 43% Voltage RMC 24 kΩ RMC = 2RIL R D M LIMIT D M IL CONTROL CONTROL QR C RIL 12 kΩ C ON/OFF 4-7 kΩ S - S PI-2520-040501 PI-2521-040501 Figure 38. Active-on Remote ON/OFF with Externally Set Current Figure 39. Active-off Remote ON/OFF with Externally Set Current Limit (See M Pin Operation Description). Limit (See M Pin Operation Description). + QR can be an optocoupler output or can be replaced by a manual switch. RLS 2 MΩ Q R DC ON/OFF Input 47 kΩ Voltage For R = 2 MΩ LS D M V = 100 VDC CONTROL UV C VOV = 450 VDC - S PI-2523-040501 Figure 40. Active-off Remote ON/OFF with LINE-SENSE. O 11/05 19

TOP242-250 Application Examples TOPSwitch-GX (guaranteed minimum value of 75% vs. 64% for TOPSwitch-II) allows the use of a smaller input capacitor A High Efficiency, 30 W, Universal Input Power Supply (C1). The extended maximum duty cycle and the higher The circuit shown in Figure 41 takes advantage of several of reflected voltage possible with the RCD clamp also permit the TOPSwitch-GX features to reduce system cost and power the use of a higher primary to secondary turns ratio for T1, supply size and to improve efficiency. This design delivers which reduces the peak reverse voltage experienced by the 30 W at 12 V, from an 85 VAC to 265 VAC input, at an ambient secondary rectifier D8. As a result a 60 V Schottky rectifier of 50 °C, in an open frame configuration. A nominal efficiency can be used for up to 15 V outputs, which greatly improves of 80% at full load is achieved using TOP244Y. power supply efficiency. The frequency reduction feature of the TOPSwitch-GX eliminates the need for any dummy loading The current limit is externally set by resistors R1 and R2 to a for regulation at no load and reduces the no-load/standby value just above the low line operating peak DRAIN current consumption of the power supply. Frequency jitter provides of approximately 70% of the default current limit. This improved margin for conducted EMI, meeting the CISPR 22 allows use of a smaller transformer core size and/or higher (FCC B) specification. transformer primary inductance for a given output power, reducing TOPSwitch-GX power dissipation, while at the same Output regulation is achieved by using a simple Zener sense time avoiding transformer core saturation during startup and circuit for low cost. The output voltage is determined by the output transient conditions. The resistors R1 & R2 provide a Zener diode (VR2) voltage and the voltage drops across the signal that reduces the current limit with increasing line voltage, optocoupler (U2) LED and resistor R6. Resistor R8 provides which in turn limits the maximum overload power at high input bias current to Zener VR2 for typical regulation of ±5% at line voltage. This function in combination with the built-in the 12 V output level, over line and load and component soft-start feature of TOPSwitch-GX, allows the use of a low cost variations. RCD clamp (R3, C3 and D1) with a higher reflected voltage, by safely limiting the TOPSwitch-GX drain voltage, with A High Efficiency, Enclosed, 70 W, Universal Adapter Supply adequate margin under worst case conditions. Resistor R4 The circuit shown in Figure 42 takes advantage of several of the provides line sensing, setting UV at 100 VDC and OV at TOPSwitch-GX features to reduce cost, power supply size and 450 VDC. The extended maximum duty cycle feature of PERFORMANCE SUMMARY Output Power: 30 W CY1 Regulation: ± 4% 2.2 nF Efficiency: ≥ 79% C14 R15 Ripple: ≤ 50 mV pk-pk 1 nF 150 Ω L3 12 V @ 3.3 µH 2.5 A C3 R3 41.7 k VnF 628 WkΩ MBRD18060 56C01 0µF 56C01 1µF 22C01 2µF 35 V 35 V 35 V BR1 600 V D1 RTN UF4005 2A R4 D2 L1 2 MΩ 1N4148 R6 20 mH 1/2 W 150 Ω R8 R1 T1 C6 150 Ω C1 41.7/2 M WΩ 0.1 µF U2 CX1 68 µF TOPSwitch-GX LTV817A 100 nF 400 V D L U1 250 VAC CCOONNTTRROOLL TOP244Y C R5 F1 S X F 6.8 Ω VR2 J1 3.15 A 1N5240C 10 V, 2% L R2 C5 9.09 kΩ 47 µF 10 V N PI-2657-081204 Figure 41. 30 W Power Supply using External Current Limit Programming and Line Sensing for UV and OV. O 20 11/05

TOP242-250 increase efficiency. This design delivers 70 W at 19 V, from an reduce Zener clamp dissipation. With a switching frequency of 85 VAC to 265 VAC input, at an ambient of 40 °C, in a small 132 kHz, a PQ26/20 core can be used to provide 70 W. To sealed adapter case (4” x 2.15” x 1”). Full load efficiency is maximize efficiency, by reducing winding losses, two output 85% at 85 VAC rising to 90% at 230 VAC input. windings are used each with their own dual 100 V Schottky rectifier (D2 and D3). The frequency reduction feature of the Due to the thermal environment of a sealed adapter, a TOP249Y TOPSwitch-GX eliminates any dummy loading to maintain is used to minimize device dissipation. Resistors R9 and R10 regulation at no load and reduces the no-load consumption of externally program the current limit level to just above the the power supply to only 520 mW at 230 VAC input. Frequency operating peak DRAIN current at full load and low line. This jittering provides conducted EMI meeting the CISPR 22 allows the use of a smaller transformer core size without (FCC B) / EN55022B specification, using simple filter components saturation during startup or output load transients. Resistors (C7, L2, L3 and C6), even with the output earth grounded. R9 and R10 also reduce the current limit with increasing line voltage, limiting the maximum overload power at high input To regulate the output, an optocoupler (U2) is used with a line voltage, removing the need for any protection circuitry on secondary reference sensing the output voltage via a resistor the secondary. Resistor R11 implements an under-voltage and divider (U3, R4, R5, R6). Diode D4 and C15 filter and smooth overvoltage sense as well as providing line feed-forward for the output of the bias winding. Capacitor C15 (1 µF) prevents reduced output line frequency ripple. With resistor R11 set at the bias voltage from falling during zero to full load transients. 2 MΩ, the power supply does not start operating until the DC Resistor R8 provides filtering of leakage inductance spikes, rail voltage reaches 100 VDC. On removal of the AC input, keeping the bias voltage constant even at high output loads. the UV sense prevents the output glitching as C1 discharges, Resistor R7, C9 and C10 together with C5 and R3 provide turning off the TOPSwitch-GX when the output regulation is loop compensation. lost or when the input voltage falls to below 40 V, whichever occurs first. This same value of R11 sets the OV threshold to Due to the large primary currents, all the small signal control 450 V. If exceeded, for example during a line surge, components are connected to a separate source node that is TOPSwitch-GX stops switching for the duration of the surge, Kelvin connected to the SOURCE pin of the TOPSwitch-GX. extending the high voltage withstand to 700 V without device For improved common-mode surge immunity, the bias winding damage. Capacitor C11 has been added in parallel with VR1 to common returns directly to the DC bulk capacitor (C1). C13 C12 C11 C7 2.2 nF D2 PERFORMANCE SUMMARY 0.33 µF 0.022 µF 0.01 µF MBR20100 Output Power: 70 W 400 V 400 V 400 V Y1 Safety Regulation: ± 4% Efficiency: ≥ 84% Ripple: ≤ 120 mV pk-pk No Load Consumption: < 0.52 W @ 230 VAC VR1 D3 P6KE- MBR20100 C3 C14 200 820 µF L1 0.1 µF 19 V BR1 25 V 200 µH 50 V @ 3.6 A RS805 D1 8A 600 V UF4006 C2 C4 RTN D4 820 µF R1 820 µF L2 R11 1N4148 25 V 270 Ω 25 V 820 µH 2 MΩ U2 R4 2A 1/2 W R8 PC817A 31.6 kΩ C1 T1 4.7 Ω R2 1% C6 145000 µVF TOPSwitch-GX 1C 1µ5F 1 kΩ 56R25 Ω 0.1 µF D L 50 V C9 1% X2 L3 TOP249Y 4.7 nF 50 V RT1 75 µH R9 CCOONNTTRROOLL C U1 10 Ω t° 2A 13 MΩ C10 1.7 A R3 R7 0.1 µF F1 S X F 6.8 Ω 56 kΩ 50 V J1 3.15 A R10 C8 U3 VAC L 20.5 kΩ 05.10 µVF C5 TL431 4.7R56 kΩ 65 4176 µVF 1% 5-2 N All resistors 1/8 W 5% unless otherwise stated. 8 PI-2691-042203 Figure 42. 70 W Power Supply using Current Limit Reduction with Line and Line Sensing for UV and OV. O 11/05 21

TOP242-250 A High Efficiency, 250 W, 250-380 VDC Input Power Supply However, VR1 is essential to limit the peak drain voltage The circuit shown in Figure 43 delivers 250 W (48 V @ during start-up and/or overload conditions to below the 700 V 5.2 A) at 84% efficiency using a TOP249 from a 250 VDC to rating of the TOPSwitch-GX MOSFET. 380 VDC input. DC input is shown, as typically at this power level a p.f.c. boost stage would preceed this supply, providing the The secondary is rectifed and smoothed by D2 and C9, C10 and DC input (C1 is included to provide local decoupling). Flyback C11. Three capacitors are used to meet the secondary ripple topology is still usable at this power level due to the high output current requirement. Inductor L2 and C12 provide switching voltage, keeping the secondary peak currents low enough so noise filtering. that the output diode and capacitors are reasonably sized. A simple Zener sensing chain regulates the output voltage. In this example, the TOP249 is at the upper limit of its power The sum of the voltage drop of VR2, VR3 and VR4 plus the capability and the current limit is set to the internal maximum LED drop of U2 gives the desired output voltage. Resistor R6 by connecting the X pin to SOURCE. However, line sensing limits LED current and sets overall control loop DC gain. is implemented by connecting a 2 MΩ resistor from the L pin Diode D4 and C14 provide secondary soft-finish, feeding to the DC rail. If the DC input rail rises above 450 VDC, then current into the CONTROL pin prior to output regulation and TOPSwitch-GX will stop switching until the voltage returns to thus ensuring that the output voltage reaches regulation at start- normal, preventing device damage. up under low line, full load conditions. Resistor R9 provides a discharge path for C14. Capacitor C13 and R8 provide control Due to the high primary current, a low leakage inductance loop compensation and are required due to the gain associated transformer is essential. Therefore, a sandwich winding with with such a high output voltage. a copper foil secondary was used. Even with this technique, the leakage inductance energy is beyond the power capability Sufficient heat sinking is required to keep the TOPSwitch-GX of a simple Zener clamp. Therefore, R2, R3 and C6 are added device below 110 °C when operating under full load, low line in parallel to VR1. These have been sized such that during and maximum ambient temperature. Airflow may also be normal operation, very little power is dissipated by VR1, required if a large heatsink area is not acceptable. the leakage energy instead being dissipated by R2 and R3. C7 2.2 nF Y1 D2 MUR1640CT +2V50D-C380 P6VKRE1200 628R Wk2Ω 628R Wk3Ω 41.C7 k 6nVF 566C301 0VµF 566C301 1VµF 3 µLH2 8A 458. 2V A@ C9 C12 560 µF 68 µF 63 V 63 V D1 BYV26C D2 RTN 1N4148 U2 LTV817A R1 2 MΩ R9 1/2 W T1 10 kΩ C4 C1 1 µF 22 µF 50 V 400 V R6 TOPSwitch-GX 100 Ω C13 D L TOP249Y PERFORMANCE SUMMARY U1 150 nF D4 CCOONNTTRROOLL 63 V 1N4148 Output Power: 250 W C VR2 22 V Line Regulation: ± 1% BZX79B22 Load Regulation: ± 5% R4 Efficiency: ≥ 85% S X F 6.8 Ω VR3 12 V 2C21 µ4F Ripple: < 100 mV pk-pk C3 BZX79B12 R8 63 V 0.1 µF C3 56 Ω No Load Consumption: ≤ 1.4 W (300 VDC) 50 V 47 µF 10 V VR4 12 V BZX79B12 0 V All resistor 1/8 W 5% unless otherwise stated. PI-2692-081204 Figure 43. 250 W, 48 V Power Supply using TOP249. O 22 11/05

TOP242-250 Multiple Output, 60 W, 185-265 VAC Input Power Supply to the relatively large size of C2). An optional MOV (RV1) Figure 44 shows a multiple output supply typical for high end extends the differential surge protection to 6 kV from 4 kV. set-top boxes or cable decoders containing high capacity hard disks for recording. The supply delivers an output power of Leakage inductance clamping is provided by VR1, R5 and C5, 45 W continuous/60 W peak (thermally limited) from an input keeping the DRAIN voltage below 700 V under all conditions. voltage of 185 VAC to 265 VAC. Efficiency at 45 W, Resistor R5 and capacitor C5 are selected such that VR1 185 VAC is ≥ 75%. dissipates very little power except during overload conditions. The frequency jittering feature of TOPSwitch-GX allows the The 3.3 V and 5 V outputs are regulated to ±5% without circuit shown to meet CISPR22B with simple EMI filtering the need for secondary linear regulators. DC stacking (the (C1, L1 and C6) and the output grounded. secondary winding reference for the other output voltages is connected to the cathode of D10 rather than the anode) is used The secondaries are rectified and smoothed by D7 to D11, C7, to minimize the voltage error for the higher voltage outputs. C9, C11, C13, C14, C16 and C17. Diode D11 for the 3.3 V output is a Schottky diode to maximize efficiency. Diode D10 Due to the high ambient operating temperature requirement for the 5 V output is a PN type to center the 5 V output at 5 V. typical of a set-top box (60 °C), the TOP246Y is used to The 3.3 V and 5 V output require two capacitors in parallel to reduce conduction losses and minimize heatsink size. Resistor meet the ripple current requirement. Switching noise filtering R2 sets the device current limit to 80% of typical to limit is provided by L2 to L5 and C8, C10, C12, C15 and C18. overload power. The line sense resistor (R1) protects the Resistor R6 prevents peak charging of the lightly loaded 30 V TOPSwitch-GX from line surges and transients by sensing when output. The outputs are regulated using a secondary reference the DC rail voltage rises to above 450 V. In this condition the (U3). Both the 3.3 V and 5 V outputs are sensed via R11 TOPSwitch-GX stops switching, extending the input voltage and R10. Resistor R8 provides bias for U3 and R7 sets the withstand to 496 VAC, which is ideal for countries with overall DC gain. Resistor R9, C19, R3 and C5 provide loop poor power quality. A thermistor (RT1) is used to prevent compensation. A soft-finish capacitor (C20) eliminates output premature failure of the fuse by limiting the inrush current (due overshoot. PERFORMANCE SUMMARY 1R0 6Ω DU7F4003 30 V @ Output Power: 45 W Cont./60 W Peak 0.03 A R e g3u.3la Vtio: n : ± 5% DU8F5402 457C0 7 µVF 3.L332 Aµ H 15C00 8 µV F 18 V @ 5 V: ± 5% 0.5 A 1128 VV:: ±± 77%% DU9F5402 323C509 VµF 3.L333 Aµ H 1C20501 0Vµ F 12 V @ 30 V: ± 8% 0.6 A ENfofi cLioeandcy C: o nsump tion: ≥07.65 %W 2.CY2 16nF 339C501 1VµF 10C20510 3V µ F 10C20510 6V µ F 3.L34 µ H 1C20501 2Vµ F VR1 R5 5A 5 V @ P6KE170 68 kΩ 3.2 A 2 W C14 C15 DBY10V32-200 102050 V µF 3.L355 Aµ H 21260 VµF 3.3 V @ C5 3 A 1 nF 400 V DM1B1R1045 10C0107 µ F 2C12601 8Vµ F D1-D4 25 V 1N4007 V D6 RTN 1N4937 C2 L1 68 µF 200. 8mAH 400 V 2 RM1Ω 1ND46148 51C0 µ3 VF 15R07 Ω 1Rk51Ω.00 0.CX1 11µF 1/2 W T1 LTUV2817 1R k8Ω 9R.5131 TOPSwitch-GX kΩ RV1 D L TOP246Y 1247 5m Vm CCOONNTTRROOLL C U1 3.R3 9kΩ 0C.11 µ9F F1 C3 J1 3.15 A RT1 S X F 05.10 µVF 6.R83 Ω 185-265 VAC NL t° 11.07 ΩA 9.0R82 kΩ 417C0 5 µVF 21C202 µ0VF UTL3431 1R01 2k PI-2693-081704 Figure 44. 60 W Multiple Output Power Supply using TOP246. O 11/05 23

TOP242-250 Processor Controlled Supply Turn On/Off parking the print heads in the storage position. In the case of A low cost momentary contact switch can be used to turn products with a disk drive, the shutdown procedure may include the TOPSwitch-GX power on and off under microprocessor saving data or settings to the disk. After the shutdown procedure control, which may be required in some applications such as is complete, when it is safe to turn off the power supply, the printers. The low power remote OFF feature allows an microprocessor releases the M pin by turning the optocoupler elegant implementation of this function with very few external U4 off. If the manual switch and the optocouplers U3 and U4 components, as shown in Figure 45. Whenever the push are not located close to the M pin, a capacitor C may be needed M button momentary contact switch P1 is closed by the user, the to prevent noise coupling to the pin when it is open. optocoupler U3 is activated to inform the microprocessor of this action. Initially, when the power supply is off (M pin is The power supply could also be turned on remotely through floating), closing of P1 turns the power supply on by shorting a local area network or a parallel or serial port by driving the the M pin of the TOPSwitch-GX to SOURCE through a diode optocoupler U4 input LED with a logic signal. Sometimes it is (remote ON). When the secondary output voltage V is easier to send a train of logic pulses through a cable (due to AC CC established, the microprocessor comes alive and recognizes that coupling of cable, for example) instead of a DC logic level as the switch P1 is closed through the switch status input that is a wake up signal. In this case, a simple RC filter can be used driven by the optocoupler U3 output. The microprocessor then to generate a DC level to drive U4 (not shown in Figure 45). sends a power supply control signal to hold the power supply This remote on feature can be used to wake up peripherals in the on-state through the optocoupler U4. If the user presses such as printers, scanners, external modems, disk drives, etc., the switch P1 again to command a turn off, the microprocessor as needed from a computer. Peripherals are usually designed detects this through the optocoupler U3 and initiates a shutdown to turn off automatically if they are not being used for a period procedure that is product specific. For example, in the case of of time, to save power. the inkjet printer, the shutdown procedure may include safely V CC (+5 V) + External Wake-up High Voltage Signal DC Input MICRO- Power PROCESSOR/ Supply 100 kΩ CONTROLLER ON/OFF 27 kΩ U2 Control 1N4148 LOGIC LOGIC 1N4148 INPUT OUTPUT 6.8 kΩ D M TOPSwitch-GX U4 CONTROL U3 C 6.8 kΩ C P1 1 nMF S F U1 47 µF U3 P1 Switch LTV817A Status U4 LTV817A RETURN PI-2561-030805 Figure 45. Remote ON/OFF using Microcontroller. O 24 11/05

TOP242-250 In addition to using a minimum number of components, the switch and subsequent bouncing of the switch has no TOPSwitch-GX provides many technical advantages in this effect. If necessary, the microprocessor could implement type of application: the switch debouncing in software during turn-off, or a filter capacitor can be used at the switch status input. 1. Extremely low power consumption in the off mode: 80 mW typical at 110 VAC and 160 mW typical at 230 VAC. This 4. No external current limiting circuitry is needed for the is because, in the remote OFF mode, the TOPSwitch-GX operation of the U4 optocoupler output due to internal consumes very little power and the external circuitry does limiting of M pin current. not consume any current (either M, L or X pin is open) from the high voltage DC input. 5. No high voltage resistors to the input DC voltage rail are required to power the external circuitry in the primary. Even 2. A very low cost, low voltage/current, momentary contact the LED current for U3 can be derived from the CONTROL switch can be used. pin. This not only saves components and simplifies layout, but also eliminates the power loss associated with the high 3. No debouncing circuitry for the momentary switch is voltage resistors in both ON and OFF states. required. During turn-on, the start-up time of the power supply (typically 10 ms to 20 ms) plus the microprocessor 6. Robust design: There is no ON/OFF latch that can be initiation time act as a debouncing filter, allowing a turn-on accidentally triggered by transients. Instead, the power only if the switch is depressed firmly for at least the above supply is held in the ON-state through the secondary-side delay time. During turn-off, the microprocessor initiates microprocessor. the shutdown sequence when it detects the first closure of O 11/05 25

TOP242-250 Key Application Considerations TOPSwitch-II vs. TOPSwitch-GX Table 4 compares the features and performance differences Other features increase the robustness of design, allowing cost between TOPSwitch-GX and TOPSwitch-II. Many of the new savings in the transformer and other power components. features eliminate the need for additional discrete components. TOPSwitch-GX Function TOPSwitch-II TOPSwitch-GX Figures Advantages Soft-Start N/A* 10 ms • Limits peak current and voltage component stresses during start- up • Eliminates external components used for soft-start in most applications • Reduces or eliminates output overshoot External Current N/A* Programmable 100% 11,20,21, • Smaller transformer Limit to 30% of default 24,25,27, • Higher efficiency current limit 28,34,35, • Allows power limiting (constant 38,39 overload power independent of line voltage) • Allows use of larger device for lower losses, higher efficiency and smaller heatsink DC 67% 78% 7 • Smaller input cap (wider dynamic MAX range) • Higher power capability (when used with RCD clamp for large V ) OR • Allows use of Schottky secondary rectifier diode for up to 15 V output for high efficiency Line Feed-Forward N/A* 78% to 38% 7,11,17, • Rejects line ripple with DC Reduction 26,27,28, MAX 31,40 Line OV Shutdown N/A* Single resistor 11,17,19, • Increases voltage withstand programmable 26,27,28 capability against line surge 31,33,40 Line UV Detection N/A* Single resistor 11,17,18, • Prevents auto-restart glitches programmable 26,27,28, during power down 31,32,40 Switching Frequency 100 kHz ±10% 132 kHz ±6% 13,15 • Smaller transformer • Below start of conducted EMI limits Table 4. Comparison Between TOPSwitch-II and TOPSwitch-GX (continued on next page). *Not available O 26 11/05

TOP242-250 TOPSwitch-GX Function TOPSwitch-II TOPSwitch-GX Figures Advantages Switching Frequency N/A* 66 kHz ±7% 14,15 • Lower losses when using RC and Option (Y, R and F RCD snubber for noise reduction Packages) in video applications • Allows for higher efficiency in standby mode • Lower EMI (second harmonic below 150 kHz) Frequency Jitter N/A* ±4 kHz @ 132 kHz 9,46 • Reduces conducted EMI ±2 kHz @ 66 kHz Frequency Reduction N/A* At a duty cycle below 7 • Zero load regulation without 10% dummy load • Low power consumption at no-load Remote ON/OFF N/A* Single transistor or 11,22,23, • Fast ON/OFF (cycle-by-cycle) optocoupler interface 24,25,26, • Active-on or active-off control or manual switch 27,29,36, • Low consumption in remote off 37,38,39, state 40 • Active-on control for fail-safe • Eliminates expensive in-line on/off switch • Allows processor controlled turn on/off • Permits shutdown/wake-up of peripherals via LAN or parallel port Synchronization N/A* Single transistor or • Synchronization to external lower optocoupler interface frequency signal • Starts new switching cycle on demand Thermal Shutdown 125 °C min. Hysteretic 130 °C • Automatic recovery from thermal Latched min. shutdown (with fault 75 °C hysteresis) • Large hysteresis prevents circuit board overheating Current Limit ±10% (@ 25 °C) ±7% (@ 25 °C) • 10% Higher power capability due Tolerance -8% (0 °C to -4% Typical to tighter tolerance 100 °C) (0 °C to 100 °C)** DIP 0.037” / 0.94 mm 0.137” / 3.48 mm • Greater immunity to arcing as a DRAIN result of build-up of dust, debris Creepage SMD 0.037” / 0.94 mm 0.137” / 3.48 mm and other contaminants at Package TO-220 0.046” / 1.17 mm 0.068” / 1.73 mm DRAIN Creepage at 0.045” / 1.14 mm 0.113” / 2.87 mm • Performed leads accommodate PCB for Y, R and F (R and F Package (performed leads) large creepage for PCB layout Packages N/A*) • Easier to meet Safety (UL/VDE) Table 4 (cont). Comparison Between TOPSwitch-II and TOPSwitch-GX. *Not available **Current limit set to internal maximum O 11/05 27

TOP242-250 TOPSwitch-GX Function TOPSwitch-FX TOPSwitch-GX Advantages Light Load Operation Cycle skipping Frequency and duty • Improves light load efficiency cycle reduction • Reduces no-load consumption Line Sensing/Exter- Line sensing and Line sensing and • Additional design flexibility allows all nally Set Current externally set current externally set current features to be used simultaneously Limit (Y, R and F limit mutually limit possible simul- Packages) exclusive (M pin) taneously (functions split onto L and X pins Current Limit 100% to 40% 100% to 30% • Minimizes transformer core size in highly Programming Range continuous designs P/G Package Current Identical to Y TOP243-246 P and • Matches device current limit to package Limits package G packages internal dissipation capability current limits reduced • Allows more continuous design to lower device dissipation (lower RMS currents) Y/R/F Package 100% (R and F 90% (for equivalent • Minimizes transformer core size Current Limits package N/A*) R ) • Optimizes efficiency for most applications DS(ON) Thermal Shutdown 125 °C min. 130 °C min. • Allows higher output powers in high 70 °C hysteresis 75 °C hysteresis ambient temperature applications 90 µA 60 µA • Reduces output line frequency ripple at low line Maximum Duty Cycle • DC reduction optimized for forward Reduction Threshold MAX designs using TOP248, TOP249 and TOP250 Line Under-Voltage N/A* 40% of positive • Provides a well defined turn-off threshold Negative (turn-off) (turn-on) threshold as the line voltage falls Threshold Soft-Start 10 ms (duty cycle) 10 ms (duty cycle + • Gradually increasing current limit in current limit) addition to duty cycle during soft-start further reduces peak current and voltage • Further reduces component stresses during start up Table 5. Comparison Between TOPSwitch-FX and TOPSwitch-GX. *Not available TOPSwitch-FX vs. TOPSwitch-GX to TOP250: Higher output voltages, with a maximum output current of 6 A. Table 5 compares the features and performance differences between TOPSwitch-GX and TOPSwitch-FX. Many of the new For all devices, a 100 VDC minimum for 85-265 VAC and features eliminate the need for additional discrete components. 250 VDC minimum for 230 VAC are assumed and sufficient Other features increase the robustness of design, allowing cost heat sinking to keep device temperature ≤100 °C. Power savings in the transformer and other power components. levels shown in the power table for the R package device assume 6.45 cm2 of 610 g/m2 copper heat sink area in an TOPSwitch-GX Design Considerations enclosed adapter, or 19.4 cm2 in an open frame. Power Table TOPSwitch-GX Selection Data sheet power table (Table 1) represents the maximum Selecting the optimum TOPSwitch-GX depends upon required practical continuous output power based on the following maximum output power, efficiency, heat sinking constraints conditions: TOP242 to TOP246: 12 V output, Schottky output and cost goals. With the option to externally reduce current diode, 150 V reflected voltage (V ) and efficiency estimates limit, a larger TOPSwitch-GX may be used for lower power OR from curves contained in application note AN-29. TOP247 applications where higher efficiency is needed or minimal heat sinking is available. O 28 11/05

TOP242-250 Input Capacitor transformer saturation during start-up. Also, soft-start limits the The input capacitor must be chosen to provide the minimum DC amount of output voltage overshoot and, in many applications, voltage required for the TOPSwitch-GX converter to maintain eliminates the need for a soft-finish capacitor. regulation at the lowest specified input voltage and maximum output power. Since TOPSwitch-GX has a higher DC than EMI MAX TOPSwitch-II, it is possible to use a smaller input capacitor. The frequency jitter feature modulates the switching frequency For TOPSwitch-GX, a capacitance of 2 µF per watt is possible for over a narrow band as a means to reduce conducted EMI peaks universal input with an appropriately designed transformer. associated with the harmonics of the fundamental switching frequency. This is particularly beneficial for average detection Primary Clamp and Output Reflected Voltage V mode. As can be seen in Figure 46, the benefits of jitter increase OR A primary clamp is necessary to limit the peak TOPSwitch-GX with the order of the switching harmonic due to an increase in drain to source voltage. A Zener clamp requires few parts and frequency deviation. takes up little board space. For good efficiency, the clamp Zener should be selected to be at least 1.5 times the output The FREQUENCY pin of TOPSwitch-GX offers a switching reflected voltage V , as this keeps the leakage spike conduction frequency option of 132 kHz or 66 kHz. In applications that OR time short. When using a Zener clamp in a universal input require heavy snubbers on the drain node for reducing high application, a V of less than 135 V is recommended to allow OR for the absolute tolerances and temperature variations of the 80 Zabnreedna ewkrd.i lo Tl wahlniss ov w okileltlea pegn ets houefr meth eaefx fiTimcOieuPnmSt w odpirtaecirhna- tGviooXnlt Maogf Oeth bSeeF clEolawTm. tph ec irractueidt 6700 TOPSwitch-II (no jitter) PI-2576-010600 V) 50 µ A high VOR is required to take full advantage of the wider DCMAX dB 40 of TOPSwitch-GX. An RCD clamp provides tighter clamp e ( d 30 voltage tolerance than a Zener clamp and allows a V as high u as 150 V. RCD clamp dissipation can be minimized byO rRe ducing plit 20 m the external current limit as a function of input line voltage (see -10 A Figures 21 and 35). The RCD clamp is more cost effective than 0 the Zener clamp but requires more careful design (see Quick EN55022B (QP) -10 Design Checklist). EN55022B (AV) -20 0.15 1 10 30 Output Diode The output diode is selected for peak inverse voltage, output Frequency (MHz) current, and thermal conditions in the application (including Figure 46a. TOPSwitch-II Full Range EMI Scan (100 kHz, No Jitter). heatsinking, air circulation, etc.). The higher DC of MAX TOPSwitch-GX, along with an appropriate transformer turns re1af2tfi iVoci,,e 3cn0ac nyW oa lndl oeoswuigt ptnhu eut svuionslget aaog f6e s0a aV6s 0 hS icVghh oS atctskh y1o 5tft okVry t( hsdeeioe o dFueit gpfuuortr e d h4iio1gd:h e eA)r. 678000 TOPSwitch-GX (with jitter) PI-2577-010600 V) Bias Winding Capacitor µ 50 B Due to the low frequency operation at no-load a 1 µF bias d 40 winding capacitor is recommended. de ( 30 u Soft-Start mplit 20 Generally, a power supply experiences maximum stress at A -10 start-up before the feedback loop achieves regulation. For a 0 period of 10 ms, the on-chip soft-start linearly increases the duty EN55022B (QP) -10 EN55022B (AV) cycle from zero to the default DC at turn on. In addition, MAX -20 the primary current limit increases from 85% to 100% over the 0.15 1 10 30 same period. This causes the output voltage to rise in an orderly Frequency (MHz) manner, allowing time for the feedback loop to take control of the duty cycle. This reduces the stress on the TOPSwitch-GX Figure 46b. TOPSwitch-GX Full Range EMI Scan (132 kHz, With MOSFET, clamp circuit and output diode(s), and helps prevent Jitter) with Identical Circuitry and Conditions. O 11/05 29

TOP242-250 frequency radiated noise (for example, video noise sensitive SOURCE connection trace should not be shared by the main applications such as VCR, DVD, monitor, TV, etc.), operating MOSFET switching currents. All SOURCE pin referenced at 66 kHz will reduce snubber loss resulting in better efficiency. components connected to the MULTI-FUNCTION, LINE- Also, in applications where transformer size is not a concern, SENSE or EXTERNAL CURRENT LIMIT pins should use of the 66 kHz option will provide lower EMI and higher also be located closely between their respective pin and efficiency. Note that the second harmonic of 66 kHz is still SOURCE. Once again, the SOURCE connection trace of these below 150 kHz, above which the conducted EMI specifications components should not be shared by the main MOSFET get much tighter. switching currents. It is very critical that SOURCE pin switching currents are returned to the input capacitor negative For 10 W or below, it is possible to use a simple inductor in terminal through a seperate trace that is not shared by the place of a more costly AC input common mode choke to meet components connected to CONTROL, MULTI-FUNCTION, worldwide conducted EMI limits. LINE-SENSE or EXTERNAL CURRENT LIMIT pins. This is because the SOURCE pin is also the controller ground Transformer Design reference pin. It is recommended that the transformer be designed for maximum operating flux density of 3000 Gauss and a peak flux Any traces to the M, L or X pins should be kept as short as density of 4200 Gauss at maximum current limit. The turns ratio possible and away from the DRAIN trace to prevent noise should be chosen for a reflected voltage (V ) no greater than coupling. LINE-SENSE resistor (R1 in Figures 47-49) should OR 135 V when using a Zener clamp, or 150 V (max) when using be located close to the M or L pin to minimize the trace length an RCD clamp with current limit reduction with line voltage on the M or L pin side. (overload protection). In addition to the 47 µF CONTROL pin capacitor, a high For designs where operating current is significantly lower than frequency bypass capacitor in parallel may be used for better the default current limit, it is recommended to use an externally noise immunity. The feedback optocoupler output should set current limit close to the operating peak current to reduce peak also be located close to the CONTROL and SOURCE pins of flux density and peak power (see Figures 20 and 34). In most TOPSwitch-GX. applications, the tighter current limit tolerance, higher switching frequency and soft-start features of TOPSwitch-GX contribute Y-Capacitor to a smaller transformer when compared to TOPSwitch-II. The Y-capacitor should be connected close to the secondary output return pin(s) and the positive primary DC input pin of Standby Consumption the transformer. Frequency reduction can significantly reduce power loss at light or no load, especially when a Zener clamp is used. For Heat Sinking very low secondary power consumption, use a TL431 regulator The tab of the Y package (TO-220) or F package (TO-262) for feedback control. Alternately, switching losses can be is internally electrically tied to the SOURCE pin. To avoid significantly reduced by changing from 132 kHz in normal circulating currents, a heat sink attached to the tab should not operation to 66 kHz under light load conditions. be electrically tied to any primary ground/source nodes on the PC board. TOPSwitch-GX Layout Considerations When using a P (DIP-8), G (SMD-8) or R (TO-263) package, As TOPSwitch-GX has additional pins and operates at a copper area underneath the package connected to the much higher power levels compared to previous TOPSwitch SOURCE pins will act as an effective heat sink. On double families, the following guidelines should be carefully sided boards (Figure 49), top side and bottom side areas followed. connected with vias can be used to increase the effective heat sinking area. Primary Side Connections Use a single point (Kelvin) connection at the negative terminal In addition, sufficient copper area should be provided at of the input filter capacitor for the TOPSwitch-GX SOURCE the anode and cathode leads of the output diode(s) for heat pin and bias winding return. This improves surge capabilities sinking. by returning surge currents from the bias winding directly to the input filter capacitor. In Figures 47, 48 and 49, a narrow trace is shown between the output rectifier and output filter capacitor. This trace acts The CONTROL pin bypass capacitor should be located as as a thermal relief between the rectifier and filter capacitor to close as possible to the SOURCE and CONTROL pins and its prevent excessive heating of the capacitor. O 30 11/05

TOP242-250 Safety Spacing Maximize hatched copper areas ( ) for optimum Y1- heat sinking Capacitor + Output Rectifier Output Filter Capacitor HV Input Filter Capacitor - PRI T r BIAS a SEC n s PRI f S S D o r m e TOPSwitch-GX BIAS r TOP VIEW S S C M Opto- R1 coupler - DC + R2 Out PI-2670-042301 Figure 47. Layout Consideratiions for TOPSwitch-GX using P or G Package. Safety Spacing + CapYa1c-itor Maximize hatched copper areas ( ) for optimum heat sinking Input Filter Capacitor HV Output Rectifier Output Filter Capacitor - T r SEC a TOPSwitch-GX n D s f o X r L m C e TOP VIEW r Opto- R1 Heat Sink coupler - DC + Out PI-2669-042301 Figure 48. Layout Consideratiions for TOPSwitch-GX using Y or F Package. O 11/05 31

TOP242-250 Solder Side Output Filter Capacitors Safety Spacing Component Side Y1- + Capacitor TOP VIEW HV T PRI r a Input Filter n Capacitor PRI s - f SEC o r R1a - 1c m e r BIAS D S X L - DC + C Out Opto- Maximize hatched copper coupler areas ( ) for optimum TOPSwitch-GX heat sinking PI-2734-043001 Figure 49. Layout Considerations for TOPSwitch-GX using R Package. Quick Design Checklist 3. Thermal check – At maximum output power, minimum input voltage and maximum ambient temperature, verify As with any power supply design, all TOPSwitch-GX designs that temperature specifications are not exceeded for should be verified on the bench to make sure that components TOPSwitch-GX, transformer, output diodes and output specifications are not exceeded under worst case conditions. The capacitors. Enough thermal margin should be allowed for following minimum set of tests is strongly recommended: the part-to-part variation of the R of TOPSwitch-GX, DS(ON) as specified in the data sheet. The margin required can 1. Maximum drain voltage – Verify that peak V does not either be calculated from the tolerances or it can be DS exceed 675 V at highest input voltage and maximum accounted for by connecting an external resistance in overload output power. Maximum overload output power series with the DRAIN pin and attached to the same occurs when the output is overloaded to a level just before the heatsink, having a resistance value that is equal to the power supply goes into auto-restart (loss of regulation). difference between the measured R of the device DS(ON) under test and the worst case maximum specification. 2. Maximum drain current – At maximum ambient temperature, maximum input voltage and maximum output load, verify Design Tools drain current waveforms at start-up for any signs of transformer saturation and excessive leading edge current For a discussion on utilizing TOP248, TOP249 and TOP250 spikes. TOPSwitch-GX has a leading edge blanking time of in forward converter configurations, please refer to the 220 ns to prevent premature termination of the ON-cycle. TOPSwitch-GX Forward Design Methodology Application Verify that the leading edge current spike is below the Note. allowed current limit envelope (see Figure 52) for the drain current waveform at the end of the 220 ns blanking Up-to-date information on design tools can be found at the period. Power Integrations website: www.powerint.com O 32 11/05

TOP242-250 ABSOLUTE MAXIMUM RATINGS(1,4) DRAIN Voltage ................................... ............... -0.3 V to 700 V CURRENT LIMIT Pin Voltage ........................-0.3 V to 4.5 V DRAIN Peak Current: TOP242......................................0.72 A MULTI-FUNCTION Pin Voltage ........................-0 .3 V to 9 V TOP243....................................... 1.44 A FREQUENCY Pin Voltage ..................................-0.3 V to 9 V TOP244..........................................2.16 A Storage Temperature ..................................... -65 °C to 150 °C TOP245....................................... 2.88 A Operating Junction Temperature(2) ................ -40 °C to 150 °C TOP246..........................................4.32 A Lead Temperature(3) ...................................................... 260 °C TOP247..........................................5.76 A Notes: TOP248..........................................7.20 A 1. All voltages referenced to SOURCE, T = 25 °C. A TOP249..........................................8.64 A 2. Normally limited by internal circuitry. TOP250 ........................................10.08 A 3. 1/16 in. from case for 5 seconds. CONTROL Voltage ................................................ -0.3 V to 9 4. Maximum ratings specified may be applied one at a time, VCONTROL Current .................................................... 100 mA without causing permanent damage to the product. LINE SENSE Pin Voltage ................................... -0.3 V to 9 V Exposure to Absolute Maximum Rating conditions for extended periods of time may affect product reliability. THERMAL IMPEDANCE Thermal Impedance: Y or F Package: Notes: (θ )(1) .......................... .....................80 °C/W 1. Free standing with no heatsink. JA (θ )(2) ................................................ .2 °C/W 2. Measured at the back surface of tab. JC P or G Package: 3. Soldered to 0.36 sq. in. (232 mm2), 2 oz. (610 g/m2) (θ ) ............................70 °C/W(3); 60 °C/W(4) copper clad. JA (θ )(5) ................................................11 °C/W 4. Soldered to 1 sq. in. (645 mm2), 2 oz. (610 g/m2) copper clad. JC R Package: 5. Measured on the SOURCE pin close to plastic interface. (θ ) ..........80 °C/W(7); 40 °C/W(4); 30 °C/W(6) 6. Soldered to 3 sq. in. (1935 mm2), 2 oz. (610 g/m2) copper clad. JA (θ )(5) ..................................................2 °C/W 7. Soldered to foot print area, 2 oz. (610 g/m2) copper clad. JC Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) CONTROL FUNCTIONS FREQUENCY Pin Switching 124 132 140 I = 3 mA; Connected to SOURCE Frequency f C kHz OSC T = 25 °C FREQUENCY Pin (average) J 61.5 66 70.5 Connected to CONTROL Duty Cycle at ONSET of DC 10 % Frequency (ONSET) Reduction Switching 132 kHz Operation 30 Frequency near f kHz OSC(DMIN) 0% Duty Cycle 66 kHz Operation 15 Frequency Jitter 132 kHz Operation ±4 ∆f kHz Deviation 66 kHz Operation ±2 Frequency Jitter f 250 Hz Modulation Rate M O 11/05 33

TOP242-250 Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) CONTROL FUNCTIONS (cont.) I ≤ I or I ≤ I 75 78 83 L L(DC) M M(DC) I or I = 190 µA L M 28 38 50 TOP242-247 I or I = 100 µA Maximum Duty L M 66.5 DC I = I TOP242-247 % Cycle MAX C CD1 I = 190 µA L 33 41.3 49.5 TOP248-250 I = 100 µA L 60 66.8 73.5 TOP248-250 Soft-Start Time t T = 25 °C; DC to DC 10 15 ms SOFT J MIN MAX PWM Gain DC I = 4 mA; T = 25 °C -28 -23 -18 %/mA reg C J PWM Gain See Note A -0.01 %/mA/°C Temperature Drift TOP242-245 1.2 2.0 3.0 External Bias I See Figure 7 TOP246-249 1.6 2.6 4.0 mA Current B TOP250 1.7 2.7 4.2 CONTROL TOP242-245 6.0 7.0 Current at 0% I T = 25 °C TOP246-249 6.6 8.0 mA C(OFF) J Duty Cycle TOP250 7.3 8.5 Dynamic I = 4 mA; T = 25 °C Z C J 10 15 22 Ω Impedance C See Figure 51 Dynamic Impedance 0.18 %/°C Temperature Drift CONTROL Pin 7 kHz Internal Filter Pole SHUTDOWN/AUTO-RESTART CONTROL Pin V = 0 V -5.0 -3.5 -2.0 I T = 25 °C C mA Charging Current C(CH) J V = 5 V -3.0 -1.8 -0.6 C Charging Current See Note A 0.5 %/°C Temperature Drift Auto-Restart Upper Threshold V 5.8 V C(AR)U Voltage Auto-Restart Lower Threshold V 4.5 4.8 5.1 V C(AR)L Voltage O 34 11/05

TOP242-250 Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) SHUTDOWN/AUTO-RESTART (cont.) Auto-Restart V 0.8 1.0 V Hysteresis Voltage C(AR)hyst Auto-Restart Duty DC 4 8 % Cycle (AR) Auto-Restart f 1.0 Hz Frequency (AR) MULTI-FUNCTION (M), LINE-SENSE (L) AND EXTERNAL CURRENT LIMIT (X) INPUTS Line Under- Threshold 44 50 54 µA Voltage Threshold I T = 25 °C Current and Hys- UV J Hysteresis 30 µA teresis (M or L Pin) Line Overvoltage Threshold 210 225 240 µA or Remote ON/OFF Threshold Current I T = 25 °C OV J and Hysteresis Hysteresis 8 µA (M or L Pin) L Pin Voltage V 0.5 1.0 1.6 V Threshold L(TH) Remote ON/OFF Threshold -35 -27 -20 µA Negative Threshold Current I T = 25 °C REM (N) J and Hysteresis Hysteresis 5 µA (M or X Pin) L or M Pin Short I or L(SC) V , V = V 300 400 520 µA Circuit Current I L M C M(SC) X or M Pin Short I or Normal Mode -300 -240 -180 X(SC) V , V = 0 V µA Circuit Current IM(SC) X M Auto-Restart Mode -110 -90 -70 L or M Pin Voltage I or I = 50 µA 1.90 2.50 3.00 L M V ,V V (Positive Current) L M I or I = 225 µA 2.30 2.90 3.30 L M X Pin Voltage I = -50 µA 1.26 1.33 1.40 X V V (Negative Current) X I = -150 µA 1.18 1.24 1.30 X M Pin Voltage I = -50 µA 1.24 1.31 1.39 M V V (Negative Current) M I = -150 µA 1.13 1.19 1.25 M O 11/05 35

TOP242-250 Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) MULTI-FUNCTION, LINSE-SENSE AND EXTERNAL CURRENT LIMIT INPUTS (cont.) Maximum Duty Cycle Reduction I or L(DC) T = 25 °C 40 60 75 µA Onset Threshold I J M(DC) Current X, L or M Pin Remote OFF 0.6 1.0 See Figure 71 Floating DRAIN Supply I mA D(RMT) V = 150 V L or M Pin Shorted Current DRAIN 1.0 1.6 to CONTROL From Remote ON to Drain Turn-On Remote ON Delay t 2.5 µs R(ON) See Note B Remote OFF Minimum Time Before Drain Turn-On t 2.5 µs Setup Time R(OFF) to Disable Cycle, See Note B FREQUENCY INPUT FREQUENCY Pin V See Note B 2.9 V Threshold Voltage F FREQUENCY Pin I V = V 10 40 100 µA Input Current F F C CIRCUIT PROTECTION TOP242 P/G Internal TOP242 Y/R/F 0.418 0.45 0.481 di/dt = 90 mA/µs T = 25 °C J TOP243 P/G Internal 0.697 0.75 0.802 T = 25 °C di/dt = 150 mA/µs J TOP243 Y/R/F Internal 0.837 0.90 0.963 T = 25 °C di/dt = 180 mA/µs J TOP244 P/G Internal 0.930 1.00 1.070 T = 25 °C di/dt = 200 mA/µs J Self Protection TOP244 Y/R/F Internal 1.256 1.35 1.445 Current Limit I T = 25 °C di/dt = 270 mA/µs A LIMIT J (See Note C) TOP245 P/G Internal 1.02 1.10 1.18 T = 25 °C di/dt = 220 mA/µs J TOP245 Y/R/F Internal 1.674 1.80 1.926 T = 25 °C di/dt = 360 mA/µs J TOP246 P/G Internal 1.256 1.35 1.445 T = 25 °C di/dt = 270 mA/µs J TOP246 Y/R/F Internal 2.511 2.70 2.889 T = 25 °C di/dt = 540 mA/µs J TOP247 Y/R/F Internal 3.348 3.60 3.852 T = 25 °C di/dt = 720 mA/µs J O 36 11/05

TOP242-250 Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) CIRCUIT PROTECTION (cont.) TOP248 Y/R/F Internal 4.185 4.50 4.815 T = 25 °C di/dt = 900 mA/µs J Self Protection TOP249 Y/R/F Internal Current Limit I 5.022 5.40 5.778 A LIMIT T = 25 °C di/dt = 1080 mA/µs (See Note C) J TOP250 Y/R/F Internal 5.859 6.30 6.741 T = 25 °C di/dt = 1260 mA/µs J ≤85 VAC 0.75 x (Rectified Line Input) I LIMIT(MIN) Initial Current Limit I See Note B A INIT 265 VAC 0.6 x (Rectified Line Input) I LIMIT(MIN) Leading Edge See Figure 52 t 220 ns Blanking Time LEB T = 25 °C, I = 4 mA J C Current Limit t I = 4 mA 100 ns Delay IL(D) C Thermal Shut- 130 140 150 °C down Temperature Thermal Shut- Ω 75 °C down Hysteresis Power-Up Reset V Figure 53, S1 Open 1.75 3.0 4.25 V Threshold Voltage C(RESET) OUTPUT TOP242 T = 25 °C 15.6 18.0 J I = 50 mA T = 100 °C 25.7 30.0 D J TOP243 T = 25 °C 7.80 9.00 J I = 100 mA T = 100 °C 12.9 15.0 D J TOP244 T = 25 °C 5.20 6.00 J I = 150 mA T = 100 °C 8.60 10.0 D J ON-State TOP245 T = 25 °C 3.90 4.50 R J Ω Resistance DS(ON) I = 200 mA T = 100 °C 6.45 7.50 D J TOP246 T = 25 °C 2.60 3.00 J I = 300 mA T = 100 °C 4.30 5.00 D J TOP247 T = 25 °C 1.95 2.25 J I = 400 mA T = 100 °C 3.22 3.75 D J TOP248 T = 25 °C 1.56 1.80 J I = 500 mA T = 100 °C 2.58 3.00 D J O 11/05 37

TOP242-250 Conditions SOURCE = 0 V; T = -40 to 125 °C Parameter Symbol J Min Typ Max Units See Figure 53 (Unless Otherwise Specified) OUTPUT (cont.) TOP249 TJ = 25 °C 1.30 1.50 ON-State R ID = 600 mA TJ = 100 °C 2.15 2.50 Ω Resistance DS(ON) TOP250 TJ = 25 °C 1.10 1.28 ID = 700 mA TJ = 100 °C 1.85 2.15 OFF-State Drain V , V = Floating; I = 4 mA I L M C 470 µA Leakage Current DSS V = 560 V; T = 125 °C DS J Breakdown V , V = Floating; I = 4 mA BV L M C 700 V Voltage DSS See Note D, T = 25 °C J Rise Time t Measured in a Typical Flyback 100 ns R Fall Time t Converter Application 50 ns F SUPPLY VOLTAGE CHARACTERISTICS DRAIN Supply See Note E 36 V Voltage Shunt Regulator V I = 4 mA 5.60 5.85 6.10 V Voltage C(SHUNT) C Shunt Regulator ±50 ppm/°C Temperature Drift TOP242-245 1.0 1.6 2.5 Output MOSFET I Enabled TOP246-249 1.2 2.2 3.2 CD1 Control Supply/ VX, VL, VM = 0 V TOP250 1.3 2.4 3.65 mA Discharge Current Output MOSFET I Disabled 0.3 0.6 1.3 CD2 V , V , V = 0 V X L M NOTES: A. For specifications with negative values, a negative temperature coefficient corresponds to an increase in magnitude with increasing temperature, and a positive temperature coefficient corresponds to a decrease in magnitude with increasing temperature. B. Guaranteed by characterization. Not tested in production. C. For externally adjusted current limit values, please refer to Figures 54b, 55b and 56b (Current Limit vs. External Current Limit Resistance) in the Typical Performance Characteristics section. The tolerance specified is only valid at full current limit. D. Breakdown voltage may be checked against minimum BV specification by ramping the DRAIN pin voltage up DSS to but not exceeding minimum BV . DSS E. It is possible to start up and operate TOPSwitch-GX at DRAIN voltages well below 36 V. However, the CONTROL pin charging current is reduced, which affects start-up time, auto-restart frequency, and auto-restart duty cycle. Refer to Figure 68, the characteristic graph on CONTROL pin charge current (I ) vs. DRAIN voltage for low C voltage operation characteristics. O 38 11/05

TOP242-250 t2 t1 HV 90% 90% DRAIN D = t1 VOLTAGE t2 10% 0 V PI-2039-033001 Figure 50. Duty Cycle Measurement. 1 tLEB (Blanking Time) 00 nt (mA) 112000 PI-1939-091996 malized) 1111....3210 PI-2022-033 e 80 r 0.9 r o Pin Cur 60 ent (n 0000....8876 IIIINNIITT((MMIINN)) @@ 28655 V VAACC L rr 0.5 NTRO 40 ImDpyendaamnicce= Slo1pe AIN Cu 00..43 IILLIIMMIITT((MMAINX) )@ @ 2 255 ° °CC O 20 R 0.2 C D 0.1 0 0 0 2 4 6 8 10 0 1 2 3 4 5 6 7 8 CONTROL Pin Voltage (V) Time (µs) Figure 51. CONTROL Pin I-V Characteristic. Figure 52. Drain Current Operating Envelope. Y or R Package (X and L Pins) P or G Package (M Pin) S1 470 Ω 0-100 kΩ 5 W 0-100 kΩ S5 5-50 V M 5-50 V 0-60 kΩ 40 V L D 470 Ω CONTROL C C TOPSwitch-GX S2 S4 F X S 0-15 V S3 47 µF 0.1 µF 0-60 kΩ NOTES: 1. This test circuit is not applicable for current limit or output characteristic measurements. 2. For P and G packages, short all SOURCE pins together. PI-2631-081204 Figure 53. TOPSwitch-GX General Test Circuit. O 11/05 39

TOP242-250 BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS The following precautions should be followed when testing while in this auto-restart mode, there is only a 12.5% chance TOPSwitch-GX by itself outside of a power supply. The that the CONTROL pin oscillation will be in the correct state schematic shown in Figure 53 is suggested for laboratory testing (drain active state) so that the continuous drain voltage waveform of TOPSwitch-GX. may be observed. It is recommended that the V power supply C be turned on first and the DRAIN pin power supply second if When the DRAIN pin supply is turned on, the part will be continuous drain voltage waveforms are to be observed. The in the auto-restart mode. The CONTROL pin voltage will be 12.5% chance of being in the correct state is due to the divide- oscillating at a low frequency between 4.8 V and 5.8 V and by-8 counter. Temporarily shorting the CONTROL pin to the the drain is turned on every eigth cycle of the CONTROL pin SOURCE pin will reset TOPSwitch-GX, which then will come oscillation. If the CONTROL pin power supply is turned on up in the correct state. Typical Performance Characteristics PI-2653-031904 1.1 Scaling Factors: 1.0 TOP242 P/G/Y/R/F: .45 200 TOP243 P/G: .75 0.9 TOP243 Y/R/F: .90 180 TOP244 P/G: 1 A) 0.8 TOP244 Y/R/F: 1.35 160 mit ( 0.7 TTOOPP224456 YY//RR//FF:: 12..8700 140 A/s)µ Li TOP247 Y/R/F: 3.60 m ent 0.6 TTOOPP224489 YY//RR//FF : 45..5400 120 dt ( urr 0.5 TOP250 Y/R/F: 6.32 100 di/ C 0.4 80 0.3 60 0.2 40 -250 -200 -150 -100 -50 0 I or I (µA) X M Figure 54a. Current Limit vs. X or M Pin Current (see Figures 55a and 56a for TOP245P/G and TOP246P/G). PI-2652-042303 1.1 Scaling Factors: 1.0 TOP242 P/G/Y/R/F: .45 200 TOP243 P/G: .75 0.9 TOP243 Y/R/F: .90 180 mit (A) 00..78 Minimum Maximum TTTTOOOOPPPP222244444456 PYYY////GRRR///:FFF ::: 112 ... 387 5001 114600 A/s)µ Li TOP247 Y/R/F: 3.60 m ent 0.6 TTOOPP224489 YY//RR//FF : 45..5400 120 dt ( urr 0.5 Typical TOP250 Y/R/F: 6.32 100 di/ C 0.4 80 Maximum and minimum levels 0.3 are based on characterization. 60 0.2 40 0 5K 10K 15K 20K 25K 30K 35K 40K 45K External Current Limit Resistor R (Ω) IL Figure 54b. Current Limit vs. External Current Limit Resistance (see Figures 55b and 56b for TOP245P/G and TOP246P/G). O 40 11/05

TOP242-250 PI-3652-110405 1.1 Scaling Factor: 1.0 TOP245P/G: 1.1 200 0.9 180 A) 0.8 160 mit ( 0.7 140 A/s)µ Li m ent 0.6 120 dt ( urr 0.5 100 di/ C 0.4 80 0.3 60 0.2 40 -250 -200 -150 -100 -50 0 I (µA) M Figure 55a. Current Limit vs. MULTI-FUNCTION Pin Current (TOP245P/G only). PI-3651-110405 1.1 Scaling Factor: 1.0 TOP245P/G: 1.1 200 0.9 180 A) 0.8 160 mit ( 0.7 ROepfeerra ttoio Mn UseLcTtiIoFnUNCTION (M) Pin 140 A/s)µ Li m ent 0.6 Typical 120 dt ( urr 0.5 100 di/ C 0.4 80 0.3 Measured at 25 °C. 60 0.2 40 0 5K 10K 15K 20K 25K 30K 35K 40K 45K External Current Limit Resistor R (Ω) IL Figure 55b. Current Limit vs. External Current Limit Resistance (TOP245P/G only). 1.25 C) 03 5 °1.20 0730 o 21.15 0 °C 653- d t1.10 PI-3 e aliz1.05 m1.00 r o .95 N mit ( .90 25 °C Li .85 nt .80 100 °C e rr .75 u C .70 0 5K 10K 15K 20K 25K 30K 35K 40K 45K External Current Limit Resistor R (Ω) IL Figure 55c. External Current Limit vs. External Current Limit Resistance at 0 °C, 25 °C and 100 °C Junction Temperature (TOP245P/G only). O 11/05 41

TOP242-250 PI-3724-110405 1.1 Scaling Factor: 1.0 TOP246P/G: 1.35 200 0.9 180 A) 0.8 160 mit ( 0.7 140 A/s)µ Li m ent 0.6 120 dt ( urr 0.5 100 di/ C 0.4 80 0.3 60 0.2 40 -250 -200 -150 -100 -50 0 I (µA) M Figure 56a. Current Limit vs. MULTI-FUNCTION Pin Current (TOP246P/G only). PI-3725-110405 1.1 Scaling Factor: 1.0 200 TOP246P/G: 1.35 0.9 180 A) 0.8 160 mit ( 0.7 ROepfeerra ttoio Mn UseLcTtiIoFnUNCTION (M) Pin 140 A/s)µ Li m ent 0.6 Typical 120 dt ( urr 0.5 100 di/ C 0.4 80 0.3 Measured at 25 °C. 60 0.2 40 0 5K 10K 15K 20K 25K 30K 35K 40K 45K External Current Limit Resistor R (Ω) IL Figure 56b. Current Limit vs. External Current Limit Resistance (TOP246P/G only). 1.25 C) 03 5 °1.20 1007 o 21.15 0 °C 726- d t1.10 PI-3 e aliz1.05 m1.00 r o .95 N mit ( .90 25 °C Li .85 nt .80 100 °C e rr .75 u C .70 0 5K 10K 15K 20K 25K 30K 35K 40K 45K External Current Limit Resistor R (Ω) IL Figure 56c. External Current Limit vs. External Current Limit Resistance at 0 °C, 25 °C and 100 °C Junction Temperature (TOP246P/G only). O 42 11/05

TOP242-250 Typical Performance Characteristics (cont.) oltage o 25 C)°1.1 PI-176B-033001 uencyo 25 C)°110...208 PI-1123A-033001 wn Ved t1.0 Freqed t0.6 doaliz ut aliz akm tpm0.4 BreNor OuNor ( (0.2 0.9 0 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 Junction Temperature (°C) Junction Temperature (°C) Figure 57. Breakdown Voltage vs. Temperature. Figure 58. Frequency vs. Temperature. C)11..20 PI-2555-033001 C)11..20 PI-2554-110705 nt Limited to 25 °00..86 nt Limited to 25 °00..86 ez ez CurrNormali0.4 CurrNormali0.4 Uppaasccekk faaoggr eeTssO aoPnn2dly4 .T2 SO-2eP5e20 F4 Yi2g/-uR2r4/eF4s P55/Gc (0.2 (0.2 and 56c for TOP245P/G and TOP246P/G. 0 0 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 Junction Temperature (°C) Junction Temperature (°C) Figure 59. Internal Current Limit vs. Temperature. Figure 60. External Current Limit vs. Temperature with R = 12 kΩ. IL ervoltage Thresholdormalized to 25 C)°11000.....20864 PI-2553-033001 der-Voltage ThresholdNormalized to 25 C)°11000.....20864 PI-2552-033001 Ov(N0.2 Un(0.2 0 0 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 Junction Temperature (°C) Junction Temperature (°C) Figure 62. Under-Voltage Threshold vs. Temperature. Figure 61. Overvoltage Threshold vs. Temperature. O 11/05 43

TOP242-250 Typical Performance Characteristics (cont.) ge (V) 655...050 PI-2688-102700 LIMIT 111...642 V-2X0 =0 1µ.A3 3≤ -I X ≤IX -2x5 0 µ.6A6 kΩ PI-2689-102300 NSE Pin Volta 434...550 AL CURRENT n Voltage (V)100...068 E NPi E S 3.0 ER 0.4 N T LI 2.5 EX 0.2 2.0 0 0 100 200 300 400 -240 -180 -120 -60 0 LINE-SENSE Pin Current (µA) EXTERNAL CURRENT LIMIT Pin Current (µA) Figure 63a. LINE-SENSE Pin Voltage vs. Current. Figure 63b. EXTERNAL CURRENT LIMIT Pin Voltage vs. Current. oltage (V) 65 PI-2542-102700 oltage (V) 111...246 V-2M0 0= µ1A.3 7≤ -I M ≤IM -2x5 1 µ kAΩ PI-2541-102700 n V 4 n V 1.0 Pi Pi N 3 N 0.8 O O TI TI C C 0.6 N 2 N U U TI-F 1 SEexpeanded TI-F 0.4 L Version L 0.2 U U M M 0 0 -300-200-100 0 100 200 300 400 500 -300 -250 -200 -150 -100 -50 0 MULTI-FUNCTION Pin Current (µA) MULTI-FUNCTION Pin Current (µA) Figure 64b. MULTI-FUNCTION Pin Voltage vs. Current Figure 64a. MULTI-FUNCTION Pin Voltage vs. Current. (Expanded). ntC)°11..20 PI-2562-033001 rrentC)°11..20 PI-2563-033001 urreo 25 0.8 d Cuo 25 0.8 OL Ced t0.6 sholed t0.6 TRaliz hrealiz Nm0.4 Tm0.4 CONor set Nor ( n( 0.2 O 0.2 0 0 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 Junction Temperature (°C) Junction Temperature (°C) Figure 65. Control Current Out at 0% Duty Cycle Figure 66. Max. Duty Cycle Reduction Onset Threshold vs. Temperaure. Current vs. Temperature. O 44 11/05

TOP242-250 Typical Performance Characteristics (cont.) 65 PI-2645-010802 A)12.6 VC = 5 V PI-2564-101499 A) m nt ( 4 Pinnt ( Curre 3 STcOaPlin2g5 0F a 1c.t1o7rs: ROL Curre1.2 RAIN 2 TTTOOOPPP222444987 100...086037 CONTrging 0.8 D TOP246 0.50 a 1 TTOOPP224454 00..3235 Ch0.4 TCASE = 25 °C TOP243 0.17 T = 100 °C TOP242 0.08 CASE 0 0 0 2 4 6 8 10 12 14 16 18 20 0 20 40 60 80 100 DRAIN Voltage (V) DRAIN Voltage (V) Figure 67. Output Characteristics. Figure 68. I vs. DRAIN Voltage. C pF)10000 PI-2646-010802 650000 STTcOOaPPlin22g54 09F a 11c..t10o70rs: PI-2650-020802 nce (1000 STcOaPlin2g5 0F a 1c.t1o7rs: W) 400 TTTOOOPPP222444876 000...865370 a TOP249 1.00 m TOP245 0.33 pacit TTTOOOPPP222444876 000...865370 er ( 300 TTOOPP224443 00..2157 Ca TOP245 0.33 ow TOP242 0.08 N 100 TOP244 0.25 P 200 TOP243 0.17 AI TOP242 0.08 R D 100 10 0 0 100 200 300 400 500 600 0 100 200 300 400 500 600 Drain Voltage (V) DRAIN Voltage (V) Figure 69. C vs. DRAIN Voltage. Figure 70. DRAIN Capacitance Power. OSS y CurrentC)11..20 PI-2690-102700 Supplo 25 °0.8 N d t AIze0.6 DRali F m0.4 For ON ote (0.2 m e R 0 -50 0 50 100 150 Junction Temperature (°C) Figure 71. Remote OFF DRAIN Supply Current vs. Temperature. O 11/05 45

TOP242-250 PART ORDERING INFORMATION TOPSwitch Product Family GX Series Number Package Identifier G Plastic SMD-8B (TOP242-246 only) P Plastic DIP-8B (TOP242-246 only) Y Plastic TO-220-7C R Plastic TO-263-7C (available only with TL option) F Plastic TO-262-7C Lead Finish Blank Standard (Sn Pb) N Pure Matte Tin (Pb-Free) (P, G, Y & F Packages) Tape & Reel and Other Options Blank Standard Configurations TOP 242 G N - TL TL Tape & Reel, (G Package: 1000 min., R Package: 750 min.) O 46 11/05

TOP242-250 TO-220-7C .165 (4.19) .185 (4.70) .390 (9.91) .045 (1.14) .146 (3.71) .420 (10.67) .055 (1.40) .156 (3.96) .108 (2.74) REF + .234 (5.94) .261 (6.63) .461 (11.71) .570 (14.48) .495 (12.57) REF. 7° TYP. .670 (17.02) .860 (21.84) REF. .880 (22.35) .080 (2.03) .120 (3.05) .068 (1.73) MIN PIN 1 & 7 PIN 2 & 4 PIN 1 .024 (.61) .010 (.25) M .040 (1.02) .034 (.86) .060 (1.52) .050 (1.27) BSC .012 (.30) .040 (1.02) .024 (.61) .060 (1.52) .150 (3.81) BSC .190 (4.83) .210 (5.33) .050 (1.27) .050 (1.27) Notes: 1. Controlling dimensions are inches. Millimeter dimensions are shown in parentheses. .050 (1.27) 2. Pin numbers start with Pin 1, and continue from left to right when viewed from the front. .050 (1.27) 3. Dimensions do not include mold flash or other protrusions. Mold flash or protrusions shall not .200 (5.08) .180 (4.58) exceed .006 (.15mm) on any side. 4. Minimum metal to metal spacing at the package .100 (2.54) body for omitted pin locations is .068 in. (1.73 mm). PIN 1 PIN 7 5. Position of terminals to be measured at a location .25 (6.35) below the package body. .150 (3.81) .150 (3.81) 6. All terminals are solder plated. Y07C MOUNTING HOLE PATTERN PI-2644-122004 O 11/05 47

TOP242-250 DIP-8B ⊕D S.004 (.10) .137 (3.48) Notes: -E- MINIMUM 1. Package dimensions conform to JEDEC specification MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP) package with .300 inch row spacing. 2. Controlling dimensions are inches. Millimeter sizes are shown in parentheses. 3. Dimensions shown do not include mold flash or other .240 (6.10) protrusions. Mold flash or protrusions shall not exceed .260 (6.60) .006 (.15) on any side. 4. Pin locations start with Pin 1, and continue counter-clock- wise to Pin 8 when viewed from the top. The notch and/or dimple are aids in locating Pin 1. Pin 6 is omitted. Pin 1 5. Minimum metal to metal spacing at the package body for the omitted lead location is .137 inch (3.48 mm). .367 (9.32) 6. Lead width measured at package body. -D- .387 (9.83) 7. Lead spacing measured with the leads constrained to be .057 (1.45) perpendicular to plane T. .068 (1.73) (NOTE 6) .125 (3.18) .015 (.38) .145 (3.68) MINIMUM -T- SEATING .008 (.20) PLANE .120 (3.05) .015 (.38) .140 (3.56) .300 (7.62) BSC .100 (2.54) BSC .048 (1.22) (NOTE 7) .014 (.36) .053 (1.35) .300 (7.62) P08B .022 (.56) ⊕T E D S.010 (.25) M .390 (9.91) PI-2551-121504 SMD-8B ⊕D S.004 (.10) .137 (3.48) Notes: MINIMUM 1. Controlling dimensions are inches. Millimeter sizes are -E- shown in parentheses. 2. Dimensions shown do not include mold flash or other protrusions. Mold flash or protrusions shall not exceed .372 (9.45) .240 (6.10) .006 (.15) on any side. .388 (9.86) .420 .260 (6.60) 3. Pin locations start with Pin 1, ⊕E S.010 (.25) and continue counter-clock- .046 .060 .060 .046 wise to Pin 8 when viewed from the top. Pin 6 is omitted. 4. Minimum metal to metal .080 spacing at the package body Pin 1 Pin 1 for the omitted lead location .100 (2.54) (BSC) .086 is .137 inch (3.48 mm). .186 5. Lead width measured at package body. .286 .367 (9.32) 6. D and E are referenced -D- .387 (9.83) Solder Pad Dimensions datums on the package body. .057 (1.45) .125 (3.18) .068 (1.73) .145 (3.68) (NOTE 5) .004 (.10) .032 (.81) .048 (1.22) .037 (.94) .053 (1.35) .009 (.23) .004 (.10) .036 (0.91) 0 ° -8° .012 (.30) .044 (1.12) G08B PI-2546-121504 O 48 11/05

TOP242-250 TO-263-7C .390 (9.91) .245 (6.22) .045 (1.14) .420 (10.67) MIN .055 (1.40) .055 (1.40) .066 (1.68) .225 (5.72) .326 (8.28) MIN .336 (8.53) .580 (14.73) .620 (15.75) .000 (0.00) .010 (0.25) .208 (5.28) .090 (2.29) Ref. -A- .110 (2.79) .010 (0.25) 0.68 (1.73) LD #1 MIN .012 (0.30) .024 (0.61) .024 (0.61) .100 (2.54) .050 (1.27) 0°- 8° .034 (0.86) REF .315 (8.00) .165 (4.19) Solder Pad .185 (4.70) Dimensions .380 (9.65) .004 (0.10) Notes: 1. Package Outline Exclusive of Mold Flash & Metal Burr. .638 (16.21) 2. Package Outline Inclusive of Plating Thickness. 3. Foot Length Measured at Intercept Point Between Datum A Lead Surface. .128 (3.25) 4. Controlling Dimensions are in Inches. Millimeter Dimensions are shown in Parentheses. R07C .050 (1.27) 5. Minimum metal to metal spacing at the package body .038 (0.97) for the omitted pin locations is .068 in. (1.73 mm). PI-2664-122004 O 11/05 49

TOP242-250 TO-262-7C .045 (1.14) .390 (9.91) .055 (1.40) .420 (10.67) .165 (4.17) .055 (1.40) .185 (4.70) .066 (1.68) .326 (8.28) .495 (12.56) .336 (8.53) 7° TYP. REF. .795 (20.18) .595 (15.10) REF. .080 (2.03) REF. .120 (3.05) .068 (1.73) MIN PIN 1 & 7 PIN 2 & 4 PIN 1 .024 (.61) .010 (.25) M .040 (1.02) .034 (.86) .060 (1.52) .050 (1.27) BSC .012 (.30) .040 (1.06) .024 (.61) .060 (1.52) .150 (3.81) BSC .190 (4.83) .210 (5.33) .050 (1.27) .050 (1.27) Notes: 1. Controlling dimensions are inches. Millimeter dimensions are shown in parentheses. .050 (1.27) 2. Pin numbers start with Pin 1, and continue .050 (1.27) from left to right when viewed from the front. 3. Dimensions do not include mold flash or .200 (5.08) .180 (4.58) other protrusions. Mold flash or protrusions shall not exceed .006 (.15mm) on any side. .100 (2.54) 4. Minimum metal to metal spacing at the pack- PIN 1 PIN 7 age body for omitted pin locations is .068 inch (1.73 mm). .150 (3.81) .150 (3.81) 5. Position of terminals to be measured at a location .25 (6.35) below the package body. F07C MOUNTING HOLE PATTERN 6. All terminals are solder plated. PI-2757-122004 O 50 11/05

TOP242-250 Revision Notes Date D - 11/00 E 1) Added R package (D2PAK). 7/01 2) Corrected abbreviations (s = seconds). 3) Corrected x-axis units in Figure 11 (µA). 4) Added missing external current limit resistor in Figure 25 (R ). IL 5) Corrected spelling. 6) Added caption for Table 4. 7) Corrected Breakdown Voltage parameter condition (T = 25 °C). J 8) Corrected font sizes in figures. 9) Figure 40 replaced. 10) Corrected schematic component values in Figure 44. F 1) Corrected Power Table value. 9/01 G 1) Added TOP250 device and F package (TO-262). 1/02 2) Added R package Thermal Impedance parameters and adjusted Output Power values in Table 1. 3) Adjusted Off-State Current value. H 1) Added note to parameter table for Breakdown Voltage measurement. 9/02 2) Miscellaneous text corrections. I 1) Updated P, Y, R and F package information. 4/03 2) Revised thermal impedances (θ ) for all package types. JA 3) Expanded Maximum Duty Cycle and deleted Maximum Duty Cycle Reduction Slope parameters. 4) Corrected DIP-8B and SMD-8B Package Drawings. J 1) Added TOP245P. 8/03 2) Miscellaneous text corrections. K 1) Corrected typographic errors in Figures 4, 6, 20, 28 and 34; and in MULTI-FUNCTION (M) Pin 9/03 Operation section. L 1) Added TOP246P. 3/04 M 1) Added lead-free ordering information. 12/04 N 1) Updated Maximum Duty Cycle conditions. 4/05 2) Minor error corrections. 3) Added Note 4 to Absolute Maximum Ratings specification. O 1) Added TOP245G and TOP246G 11/05 O 11/05 51

TOP242-250 For the latest updates, visit our website: www.powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES NO WARRANTY HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS. PATENT INFORMATION The products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered by one or more U.S. and foreign patents, or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrationsʼ patents may be found at www.powerint.com. Power Integrations grants its customers a license under certain patent rights as set forth at http://www.powerint.com/ip.htm. LIFE SUPPORT POLICY POWER INTEGRATIONSʼ PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF POWER INTEGRATIONS. As used herein: 1. A Life support device or system is one which, (i) is intended for surgical implant into the body, or (ii) supports or sustains life, and (iii) whose failure to perform, when properly used in accordance with instructions for use, can be reasonably expected to result in significant injury or death to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. The PI logo, TOPSwitch, TinySwitch, LinkSwitch, DPA-Switch, EcoSmart, Clampless, E-Shield, Filterfuse, PI Expert and PI FACTS are trademarks of Power Integrations, Inc. Other trademarks are property of their respective companies. ©Copyright 2005, Power Integrations, Inc. Power Integrations Worldwide Sales Support Locations WORLD HEADQUARTERS GERMANY JAPAN TAIWAN 5245 Hellyer Avenue Rueckertstrasse 3 Keihin Tatemono 1st Bldg 2-12-20 5F, No. 318, Nei Hu Rd., Sec. 1 San Jose, CA 95138, USA. D-80336, Munich Shin-Yokohama, Kohoku-ku, Nei Hu Dist. Main: +1-408-414-9200 Germany Yokohama-shi, Kanagawa ken, Taipei, Taiwan 114, R.O.C. Customer Service: Phone: +49-89-5527-3910 Japan 222-0033 Phone: +886-2-2659-4570 Phone: +1-408-414-9665 Fax: +49-89-5527-3920 Phone: +81-45-471-1021 Fax: +886-2-2659-4550 Fax: +1-408-414-9765 e-mail: eurosales@powerint.com Fax: +81-45-471-3717 e-mail: taiwansales@powerint.com e-mail: usasales@powerint.com e-mail: japansales@powerint.com CHINA (SHANGHAI) INDIA KOREA EUROPE HQ Rm 807-808A 261/A, Ground Floor RM 602, 6FL 1st Floor, St. Jamesʼs House Pacheer Commercial Centre, 7th Main, 17th Cross, Korea City Air Terminal B/D, 159-6 East Street, Farnham 555 Nanjing Rd. West Sadashivanagar Samsung-Dong, Kangnam-Gu, Surrey GU9 7TJ Shanghai, P.R.C. 200041 Bangalore, India 560080 Seoul, 135-728, Korea United Kingdom Phone: +86-21-6215-5548 Phone: +91-80-5113-8020 Phone: +82-2-2016-6610 Phone: +44 (0) 1252-730-140 Fax: +86-21-6215-2468 Fax: +91-80-5113-8023 Fax: +82-2-2016-6630 Fax: +44 (0) 1252-727-689 e-mail: chinasales@powerint.com e-mail: indiasales@powerint.com e-mail: koreasales@powerint.com e-mail: eurosales@powerint.com CHINA (SHENZHEN) ITALY SINGAPORE APPLICATIONS HOTLINE Rm 2206-2207, Block A, Via Vittorio Veneto 12 51 Newton Road World Wide +1-408-414-9660 Electronics Science & Technology Bldg. 20091 Bresso MI #15-08/10 Goldhill Plaza 2070 Shennan Zhong Rd. Italy Singapore, 308900 APPLICATIONS FAX Shenzhen, Guangdong, Phone: +39-028-928-6000 Phone: +65-6358-2160 World Wide +1-408-414-9760 China, 518031 Fax: +39-028-928-6009 Fax: +65-6358-2015 Phone: +86-755-8379-3243 e-mail: eurosales@powerint.com e-mail: singaporesales@powerint.com Fax: +86-755-8379-5828 e-mail: chinasales@powerint.com O 52 11/05

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: P ower Integrations: TOP248FN TOP248YN TOP246FN TOP246PN TOP246YN TOP246GN TOP243R-TL TOP250YN TOP250FN TOP242YN TOP242GN TOP242PN TOP242FN TOP243GN-TL TOP242R-TL TOP250R-TL TOP244R-TL TOP247R-TL TOP244GN-TL TOP246GN-TL TOP248R-TL TOP242GN-TL TOP246R-TL TOP245R-TL TOP249FN TOP249YN TOP245PN TOP245FN TOP245GN TOP245YN TOP245GN-TL TOP249R-TL TOP243GN TOP243YN TOP243FN TOP243PN TOP247FN TOP244FN TOP244PN TOP244YN TOP244GN TOP247YN