MIC2026A/2076A Dual-Channel Power Distribution Switch General Description Features The MIC2026A and MIC2076A are high-side MOSFET • 100mΩ typical RDS(ON) at 5.0V switches optimized for general-purpose power distribution • 140mΩ maximum R at 5.0V DS(ON) requiring circuit protection. The MIC2026A is particularly • 2.7 V to 5.5 V operating range well suited for USB applications. • 500mA minimum continuous current per channel The MIC2026A/2076A are internally current limited and • Short circuit protection with thermal shutdown have thermal shutdown that protects the device and load. • Thermally isolated channels The MIC2076A offers “smart” shutdown that reduces current consumption in fault modes. When the MIC2076A • Soft-start circuit goes into thermal shutdown due to current limiting, the • Fault status flag with 3ms filter eliminates false output is latched off until the switch is reset. The assertions MIC2076A can be reset by removing the load, toggling the • UVLO (Undervoltage lockout) enable input, or cycling VIN. • Reverse current flow blocking (no “body diode”) Both devices employ soft-start circuitry that minimizes • Circuit breaker mode (MIC2076A) inrush current in applications where highly capacitive loads • Pin compatible with the MIC2026/2076 are employed. • Logic-compatible inputs A fault status output flag is asserted during overcurrent or thermal shutdown conditions. Transient faults are internally • Low quiescent current filtered. Applications The MIC2026A/2076A are available in an 8-pin SOIC package. • USB peripherals All support documentation can be found on Micrel’s web • General purpose power switching site at www.micrel.com. • ACPI power distribution • Notebook PCs • PDAs • PC card hot swap _______________________________________________________________________________________________ Typical Application Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com July 2009 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Ordering Information Part Number Enable Temperature Range Package Lead Finish MIC2026A-1YM Active High –40° to +85°C 8- Pin SOIC Pb-Free MIC2026A-2YM Active Low –40° to +85°C 8- Pin SOIC Pb-Free MIC2076A-1YM Active High –40° to +85°C 8- Pin SOIC Pb-Free MIC2076A-2YM Active Low –40° to +85°C 8- Pin SOIC Pb-Free Pin Configuration ENA 1 8 OUTA FLGA 2 7 IN FLGB 3 6 GND ENB 4 5 OUTB 8-Pin SOIC (M) Pin Description Pin Number Pin Name Pin Function 1 ENA Switch A Enable (Input): Logic-compatible, enable input. Active high (-1) or active low (-2). 2 FLGA Fault Flag A (Output): Active-low, open-drain output. A logic LOW state Indicates overcurrent or thermal shutdown conditions. Overcurrent conditions must last longer than tBDB in order to assert FLGA. The FLGA pin can be left floating; however, fault reporting information will be lost. 3 FLGB Fault Flag B (Output): Active-low, open-drain output. A logic LOW state indicates overcurrent or thermal shutdown conditions. Overcurrent conditions must last longer than tBDB in order to assert FLGB. The FLGB pin can be left floating; however, fault reporting information will be lost. 4 ENB Switch B Enable (Input): Logic-compatible enable input. Active-high (-1) or active-low (-2). 5 OUTB Switch B (Output). 6 GND Ground. 7 IN Input: Switch and logic supply input. 8 OUTA Switch A (Output). July 2009 2 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Absolute Maximum Ratings(1) Operating Ratings(2) P P Supply Voltage (V ).......................................–0.3V to +6V Supply Voltage (V )....................................+2.7V to +5.5V IN BINB Output Voltage (OUTA and OUTB) ................–0.3V to +6V Ambient Temperature (T )..........................–40°C to +85°C BAB All other pins voltages.....................................–0.3V to +6V Junction Temperature Range (T )............Internally Limited BJB Fault Flag Current (I )..............................................25mA Thermal Resistance BFLGB Output Current (I ).................................Internally Limited SOIC (θ ).......................................................160°C/W BOUTB BJAB Storage Temperature (T ).......................–65°C to +150 °C BSB ESD Rating(3) HBM.........................................................................3kV MM.........................................................................200V Lead Temperature (Soldering 10 sec).......................260°C Electrical Characteristics(4) V = 5V; T = 25°C, unless noted, bold values indicate –40°C ≤ T ≤ +85°C. IN A A Symbol Parameter Condition Min Typ Max Units MIC20X6A-1, V = V = 0V BENA B BENB B 0.75 5 µA (switch off), OUT = open MIC20X6A-2, V = V = 5V BENA B BENB B 0.75 20 µA (switch off), OUT = open I Supply Current BDDB MIC20X6A-1, V = V = 5V BENA B BENB 100 160 µA (switch on), OUT = open MIC20X6A-2, V = V = 0V BENA B BENB B 100 160 µA (switch on), OUT = open low-to-high transition 1.6 2.4 V V Enable Input Threshold BENB high-to-low transition 0.8 1.45 V V Enable Input Hysteresis 150 mV BEN_HYSTB IBENB Enable Input Current VBENB = 0V to 5V -1 0.01 1 µA C Enable Input Capacitance 1 pF BENB VBINB = 5.0V, IBOUTB = 500mA 100 140 mΩ R Switch On Resistance BDS(ON)B VBINB = 3.3V, IBOUTB = 500mA 90 170 mΩ MIC20X6A-1, VENX = 0V; 0.01 10 µA I Output Leakage Current MIC20X6A-2, VENX = VIN, (output off) BLEAKAGE MIC2076A, Thermal shutdown state 50 µA IBLIMITB Short-Circuit Output Current VBOUTB = 0V, enabled into short-circuit 0.5 0.7 1.25 A I Current-Limit Threshold Ramped load applied to output 1.0 1.25 A BLMT_TRSH V Undervoltage Lockout VBINB rising 2.2 2.45 2.7 V UVLO Threshold (UVLO) VBINB falling 2.0 2.25 2.5 V VUVHYST UVLO Hysteresis VBINB rising or VINB falling 200 mV RBFLGB Error Flag Output Resistance IBLB = 10mA 10 25 Ω I Error Flag Off Current V = V 10 µA BFLG_OFFB BFLAGB BINB tSC_RESP Short-Circuit Response Time sVhBOoUrTtB =ci r0cVu,i t applied to enabled switch 20 µs tBONB Output Turn-On Delay See Timing Diagrams, RL = 10Ω, CL = 1µF 1.3 5 ms tBRB Output Turn-On Rise Time See Timing Diagrams, RL = 10Ω, CL = 1µF 0.5 1.5 4.9 ms tBOFFB Output Turn-Off Delay See Timing Diagrams, RL = 10Ω, CL = 1µF 32 100 µs July 2009 3 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Symbol Parameter Condition Min Typ Max Units tBFB Output Turn-Off Fall Time See Timing Diagrams, RL = 10Ω, CL = 1µF 32 100 µs Overcurrent Flag Response t From short circuit to FLG pin assertion 1.5 3.5 7 ms D Delay TBJB increasing, each switch 140 °C T Overtemperature Threshold(5) TBJB decreasing, each switch 120 °C OVERTEMP P P TBJB increasing, both switches 160 °C TBJB decreasing, both switches 150 °C Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function properly outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. 4. Specification for packaged product only. 5. If there is a fault on one channel, that channel will shut down when the die reaches approximately 140°C. If the die reaches approximately 160°C, both channels will shut down, even if neither channel is in current limit. Test Circuit July 2009 4 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Timing Diagrams Output Rise and Fall Times Active-Low Switch Delay Times (MIC20x6A-2) Active-High Switch Delay Time (MIC20x6A-1) July 2009 5 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Typical Characteristics I R Output Rise Time DD_ON DS_ON vs. Temperature vs. Temperature vs. Temperature 180 160 5 160 140 5V 4 140 120 µA)110200 5V mΩ)100 E (ms)3 3V I (DD_ON 6800 3V R (DS_ON 6800 3V RISE TIM2 5V 40 40 1 20 20 0 0 0 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) I R Output Rise Time DD_ON DS_ON vs. VIN vs. VIN vs. VIN 180 200 5 160 180 -40°C 140 160 4 I (µA)DD_ON1168020000 85°C R (mΩ)DS_ON1116802400000 25°C 85°C RISE TIME (ms)23 85°C 25°C 40 25°C 40 -40°C 1 -40°C 20 20 0 0 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VIN (V) VIN (V) VIN (V) Short-Circuit Current-Limit Current-Limit Threshold Output Fall Time vs. Temperature vs. Temperature vs. Temperature 1000 1000 100 mA)800 5V mA)800 5V 3V 80 MIT (600 MIT (600 E (µs) 60 LI LI M 5V RENT 400 3V RENT-400 ALL TI 40 R R F U U C200 C200 20 3V 0 0 0 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) Short-Circuit Current-Limit Current-Limit Threshold Output Fall Time vs. V vs. V vs. V IN IN IN 1000 1000 100 -40°C 85°C mA)800 mA) 800 85°C 25°C 80 MIT (600 MIT ( 600 E (µs) 60 85°C T LI 25°C T-LI -40°C TIM REN400 REN 400 ALL 40 R R F U U C200 C 200 20 -40°C 25°C 0 0 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VIN (V) VIN (V) VIN (V) July 2009 6 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Typical Characteristics (continued) Enable Threshold Overcurrent Flag Delay I DD_OFF vs. Temperature vs. Temperature vs. Temperature 3.0 5 10 V)2.5 3V BLE THRESHOLD (112...050 53VV LAG DELAY (ms)234 5V I (µA)DD_OFF 468 5V ENA0.5 F1 2 3V 0.0 0 0 -40 -20 TE0MPE20RAT4U0RE6 (0°C)80 100 -40 -20 TE0MPE20RAT4U0RE6 (0°C)80 100 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) Enable Threshold Overcurrent Flag Delay I vs. V vs. V DD_OFF IN IN 5 5 vs. VIN 85°C 10.0 LD (V) 4 s)4 8.0 O m RESH 3 -40°C 25°C LAY (3 -40°C 25°C µA) 6.0 NABLE TH 12 FLAG DE12 I (DD_OFF 4.0 25°C85°C E 85°C 2.0 -40°C 0 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0.0 VIN (V) VIN (V) 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VIN (V) UVLO Threshold vs. Temperature 3.0 V)2.5 D ( OL2.0 H S RE1.5 H T O 1.0 L V U0.5 0.0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) July 2009 7 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Functional Characteristics July 2009 8 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Functional Characteristics (continued) July 2009 9 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Functional Characteristics (continued) July 2009 10 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Block Diagram MIC2026A/2076A Block Diagram Functional Description output if the die temperature reaches 140°C and the overheated channel is in current limit. The other channel Input and Output is not affected. If however, the die temperature exceeds 160°C, both channels will be shut off. IN is the power supply connection to the logic circuitry and the drain of the output MOSFET. OUT is the source The MIC2026A will automatically reset its output when of the output MOSFET. In a typical circuit, current flows the die temperature cools down to 120°C. The from IN to OUT toward the load when the switch is MIC2026A’s output and FLG signal will continue to cycle enabled. on and off until the device is disabled or the fault is removed. Figure 2 depicts typical timing. An important consideration in choosing a switch is whether it has “reverse voltage protection.” This is On the other hand, the MIC2076A’s output will be turned accomplished by eliminating the body diode during the off, and remain off until the MIC2076A is reset. This is fabrication process. Reverse voltage protection is often called latched output, that is, the output is “latched” important when the switch is disabled and a voltage is off and stays off. This is different from the MIC2026A’s presented to the OUT pin that is greater than the VIN pin output that will cycle on and off. The MIC2076A will voltage. The reverse voltage protection prevents current latch off the output when the MIC2076A is in current flow in the reverse path from OUT to IN. limiting and the switch goes in to thermal shutdown. Upon entering thermal shutdown, the output will be On other hand when the switch is enabled the switch is immediately latched off. The MIC2076A (latched output) bidirectional. In this case when a voltage is presented to can be reset by any of the following three methods: the OUT pin that is greater than the VIN voltage, current will flow from OUT to IN. 1. Remove the fault load 2. Toggle the EN (Enable) pin Thermal Shutdown 3. Cycle VIN (input power supply) Thermal shutdown is employed to protect the device from damage should the die temperature exceed safe Resetting the MIC2076A will return it to normal margins due mainly to short circuit faults. Each channel operation. employs its own thermal sensor. Thermal shutdown Depending on PCB layout, package, ambient shuts off the output MOSFET and asserts the FLG temperature, etc., it may take several hundred July 2009 11 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A milliseconds from the incidence of the fault to the output • Short-Circuit Applied to Enabled Output MOSFET being shut off. This time will be shortest in the When a heavy load or short-circuit is applied to an case of a dead short on the output. enabled switch, a large transient current may flow Power Dissipation until the current-limit circuitry responds. Once this occurs, the device limits current to the short-circuit The device’s junction temperature depends on several current limit specification. factors such as the load, PCB layout, ambient temperature, and package type. Equations that can be • Current-Limit Response used to calculate power dissipation of each channel and The MIC2026A/2076A current-limit response is often junction temperature are found below: called the foldback current-limit. The foldback PD = RDS(on) x IOUT2 current-limit is the current limit reached when the output current is increased slowly rather than Total power dissipation of the device will be the abruptly. An approximation of slowly is tens of summation of PD for both channels. To relate this to milliamps per second. The foldback current-limit is junction temperature, the following equation can be typical 200 mA higher than the short-circuit current- used: limit. When the foldback current-limit is reached, the TJ = PD × θJA + TA output current will abruptly decrease to the short- where: circuit current-limit. TJ = junction temperature Fault Flag TA = ambient temperature The FLG signal is an N-Channel open-drain MOSFET θJA = is the thermal resistance of the package output. FLG is asserted (active-low) when either an overcurrent or thermal shutdown condition occurs. In the Current Sensing and Limiting case of an overcurrent condition, FLG will be asserted The current-limit threshold is preset internally. The only after the flag response delay time, t , has elapsed. D preset level prevents damage to the device and external This ensures that FLG is asserted only upon valid load but still allows a minimum current of 500mA to be overcurrent conditions and that erroneous error reporting delivered to the load. is eliminated. For example, false overcurrent conditions The current-limit circuit senses a portion of the output can occur during hot plug events when a highly MOSFET switch current. The current-sense resistor capacitive load is connected and causes a high transient shown in the block diagram is a virtual and has no inrush current that exceeds the current-limit threshold for voltage drop. The reaction to an overcurrent condition up to 1ms. The FLG response delay time tD is typically varies with three scenarios: 3ms. • Switch Enabled into Short-Circuit Undervoltage Lockout If a switch is enabled into a heavy load or short- Undervoltage lockout (UVLO) prevents the output circuit, the switch immediately enters into a constant- MOSFET from turning on until VIN exceeds current mode, reducing the output voltage. The FLG approximately 2.45V. Undervoltage detection functions signal is asserted indicating an overcurrent condition. only when the switch is enabled. Figure 1. MIC2076A Fault Timing: Output Reset by Removing Load July 2009 12 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Figure 2. MIC2026A Fault Timing Application Information Universal Serial Bus (USB) Power Distribution The MIC2026A/2076A are ideally suited for USB Supply Filtering (Universal Serial Bus) power distribution applications. A 0.1µF to 1µF bypass capacitor positioned close to VIN The USB specification defines power distribution for and GND pins of the device is strongly recommended to USB host systems such as PCs and USB hubs. Hubs control supply transients. Without a bypass capacitor, an can either be self-powered or bus-powered (that is, output short may cause sufficient ringing on the input powered from the bus). Figure 5 shows a typical USB (from supply lead inductance) to damage internal control Host application that may be suited for mobile PC circuitry. applications employing USB. The requirement for USB host systems is that the port must supply a minimum of Printed Circuit Board Hot-Plug 500mA at an output voltage of 5V ±5%. In addition, the The MIC2026A/2076A are ideal inrush current-limiters output power delivered must be limited to below 25VA. for hot plug applications. Due to their integrated charge Upon an overcurrent condition, the host must also be pumps, the MIC2026A/2076A present a high impedance notified. To support hot-plug events, the hub must have when off and slowly become a low impedance as their a minimum of 120µF of bulk capacitance, preferably low integrated charge pumps turn on. This “soft-start” feature ESR electrolytic or tantalum. Please refer to Application effectively isolates power supplies from highly capacitive Note 17 for more details on designing compliant USB loads by reducing inrush current. Figure 3 shows how hub and host systems. the MIC2026A may be used in a card hot-plug For bus-powered hubs, USB requires that each application. downstream port be switched on or off under control by In cases of extremely large capacitive loads (>400µF), the host. Up to four downstream ports each capable of the length of the transient due to inrush current may supplying 100mA at 4.4V minimum are allowed. In exceed the delay provided by the integrated filter. Since addition, to reduce voltage droop on the upstream V , this inrush current exceeds the current-limit delay BUS soft-start is necessary. Although the hub can consume specification, FLG will be asserted during this time. To up to 500mA from the upstream bus, the hub must prevent the logic controller from responding to FLG consume only 100mA max at start-up, until it being asserted, an external RC filter, as shown in Figure enumerates with the host prior to requesting more 4, can be used to filter out transient FLG assertion. The power. The same requirements apply for bus-powered value of the RC time constant should be selected to peripherals that have no downstream ports. Figure 6 match the length of the transient, less tD(min) of the shows a bus-powered hub. MIC2026A/2076A. July 2009 13 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Figure 3. Hot-Plug Application Figure 4. Transient Filter July 2009 14 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Figure 5. USB Two-Port Host Application Figure 6. USB Two-Port Bus-Powered Hub July 2009 15 M9999-072309-B (408) 955-1690

Micrel, Inc. MIC2026A/2076A Package Information 8-Pin SOIC (M) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended forsurgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2009 Micrel, Incorporated. July 2009 16 M9999-072309-B (408) 955-1690

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: M icrel: MIC2026A-1YM TR MIC2076A-1YM TR M icrochip: MIC2026A-1YM MIC2026A-2YM MIC2076A-1YM MIC2076A-2YM MIC2076A-1YM-TR MIC2076A-2YM-TR