Typical Size 6,4 mm X 9,7 mm TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 3-V TO 6-V INPUT, 6-A OUTPUT TRACKING SYNCHRONOUS BUCK ™ PWM SWITCHER WITH INTEGRATED FETs (SWIFT ) FOR SEQUENCING FEATURES DESCRIPTION (cid:1) Power Up/Down Tracking For Sequencing (cid:1) 30-mΩ, 12-A Peak MOSFET Switches for High As a member of the SWIFT™ family of dc/dc regulators, Efficiency at 6-A Continuous Output Source the TPS54680 low-input voltage high-output current or Sink Current synchronous buck PWM converter integrates all (cid:1) required active components. Using the TRACKIN pin Wide PWM Frequency: with other regulators, simultaneous power up and down Fixed 350 kHz or Adjustable 280 kHz to are easily implemented. Included on the substrate with 700 kHz (cid:1) the listed features are a true, high performance, voltage Power Good and Enable error amplifier that enables maximum performance and (cid:1) Load Protected by Peak Current Limit and flexibility in choosing the output filter L and C Thermal Shutdown components; an under-voltage-lockout circuit to (cid:1) Integrated Solution Reduces Board Area and prevent start-up until the input voltage reaches 3 V; an Component Count internally or externally set slow-start circuit to limit inrush currents; and a power good output useful for APPLICATIONS processor/logic reset. (cid:1) Low-Voltage, High-Density Distributed Power The TPS54680 is available in a thermally enhanced Systems 28-pin TSSOP (PWP) PowerPAD™ package, which (cid:1) Point of Load Regulation for High eliminates bulky heatsinks. TI provides evaluation Performance DSPs, FPGAs, ASICs and modules and the SWIFT™ designer software tool to aid Microprocessors Requiring Sequencing in quickly achieving high-performance power supply (cid:1) Broadband, Networking and Optical designs to meet aggressive equipment development Communications Infrastructure cycles. SIMPLIFIED SCHEMATIC I/O Supply STARTUP TIMING v di Input VIN PH Core Supply e −1 V/ VfsI == 750 V0 kHz I/O g CORE TPS54680 olta BOOT ut V TRACKIN PGND utp O VBAIAGSNDVCSOEMNPSE − VO PWRGD(I/O) 5 V/div − d o o G er PWRGD(CORE) w o p t − Time − 500 µs/div Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD and SWIFT are trademarks of Texas Instruments. PRODUCTION DATA information is current as of publication date. Products Copyright © 2002 − 2005, Texas Instruments Incorporated conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ORDERING INFORMATION TA OUTPUT VOLTAGE PACKAGE PART NUMBER −40°C to 85°C 0.9 V to 3.3 V Plastic HTSSOP (PWP)(1)(2) TPS54680PWP (1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. (2) The PWP package is also available taped and reeled. Add an R suffix to the device type (i.e., TPS54680PWPR). See the application section of the data sheet for PowerPAD drawing and layout information. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1) TPS54680 UNIT VIN, ENA −0.3 V to 7 V RT −0.3 V to 6 V IInnppuutt vvoollttaaggee rraannggee, VVI VSENSE, TRACKIN −0.3 V to 4V VV BOOT −0.3 V to 17 V VBIAS, COMP, PWRGD −0.3 V to 7 V OOuuttppuutt vvoollttaaggee rraannggee, VVO PH −0.6 V to 10 V VV PH Internally Limited SSoouurrccee ccuurrrreenntt, IIO COMP, VBIAS 6 mA PH 12 A SSiinnkk ccuurrrreenntt,, IISS COMP 6 mmAA ENA, PWRGD 10 Voltage differential AGND to PGND ±0.3 V Operating virtual junction temperature range, TJ −40 to 125 °C Storage temperature, Tstg −65 to 150 °C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 300 °C (1) Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS MIN NOM MAX UNIT Input voltage, VI 3 6 V Operating junction temperature, TJ −40 125 °C DISSIPATION RATINGS(1)(2) PACKAGE THERMAL IMPEDANCE TA =25°C TA = 70°C TA = 85°C JUNCTION-TO-AMBIENT POWER RATING POWER RATING POWER RATING 28 Pin PWP with solder 18.2 °C/W 5.49 W(3) 3.02 W 2.20 W 28 Pin PWP without solder 40.5 °C/W 2.48 W 1.36 W 0.99 W (1) For more information on the PWP package, refer to TI technical brief, literature number SLMA002. (2) Test board conditions: 1. 3” x 3”, 4 layers, thickness: 0.062” 2. 1.5 oz. copper traces located on the top of the PCB 3. 1.5 oz. copper ground plane on the bottom of the PCB 4. 0.5 oz. copper ground planes on the 2 internal layers 5. 12 thermal vias (see “Recommended Land Pattern” in applications section of this data sheet) (3) Maximum power dissipation may be limited by over current protection. 2

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 ELECTRICAL CHARACTERISTICS over operating free-air temperature range unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SUPPLY VOLTAGE, VIN Input voltage range, VIN 3.0 6.0 V fs = 350 kHz, RT open, 11 15.8 PH pin open II(Q) QQuuiieesscceenntt ccuurrrreenntt fs = 500 kHz, RT = 100 kΩ, PH pin open 16 23.5 mmAA Shutdown, ENA = 0 V 1 1.4 UNDER VOLTAGE LOCK OUT Start threshold voltage, UVLO 2.95 3.0 V Stop threshold voltage, UVLO 2.70 2.80 V Hysteresis voltage, UVLO 0.14 0.16 V Rising and falling edge deglitch, UVLO(1) 2.5 µs BIAS VOLTAGE Output voltage, VBIAS I(VBIAS) = 0 2.70 2.80 2.90 V Output current, VBIAS (2) 100 µA CUMULATIVE REFERENCE Vref Accuracy 0.882 0.891 0.900 V REGULATION LLiinnee rreegguullaattiioonn((11))((33)) IL = 3 A, fs = 350 kHz, TJ = 85°C 0.04 %%//VV IL = 3 A, fs = 550 kHz, TJ = 85°C 0.04 LLooaadd rreegguullaattiioonn((11))((33)) IL = 0 A to 6 A, fs = 350 kHz, TJ = 85°C 0.03 %%//AA IL = 0 A to 6 A, fs = 550 kHz, TJ = 85°C 0.03 OSCILLATOR Internally set—free running frequency RT open 280 350 420 kHz RT = 180 kΩ (1% resistor to AGND) 252 280 308 EExxtteerrnnaallllyy sseett—ffrreeee rruunnnniinngg ffrreeqquueennccyy rraannggee RT = 100 kΩ (1% resistor to AGND) 460 500 540 kkHHzz RT = 68 kΩ (1% resistor to AGND) 663 700 762 Ramp valley(1) 0.75 V Ramp amplitude (peak-to-peak)(1) 1 V Minimum controllable on time(1) 200 ns Maximum duty cycle 90% (1) Specified by design (2) Static resistive loads only (3) Specified by the circuit used in Figure 9 3

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNIT ERROR AMPLIFIER Error amplifier open loop voltage gain 1 kΩ COMP to AGND(1) 90 110 dB Error amplifier unity gain bandwidth Parallel 10 kΩ, 160 pF COMP to AGND(1) 3 5 MHz Error amplifier common mode input voltage Powered by internal LDO(1) 0 VBIAS V range Input bias current, VSENSE VSENSE = Vref 60 250 nA Output voltage slew rate (symmetric), COMP 1.0 1.4 V/µs PWM COMPARATOR PWM comparator propagation delay time, PWM comparator input to PH pin (excluding 10-mV overdrive(1) 70 85 ns deadtime) ENABLE Enable threshold voltage, ENA 0.82 1.20 1.40 V Enable hysteresis voltage, ENA 0.03 V Falling edge deglitch, ENA(1) 2.5 µs Leakage current, ENA VI = 5.5 V 1 µA POWER GOOD Power good threshold voltage VSENSE falling 90 %Vref Power good hysteresis voltage(1) 3 %Vref Power good falling edge deglitch(1) 35 µs Output saturation voltage, PWRGD I(sink) = 2.5 mA 0.18 0.3 V Leakage current, PWRGD VI = 5.5 V 1 µA CURRENT LIMIT VI = 3 V Output shorted(1) 7.2 10 CCurrentt lliimiitt ttriip poiintt AA VI = 6 V Output shorted(1) 10 12 Current limit leading edge blanking time 100 ns Current limit total response time 200 ns THERMAL SHUTDOWN Thermal shutdown trip point(1) 135 150 165 °C Thermal shutdown hysteresis(1) 10 °C OUTPUT POWER MOSFETS rrDS(on) PPoowweerr MMOOSSFFEETT sswwiittcchheess VVII == 63 VV((44)) 2366 4675 mmΩΩ TRACKIN Input offset, TRACKIN VSENSE = TRACKIN = 1.25 V −1.5 1.5 mV Input voltage range, TRACKIN See Note 1 0 Vref V (1) Specified by design (2) Static resistive loads only (3) Specified by the circuit used in Figure 9 (4) Matched MOSFETs low-side rDS(on) production tested, high-side rDS(on) specified by design 4

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 PWP PACKAGE (TOP VIEW) AGND 1 28 RT VSENSE 2 27 ENA COMP 3 26 TRACKIN PWRGD 4 25 VBIAS BOOT 5 24 VIN PH 6 23 VIN PH 7 THERMAL 22 VIN PH 8 PAD 21 VIN PH 9 20 VIN PH 10 19 PGND PH 11 18 PGND PH 12 17 PGND PH 13 16 PGND PH 14 15 PGND TERMINAL FUNCTIONS TERMINAL DDEESSCCRRIIPPTTIIOONN NAME NO. AGND 1 Analog ground. Return for compensation network/output divider, slow-start capacitor, VBIAS capacitor, RT resistor. Connect PowerPAD to AGND. BOOT 5 Bootstrap output. 0.022-µF to 0.1-µF low-ESR capacitor connected from BOOT to PH generates floating drive for the high-side FET driver. COMP 3 Error amplifier output. Connect frequency compensation network from COMP to VSENSE ENA 27 Enable input. Logic high enables oscillator, PWM control and MOSFET driver circuits. Logic low disables operation and places device in low quiescent current state. PGND 15−19 Power ground. High current return for the low-side driver and power MOSFET. Connect PGND with large copper areas to the input and output supply returns, and negative terminals of the input and output capacitors. A single point connection to AGND is recommended. PH 6−14 Phase output. Junction of the internal high-side and low-side power MOSFETs, and output inductor. PWRGD 4 Power good open drain output. High when VSENSE ≥ 90% Vref, otherwise PWRGD is low. RT 28 Frequency setting resistor input. Connect a resistor from RT to AGND to set the switching frequency. TRACKIN 26 External reference input. High impedance input to internal reference/multiplexer and error amplifier circuits. VBIAS 25 Internal bias regulator output. Supplies regulated voltage to internal circuitry. Bypass VBIAS pin to AGND pin with a high quality, low-ESR 0.1-µF to 1.0-µF ceramic capacitor. VIN 20−24 Input supply for the power MOSFET switches and internal bias regulator. Bypass VIN pins to PGND pins close to device package with a high quality, low-ESR 10-µF ceramic capacitor. VSENSE 2 Error amplifier inverting input. Connect to output voltage through compensation network/output divider. 5

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 INTERNAL BLOCK DIAGRAM AGND VBIAS Enable Comparator VBIAS REG ENA Falling SHUTDOWN 1.2 V Edge ILIM VIN Deglitch Thermal Comparator VIN Hysteresis: 0.03 V 2.5 µs Shutdown Leading 150°C Edge VIN UVLO Blanking Comparator Falling 100 ns and VIN BOOT Rising 2.95 V Edge sense Fet Hysteresis: 0.16 V Deglitch 30 mΩ I/O 2.5 µs SS_DIS SHUTDOWN PH LOUT Core TRACKIN Multiplexer + − R Q Adaptive Dead-Time CO and Error S Control Logic Amplifier PWM Reference Comparator 25 ns Adaptive VIN Dead Time 30 mΩ OSC PGND Powergood Comparator PWRGD VSENSE Falling 0.90 Vref Edge TPS54680 Deglitch Hysteresis: 0.03 Vref SHUTDOWN 35 µs VSENSE COMP RT ADDITIONAL 6A SWIFT™ DEVICES, (REFER TO SLVS397 AND SLVS400) DEVICE OUTPUT VOLTAGE DEVICE OUTPUT VOLTAGE DEVICE OUTPUT VOLTAGE TPS54611 0.9 V TPS54614 1.8 V TPS54672 Active terminal TPS54612 1.2 V TPS54615 2.5 V TPS54610 Adjustable TPS54613 1.5 V TPS54616 3.3 V RELATED DC/DC PRODUCTS (cid:1) UCC3585—dc/dc controller (cid:1) TPS56300—dc/dc controller (cid:1) TPS759xx—7.5-A low dropout regulator (cid:1) PT6440 series—6-A plugin modules 6

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 TYPICAL CHARACTERISTICS DRAIN-SOURCE DRAIN-SOURCE INTERNALLY SET ON-STATE RESISTANCE ON-STATE RESISTANCE OSCILLATOR FREQUENCY vs vs vs JUNCTION TEMPERATURE JUNCTION TEMPERATURE JUNCTION TEMPERATURE ΩDrain Source On-State Reststance − m 1234560000000−40VIN = 3.03 V 25 IO = 6 8A5 125 ΩDrain Source On-State Reststance − m 1234560000000−40VIN = 5 0V 25IO = 6 A85 125 f − Internally Set Oscillator Frequency − kHz 234567555555000000−40 0 25 85 125 TJ − Junction Temperature − °C TJ − Junction Temperature − °C TJ − Junction Temperature − °C Figure 1 Figure 2 Figure 3 OSCEILXLTAETRONRA FLRLYE QSUEETNCY VOLTAGE REFERENCE DEVICE POWER LOSSES AT TJ = 125°C vs vs vs LOAD CURRENT JUNCTION TEMPERATURE JUNCTION TEMPERATURE y − kHz 800 0.895 4.55 TfsJ = = 7 10205 k°CHz nc 700 V 0.893 W 4 cillator Freque 560000 RT = 68 k e Reference − 0.891 wer Losses − 23..553 VI = 3.3 V Externally Set Os 340000 RRTT == 110800 kk − VoltagVref00..888879 Device Po 01..5512 VI = 5 V f − 200−40 0 25 85 125 0.885−40 0 25 85 125 00 1 2 3 4 5 6 7 8 TJ − Junction Temperature − °C TJ − Junction Temperature − °C IL − Load Current − A Figure 4 Figure 5 Figure 6 OUTPUT VOLTAGE REGULATION ERROR AMPLIFIER vs OPEN LOOP RESPONSE INPUT VOLTAGE 0.895 140 0 V TA = 85°C, RL = 10 kΩ, −20 on − 0.893 IO = 3 A 120 CTAL == 2156°0C pF, −40 utput Voltage Regulati 00..888991 fs = 550 kHz Gain − dB104680000 GaPinhase −−−−−1118642000000Phase − Degrees O 20 − O0.887 −160 V 0 −180 0.885 −20 −200 3 3.5 4 4.5 5 5.5 6 1 10 100 1 k 10 k 100 k 1 M 10 M VI − Input Voltage − V f − Frequency − Hz Figure 7 Figure 8 7

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 APPLICATION INFORMATION Figure 9 shows the schematic diagram for a typical board. To provide power up tracking, the enable of the I/O TPS54680 application. The TPS54680 (U1) can provide supply should be used. If the I/O enable is not used to greater than 6 A of output current at a nominal output power up, then devices with similar undervoltage lockout voltage of 1.8 V. For proper thermal performance, the thresholds need to be implemented to ensure power up exposed thermal PowerPAD underneath the integrated tracking. To ensure power down tracking, the enable pin circuit package must be soldered to the printed-circuit should be used. TPS54610 VOUT_I/O I/O Power Supply R1 U1 10 kΩ R2 28 1 10 RkΩ4 71.5 kΩ 2276 RETRNTAACKINVSCAEOGNMNSDPE 32 C1 R5 10R 3kΩ 25 VBIAS PWRGD4 470 pF 10 kΩ R7 C3 24 5 R6 C2 23 VIN BOOT 6 C5 C4 301 Ω 470 pF 9.76 kΩ 1 µF 22 VVIINN PPHH 7 0.047 µF 12 pF R8 21 VIN PH 8 9.76 kΩ 20 VIN PH 9 19 10 PGND PH 18 11 VOUT_CORE VIN PGND PH L1 C6 C7 1176 PGND PH 1132 R2.92 Ω 0.65 µH C8 C9 C10 10 µF 10 µF PGND PH 22 µF 22 µF 22 µF 15 PGND PH 14 C11 PwrPad 3300 pF Analog and Power Grounds are Tied at the Power Pad Under the Package of IC Figure 9. Application Circuit COMPONENT SELECTION at 1.8 V. R3, along with R7, R5, C1, C3, and C4 form the loop compensation network for the circuit. For this design, The values for the components used in this design a Type 3 topology is used. example were selected for low output ripple voltage and small PCB area. Additional design information is available at www.ti.com. OPERATING FREQUENCY INPUT FILTER In the application circuit, the 350 kHz operation is selected by leaving RT open. Connecting a 180kΩ to 68 kΩ resistor The input voltage is a nominal 5 Vdc. The input filter C6 is between RT (pin 28) and analog ground can be used to set a 10-µF ceramic capacitor (Taiyo Yuden). C7 also a 10-µF the switching frequency to 280kHz to 700 kHz. To ceramic capacitor (Taiyo Yuden) provides high frequency calculate the RT resistor, use the equation below: decoupling of the TPS54680 from the input supply and must be located as close as possible to the device. Ripple R(cid:1) 500kHz (cid:2)100[k(cid:1)] SwitchingFrequency (1) current is carried in both C6 and C7, and the return path to PGND must avoid the current circulating in the output OUTPUT FILTER capacitors C8, C9, and C10. The output filter is composed of a 0.65-µH inductor and 3 FEEDBACK CIRCUIT x 22-µF capacitor. The inductor is a low dc resistance (0.017 Ω) type, Pulse Engineering PA0227. The The values for these components have been selected to capacitors used are 22-µF, 6.3 V ceramic types with X5R provide low output ripple voltage. The resistor divider dielectric. The feedback loop is compensated so that the network of R3 and R8 sets the output voltage for the circuit unity gain frequency is approximately 75 kHz. 8

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 PCB LAYOUT decoupling capacitor, and the PGND pins of the TPS54680. Use a separate wide trace for the analog Figure 10 shows a generalized PCB layout guide for the ground signal path. This analog ground should be used for TPS54680. the voltage set point divider, timing resistor RT and bias capacitor grounds. Connect this trace directly to AGND The VIN pins should be connected together on the printed (pin 1). circuit board (PCB) and bypassed with a low ESR ceramic bypass capacitor. Care should be taken to minimize the The PH pins should be tied together and routed to the loop area formed by the bypass capacitor connections, the output inductor. Since the PH connection is the VIN pins, and the TPS54680 ground pins. The minimum switching node, inductor should be located very close recommended bypass capacitance is 10-µF ceramic with to the PH pins and the area of the PCB conductor a X5R or X7R dielectric and the optimum placement is minimized to prevent excessive capacitive coupling. closest to the VIN pins and the PGND pins. Connect the boot capacitor between the phase node The TPS54680 has two internal grounds (analog and and the BOOT pin as shown. Keep the boot capacitor power). Inside the TPS54680, the analog ground ties to all close to the IC and minimize the conductor trace of the noise sensitive signals, while the power ground ties lengths. to the noisier power signals. Noise injected between the Connect the output filter capacitor(s) as shown between two grounds can degrade the performance of the the VOUT trace and PGND. It is important to keep the TPS54680, particularly at higher output currents. Ground loop formed by the PH pins, Lout, Cout and PGND as noise on an analog ground plane can also cause problems small as practical. with some of the control and bias signals. For these reasons, separate analog and power ground traces are Place the compensation components from the VOUT recommended. There should be an area of ground one the trace to the VSENSE and COMP pins. Do not place top layer directly under the IC, with an exposed area for these components too close to the PH trace. Do to the connection to the PowerPAD. Use vias to connect this size of the IC package and the device pinout, they will ground area to any internal ground planes. Use additional have to be routed somewhat close, but maintain as vias at the ground side of the input and output filter much separation as possible while still keeping the capacitors as well. The AGND and PGND pins should be layout compact. tied to the PCB ground by connecting them to the ground area under the device as shown. The only components Connect the bias capacitor from the VBIAS pin to that should tie directly to the power ground plane are the analog ground using the isolated analog ground trace. input capacitors, the output capacitors, the input voltage If an RT resistor is used, connect it to this trace as well. 9

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 ANALOG GROUND TRACE AGND RT VSENSE ENA TRACKING VOLTAGE COMPENSATION COMP TRACKIN RESISTOR DIVIDER NETWORK BIAS CAPACITOR NETWORK PWRGD VBIAS BOOT CAPACITOR BOOT VIN EXPOSED PH POWERPAD VIN VOUT AREA PH VIN PH VIN VIN PH PH VIN PH PGND OUTPUT INDUCTOR PH PGND OUTPUT PH PGND FILTER CAPACITOR PH PGND INPUT INPUT PH PGND BYPASS BULK CAPACITOR FILTER TOPSIDE GROUND AREA VIA to Ground Plane Figure 10. TPS54680 PCB Layout 10

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 LAYOUT CONSIDERATIONS FOR THERMAL any area available must be used when 6 A or greater PERFORMANCE operation is desired. Connection from the exposed area of the PowerPAD to the analog ground plane layer must be For operation at full rated load current, the analog ground made using 0.013 inch diameter vias to avoid solder plane must provide an adequate heat dissipating area. A wicking through the vias. Eight vias must be in the 3-inch by 3-inch plane of 1 ounce copper is recommended, PowerPAD area with four additional vias located under the though not mandatory, depending on ambient temperature device package. The size of the vias under the package, and airflow. Most applications have larger areas of internal but not in the exposed thermal pad area, can be increased ground plane available, and the PowerPAD must be to 0.018. Additional vias beyond the twelve recommended connected to the largest area available. Additional areas that enhance thermal performance must be included in on the top or bottom layers also help dissipate heat, and areas not under the device package. Minimum Recommended Thermal Vias: 8 x 0.013 Diameter Inside 8 PL Ø0.0130 Powerpad Area 4 x 0.018 Diameter Under Device as Shown. Additional 0.018 Diameter Vias May Be Used if Top Side Analog Ground 4 PL Ø0.0180 Area Is Extended. Connect Pin 1 to Analog Ground Plane in This Area for Optimum Performance 0.0150 0.06 0.0339 0.0650 0.0500 0.3820 0.3478 0.0500 0.2090 0.0500 0.0256 0.0650 0.0339 Minimum Recommended Exposed Copper Area for Powerpad. 5mil 0.1700 Stencils May Require 10 Percent 0.1340 Larger Area Minimum Recommended Top Side Analog Ground Area 0.0630 0.0400 Figure 11. Recommended Land Pattern for 28-Pin PWP PowerPAD 11

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 PERFORMANCE GRAPHS EFFICIENCY LOAD REGULATION LINE REGULATION vs vs vs OUTPUT CURRENT OUTPUT CURRENT INPUT VOLTAGE 95 0.20 0.20 TA = 25°C, 90 VO = 1.8 V 0.15 VO = 0.9 V 0.15 FS = 700 kHz, 0.10 VO = 1.2 V 0.10 VO = 1.8 V Efficiency − % 77880505 VO = 1.2 V VO = 0.9 V Load Regulation − %−−000...0015050 TA = V25O° C= ,1.8 V Line Regulation − %−−000...0105005 IO = 0 AIO = 6 A VI = 3.3 V, VI = 3.3 V, 65 FS = 700 kHz, −0.15 FS = 700 kHz, −0.15 VO = 0.9 V, 1.8 V and 2.5 V VO = 0.9 V, 1.2 V and 1.8 V 60 −0.20 −0.20 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 3 3.5 4 4.5 5 5.5 6 IO − Output Current − A IO − Output Current − A VI − Input Voltage − V Figure 12 Figure 13 Figure 14 AMBIENT TEMPERATURE vs LOOP RESPONSE LOAD CURRENT v OUTPUT AND INPUT RIPPLE 5600 115800 112155 TfsJ = = 7 10205 k°CHz 00 mV/di v Gain − dB−−1234210000000 Gain Phase −−03691000263000Phase − Degrees°mbient Temperature − C 1056789555555 Safe Operating Area(1)VI = 3.3 VVI = 5 V Input Ripple − 1V/div Output Ripple − 20 mV/di −−−543000 VIfOSI === 7500 VA0,, kHz −−−11952000 A 3455 e Pin − 2 −60100 1 k 10 k 100 k 1 M−180 250 1 2 3 4 5 6 7 8 Phas t − Time − 1 µs/div f − Frequency − Hz IO − Output Current − A Figure 15 Figure 16 Figure 17 LOAD TRANSIENT RESPONSE STARTUP TIMING POWER DOWN TIMING − Output Voltage −100 mV/divVO VVIO = = 5 1 V.8, V Load Current 2A/div − Output Voltage −1 V/divVO VfsI == 750 V0 kHz PWRGPDW(IR/OG)DC(COOIR/OREE) Power Good − 5 V/div − Output Voltage −1 V/divVO CPIP/OWOWRRREGGDD((CI/OO)RE) Power Good − 5 V/div t − Time −20 µs/div t − Time − 500 µs/div t − Time −20 µs/div Figure 18 Figure 19 Figure 20 (1) Safe operating area is applicable to the test board conditions in the Dissipation Ratings 12

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 Figure 21 shows the schematic diagram for a power switch ensures the I/O voltage is not applied to the load supply tracking design using a TPS2034 high side power before U1 has enough bias voltage to operate and switch and a TPS54680 device. The TPS2034 power generate the core voltage. TPS2034 VOUT_I/O Distribution Switch R1 U1 10 kΩ R2 28 1 10 RkΩ4 71.5 kΩ 2276 RETRNTAACKINVSCAEOGNMNSDPE 32 C1 R5 10R 3kΩ 25 VBIAS PWRGD4 470 pF 10 kΩ R7 C3 24 5 R6 C2 23 VIN BOOT 6 C5 C4 301 Ω 470 pF 9.76 kΩ 1 µF 22 VVIINN PPHH 7 0.047 µF 12 pF R8 21 VIN PH 8 9.76 kΩ 20 VIN PH 9 19 10 PGND PH 18 11 VOUT_CORE VIN PGND PH L1 C6 C7 1176 PGND PH 1132 R2.92 Ω 0.65 µH C8 C9 C10 10 µF 10 µF PGND PH 22 µF 22 µF 22 µF 15 PGND PH 14 C11 PwrPad 3300 pF Analog and Power Grounds are Tied at the Power Pad Under the Package of IC Figure 21. 3.3-V Small Size, High Frequency Design 13

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 LOAD TRANSIENT RESPONSE v di V/ m 0 VI = 3.3 V, 10 VO = 1.8 V − e g a ut Volt A/div utp − 2 − O ent VO urr C ut p ut O − O t − Time −20 µs/div I Figure 22 EFFICIENCY LOAD REGULATION LINE REGULATION vs vs vs OUTPUT CURRENT OUTPUT CURRENT INPUT VOLTAGE 100 0.20 0.20 9905 VO = 1.8 V 0.15 VVTAIO = == 5 21 5V.8°,C V,, 0.15 VTFASO 2==5 7°1C0.80, Vk,Hz 85 % 0.10 FS = 700 kHz % 0.10 Efficiency − % 67785050 VO = 0.9 V VO = 1.2 V Load Regulation − −−000...0105005 Line Regulation − −−000...0100505 IO = 0 A IO = 6 A 60 VI = 5 V, 55 TFAS == 2750°0C k,Hz −0.15 −0.15 50 −0.20 −0.20 0.5 1 1.522.533.5 44.55 5.566.57 7.58 0 1 2 3 4 5 6 7 8 4 4.5 5 5.5 6 IO − Output Current − A IO − Output Current − A VI − Input Voltage − V Figure 23 Figure 24 Figure 25 AMBIENT TEMPERATURE vs LOOP RESPONSE LOAD CURRENT OUTPUT AND INPUT RIPPLE v Gain − dB−−12345621000000000 Gain Phase −−03691110002586300000 Phase − Degrees°bient Temperature − C 1110215678955555555 Safe Operating Area(1)VI Tf=s J 3= =. 37 1 0V2V05 I k°=CH 5z V Input Ripple − 100 mV/didiv Output Ripple − 20 mV/div −−4300 VIOI == 03 .3A ,V, −−19200 Am 45 n − 2 V/ −50 fS = 700 kHz −150 35 Pi e −60 −180 25 as 100 1 k 10 k 100 k 1 M 0 1 2 3 4 5 6 7 8 Ph t − Time − 1 µs/div f − Frequency − Hz IO − Output Current − A Figure 26 Figure 27 Figure 28 14

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 SLOW-START TIMING SLOW-START TIMING VI = 5 V, VI = 5 V, 0.04 µF 0.04 µF Slow-start Cap Slow-start Cap Output Voltage − 0,5 V/div Output Voltage − 0.5 V/div 4.0 ms/div 4.0 ms/div Figure 29 Figure 30 15

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 DETAILED DESCRIPTION VOLTAGE REFERENCE The voltage reference system produces a precise V UNDERVOLTAGE LOCK OUT (UVLO) ref signal by scaling the output of a temperature stable The TPS54680 incorporates an under voltage lockout bandgap circuit. During manufacture, the bandgap and circuit to keep the device disabled when the input voltage scaling circuits are trimmed to produce 0.891 V at the (VIN) is insufficient. During power up, internal circuits are output of the error amplifier, with the amplifier connected held inactive until VIN exceeds the nominal UVLO as a voltage follower. The trim procedure adds to the high threshold voltage of 2.95 V. Once the UVLO start threshold precision regulation of the TPS54680, since it cancels is reached, device start-up begins. The device operates offset errors in the scale and error amplifier circuits. until VIN falls below the nominal UVLO stop threshold of OSCILLATOR AND PWM RAMP 2.8 V. Hysteresis in the UVLO comparator, and a 2.5-µs rising and falling edge deglitch circuit reduce the likelihood The oscillator frequency is set internally to 350 kHz. If a of shutting the device down due to noise on VIN. different frequency of operation is required for the application, the oscillator frequency can be externally TRACKIN/INTERNAL SLOW-START adjusted from 280 to 700 kHz by connecting a resistor The internal slow-start circuit provides start-up slope between the RT pin and AGND. The switching frequency control of the output voltage. The nominal internal is approximated by the following equation, where R is the slow-start rate is 25 V/ms. When the voltage on TRACKIN resistance from RT to AGND: rises faster than the internal slope or is present when SwitchingFrequency(cid:1)100k(cid:1)(cid:2)500[kHz] (2) device operation is enabled, the output rises at the internal R rate. If the reference voltage on TRACKIN rises more SWITCHING FREQUENCY RT PIN slowly, then the output rises at about the same rate as TRACKIN. 350 kHz, internally set Float Externally set 280 kHz to 700 kHz R = 180 kΩ to 68 kΩ Once the voltage on the TRACKIN pin is greater than the internal reference of 0.891 V, the multiplexer switches the ERROR AMPLIFIER noninverting node to the high precision reference. The high performance, wide bandwidth, voltage error amplifier sets the TPS54680 apart from most dc/dc ENABLE (ENA) converters. The user is given the flexibility to use a wide The enable pin, ENA, provides a digital control enable or range of output L and C filter components to suit the disable (shut down) for the TPS54680. An input voltage of particular application needs. Type 2 or type 3 1.4 V or greater ensures that the TPS54680 is enabled. An compensation can be employed using external input of 0.82 V or less ensures that device operation is compensation components. disabled. These are not standard logic thresholds, even PWM CONTROL though they are compatible with TTL outputs. Signals from the error amplifier output, oscillator, and When ENA is low, the oscillator, slow-start, PWM control current limit circuit are processed by the PWM control and MOSFET drivers are disabled and held in an initial logic. Referring to the internal block diagram, the control state ready for device start-up. On an ENA transition from logic includes the PWM comparator, OR gate, PWM latch, low to high, device start-up begins with the output starting and portions of the adaptive dead-time and control logic from 0 V. block. During steady-state operation below the current limit threshold, the PWM comparator output and oscillator VBIAS REGULATOR (VBIAS) pulse train alternately reset and set the PWM latch. Once the PWM latch is reset, the low-side FET remains on for a The VBIAS regulator provides internal analog and digital minimum duration set by the oscillator pulse width. During blocks with a stable supply voltage over variations in this period, the PWM ramp discharges rapidly to its valley junction temperature and input voltage. A high quality, voltage. When the ramp begins to charge back up, the low-ESR, ceramic bypass capacitor is required on the low-side FET turns off and high-side FET turns on. As the VBIAS pin. X7R or X5R grade dielectrics are PWM ramp voltage exceeds the error amplifier output recommended because their values are more stable over voltage, the PWM comparator resets the latch, thus temperature. The bypass capacitor must be placed close turning off the high-side FET and turning on the low-side to the VBIAS pin and returned to AGND. FET. The low-side FET remains on until the next oscillator External loading on VBIAS is allowed, with the caution that pulse discharges the PWM ramp. internal circuits require a minimum VBIAS of 2.70V, and During transient conditions, the error amplifier output external loads on VBIAS with ac or digital switching noise could be below the PWM ramp valley voltage or above the may degrade performance. The VBIAS pin may be useful PWM peak voltage. If the error amplifier is high, the PWM as a reference voltage for external circuits. latch is never reset, and the high-side FET remains on until 16

TPS54680 www.ti.com SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005 the oscillator pulse signals the control logic to turn the OVERCURRENT PROTECTION high-side FET off and the low-side FET on. The device The cycle-by-cycle current limiting is achieved by sensing operates at its maximum duty cycle until the output voltage the current flowing through the high-side MOSFET and rises to the regulation set-point, setting VSENSE to comparing this signal to a preset overcurrent threshold. approximately the same voltage as VREF. If the error The high side MOSFET is turned off within 200 ns of amplifier output is low, the PWM latch is continually reset reaching the current limit threshold. A 100-ns leading edge and the high-side FET does not turn on. The low-side FET blanking circuit prevents the current limit from false remains on until the VSENSE voltage decreases to a tripping. Current limit detection occurs only when current range that allows the PWM comparator to change states. flows from VIN to PH when sourcing current to the output The TPS54680 is capable of sinking current continuously filter. Load protection during current sink operation is until the output reaches the regulation set-point. provided by thermal shutdown. If the current limit comparator trips for longer than 100 ns, THERMAL SHUTDOWN the PWM latch resets before the PWM ramp exceeds the error amplifier output. The high-side FET turns off and The device uses the thermal shutdown to turn off the power low-side FET turns on to decrease the energy in the output MOSFETs and disable the controller if the junction inductor and consequently the output current. This temperature exceeds 150°C. The device is released from process is repeated each cycle in which the current limit shutdown automatically when the junction temperature comparator is tripped. decreases to 10°C below the thermal shutdown trip point, and starts up under control of the slow-start circuit. DEAD-TIME CONTROL AND MOSFET Thermal shutdown provides protection when an overload DRIVERS condition is sustained for several milliseconds. With a persistent fault condition, the device cycles continuously; Adaptive dead-time control prevents shoot-through starting up by control of the soft-start circuit, heating up due current from flowing in both N-channel power MOSFETs to the fault condition, and then shutting down upon during the switching transitions by actively controlling the reaching the thermal shutdown trip point. This sequence turnon times of the MOSFET drivers. The high-side driver repeats until the fault condition is removed. does not turn on until the voltage at the gate of the low-side FET is below 2 V. While the low-side driver does not turn POWER-GOOD (PWRGD) on until the voltage at the gate of the high-side MOSFET The power good circuit monitors for under voltage is below 2 V. conditions on VSENSE. If the voltage on VSENSE is 10% The high-side and low-side drivers are designed with below the reference voltage, the open-drain PWRGD 300-mA source and sink capability to quickly drive the output is pulled low. PWRGD is also pulled low if VIN is power MOSFETs gates. The low-side driver is supplied less than the UVLO threshold or ENA is low, or a thermal from VIN, while the high-side drive is supplied from the shutdown occurs. When VIN ≥ UVLO threshold, ENA ≥ BOOT pin. A bootstrap circuit uses an external BOOT enable threshold, and VSENSE > 90% of V , the open ref capacitor and an internal 2.5-Ω bootstrap switch drain output of the PWRGD pin is high. A hysteresis connected between the VIN and BOOT pins. The voltage equal to 3% of V and a 35 µs falling edge deglitch ref integrated bootstrap switch improves drive efficiency and circuit prevent tripping of the power good comparator due reduces external component count. to high frequency noise. 17

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) TPS54680PWP ACTIVE HTSSOP PWP 28 50 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 TPS54680 & no Sb/Br) TPS54680PWPR ACTIVE HTSSOP PWP 28 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 TPS54680 & no Sb/Br) TPS54680PWPRG4 ACTIVE HTSSOP PWP 28 2000 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 TPS54680 & no Sb/Br) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF TPS54680 : •Enhanced Product: TPS54680-EP NOTE: Qualified Version Definitions: •Enhanced Product - Supports Defense, Aerospace and Medical Applications Addendum-Page 2

PACKAGE MATERIALS INFORMATION www.ti.com 12-Feb-2019 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) TPS54680PWPR HTSSOP PWP 28 2000 330.0 16.4 6.9 10.2 1.8 12.0 16.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 12-Feb-2019 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) TPS54680PWPR HTSSOP PWP 28 2000 350.0 350.0 43.0 PackMaterials-Page2

GENERIC PACKAGE VIEW PWP 28 PowerPADTM TSSOP - 1.2 mm max height 4.4 x 9.7, 0.65 mm pitch SMALL OUTLINE PACKAGE Images above are just a representation of the package family, actual package may vary. Refer to the product data sheet for package details. 4224765/A www.ti.com

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