Manufacturer Part NumberTPS5401
DescriptionThe TPS5401 device is a 42-V, 0
ManufacturerTexas Instruments
TPS5401 datasheet

Specifications of TPS5401

Switching Frequency(max)(khz)2500Switch Current Limit(typ)(a)0.94
TopologyBuckOperating Temperature Range(c)-40 to 150
Pin/package10MSOP-PowerPADDuty Cycle(max)(%)98
Regulated Outputs(#)1  
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0.5-A, 42-V Input, Step-Down SWIFT™ Converter
3.5-V to 42-V Input Voltage Range
200-mΩ High-Side MOSFET
High Efficiency at Light Loads With a
Pulse-Skipping Eco-mode™ Control Scheme
116-mA Operating Quiescent Current
1.3-mA Shutdown Current
100-kHz to 2.5-MHz Switching Frequency
Synchronizes to External Clock
Adjustable Slow Start/Sequencing
UV and OV Power-Good Output
Adjustable UVLO Voltage and Hysteresis
The TPS5401 device is a 42-V, 0.5-A, step-down regulator with an integrated high-side MOSFET. Current-mode
control provides simple external compensation and flexible component selection. A low-ripple pulse-skip mode
reduces the supply current to 116 mA when outputting regulated voltage with no load. Using the enable pin,
shutdown supply current is reduced to 1.3 mA when the enable pin is low.
Undervoltage lockout is internally set at 2.5 V, but can be increased using the enable pin. The output voltage
start-up ramp is controlled by the slow-start pin that can also be configured for sequencing/tracking. An
open-drain power-good signal indicates the output is within 94% to 107% of its nominal voltage.
A wide switching-frequency range allows efficiency and external component size optimization. Frequency
foldback and thermal shutdown protect the part during an overload condition.
The TPS5401 is available in a 10-pin thermally enhanced MSOP PowerPAD package.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Eco-mode, PowerPAD, SwitcherPro, SWIFT are trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Check for Samples:
0.8-V ±3.5% Internal Voltage Reference
MSOP10 With PowerPAD™ Package
Supported by SwitcherPro™ Software Tool
For SWIFT™ Power Products Documentation,
See the TI Web Site at
12-V and 24-V Industrial and Commercial
Low-Power Systems
V = 12 V
= 5 V
= 700 kHz
Load Current – A
Copyright © 2010, Texas Instruments Incorporated

TPS5401 Summary of contents

  • Page 1

    ... Adjustable UVLO Voltage and Hysteresis DESCRIPTION The TPS5401 device is a 42-V, 0.5-A, step-down regulator with an integrated high-side MOSFET. Current-mode control provides simple external compensation and flexible component selection. A low-ripple pulse-skip mode reduces the supply current to 116 mA when outputting regulated voltage with no load. Using the enable pin, shutdown supply current is reduced to 1 ...

  • Page 2

    ... For the most-current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI Web site at (2) The DGQ package is also available taped and reeled. Add an R suffix to the device type (i.e., TPS5401DGQR). ABSOLUTE MAXIMUM RATINGS Over operating temperature range (unless otherwise noted). ...

  • Page 3

    ... I < COMP COMP V = 0.4 V VSENSE V = 0.8 V VSENSE 100 mV overdrive COMP 25° Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 TPS5401 UNIT MSOP (10 PINS) 44.6 °C/W 1.4 °C/W 22.8 °C/W 25.6 °C/W MIN TYP MAX UNIT 3 2 ...

  • Page 4

    ... VSENSE V falling VSENSE 5.5 V, 25°C VSENSE ref PWRGD mA, V < 0.77 V PWRGD VSENSE V < 0 100 mA PWRGD PWRGD Product Folder Link(s): TPS5401 MIN TYP MAX UNIT 100 2500 kHz 450 581 720 kHz 300 2200 kHz 40 ns 1.9 2.2 V 0.5 0.7 ...

  • Page 5

    ... Inverting node of the transconductance (gm) error amplifier. Copyright © 2010, Texas Instruments Incorporated DEVICE INFORMATION MSOP10 (TOP VIEW Thermal Pad 3 8 (11 PIN FUNCTIONS DESCRIPTION Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 PH GND COMP VSENSE PWRGD Submit Documentation Feedback 5 ...

  • Page 6

    ... Frequency Shift Maximum Clamp Oscillator with PLL 5 RT/CLK Product Folder Link(s): TPS5401 VIN 2 Thermal UVLO Shutdown Shutdown Shutdown Logic Boot Charge Boot Current UVLO Sense BOOT Thermal 11 Pad GND 9 TPS5401 Block Diagram Copyright © 2010, Texas Instruments Incorporated ...

  • Page 7

    ... SWITCHING FREQUENCY vs RT/CLK RESISTANCE 500 25°C J 400 300 200 100 0 125 150 175 200 200 300 Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 IN – 100 125 T – Junction Temperature – °C J Figure 2. W – ...

  • Page 8

    ... SS/TR CHARGE CURRENT vs JUNCTION TEMPERATURE – –1.5 –2 –2.5 –3 75 100 125 150 –50 – Product Folder Link(s): TPS5401 – 100 125 T – Junction Temperature – °C J Figure 8. = Threshold + 100 ...

  • Page 9

    ... VIN SUPPLY CURRENT vs INPUT VOLTAGE 140 130 120 110 100 100 125 150 Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 SWITCHING FREQUENCY vs VSENSE 0.2 0.4 0.6 V – Voltage at VSENSE Pin – V VSENSE Figure 14 – Input Voltage – Figure 16 ...

  • Page 10

    ... SS/TR TO VSENSE OFFSET vs TEMPERATURE 0.2 V SS/ –50 –25 800 1000 Product Folder Link(s): TPS5401 V Rising VSENSE V Falling VSENSE Rising V Falling VSENSE 100 125 150 T – Junction Temperature – °C J Figure 20. ...

  • Page 11

    ... BOOT pin to the PH pin. The boot capacitor voltage is monitored by a UVLO circuit and turns the high-side MOSFET off when the boot voltage falls below a preset threshold. The TPS5401 can operate at high duty cycles because of the boot UVLO. The output voltage can be stepped down to as low as the 0.8-V reference. ...

  • Page 12

    ... The TPS5401 operates in a pulse-skip Eco-mode control scheme at light load currents to improve efficiency by reducing switching and gate-drive losses. The TPS5401 is designed so that if the output voltage is within regulation and the peak switch current at the end of any switching cycle is below the pulse-skipping current threshold, the device enters the Eco-mode control scheme ...

  • Page 13

    ... A ceramic capacitor with an X7R or X5R grade dielectric with a voltage rating higher is recommended because of the stable characteristics over temperature and voltage. To improve dropout, the TPS5401 is designed to operate at 100% duty cycle as long as the BOOT-to-PH pin voltage is greater than 2.1 V. When the voltage from BOOT to PH drops below 2.1 V, the high-side MOSFET is turned off using an UVLO circuit, which allows the low-side diode to conduct and refresh the charge on the BOOT capacitor ...

  • Page 14

    ... Figure 26. 3.3-V Start/Stop Voltage Error Amplifier The TPS5401 has a transconductance amplifier as the error amplifier. The error amplifier compares the VSENSE voltage to the lower of the SS/TR pin voltage or the internal 0.8-V voltage reference. The transconductance (gm) of the error amplifier is 97 mA/V during normal operation. During the slow-start operation, the transconductance is a fraction of the normal operating gm ...

  • Page 15

    ... At power up, the TPS5401 does not start switching until the slow-start pin is discharged to less than ensure a proper power up; see Figure Also, during normal operation, the TPS5401 stops switching and SS/TR must be discharged when the VIN UVLO is exceeded, the EN pin is pulled below 1. thermal shutdown event occurs. ...

  • Page 16

    ... The sequential method can be implemented using an open-drain output of a power-on-reset pin of another device. The sequential method is illustrated in to the EN pin on the TPS5401, which enables the second power supply once the primary supply reaches regulation. If needed, a 1-nF ceramic capacitor on the EN pin of the second power supply provides a 1-ms start-up delay ...

  • Page 17

    ... Copyright © 2010, Texas Instruments Incorporated TPS5401 EN V EN1 SS /TR PWRGD Figure 31. Sequential Start-Up Using EN and V Figure 33. Ratiometric Start-Up Using Coupled Equation 4. Figure 33 shows the results of Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 V PWRGD1 V OUT1 V OUT2 PWRGD , V EN1 EN2 V OUT1 V OUT2 ...

  • Page 18

    ... OUT1 are included as variables in the equations. ss voltage is slightly greater than the V OUT2 Equation 5 through Equation 7 is slightly lower than V OUT2 is greater than the value calculated in Product Folder Link(s): TPS5401 V OUT1 V OUT2 R3 and V OUT1 ss Figure 37 shows the result when voltage when V OUT1 for Δ ...

  • Page 19

    ... Figure 35. Ratiometric Start-Up With V V out1 Copyright © 2010, Texas Instruments Incorporated V OUT1 V OUT2 Leading Figure 36. Ratiometric Start-Up With V out2 OUT1 Figure 37. Simultaneous Start-Up Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 OUT1 V OUT2 Leading out1 V out2 V OUT2 Submit Documentation Feedback (7) (8) 19 ...

  • Page 20

    ... DETAILED DESCRIPTION (continued) Constant Switching Frequency and Timing Resistor (RT/CLK Pin) The switching frequency of the TPS5401 is adjustable over a wide range from approximately 100 kHz to 2500 kHz by placing a resistor on the RT/CLK pin. The RT/CLK pin voltage is typically 0.5 V and must have a resistor to ground to set the switching frequency. To determine the timing resistance for a given switching frequency, use ...

  • Page 21

    ... Figure 39. Synchronizing to a System Clock Copyright © 2010, Texas Instruments Incorporated Skip Shift – Input Voltage – TPS5401 RT/CLK PLL Clock R T Source Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 OUT 40 Figure 39. The square-wave Submit Documentation Feedback 21 ...

  • Page 22

    ... SS/TR pin. Current-Mode Compensation Design To simplify design efforts using the TPS5401, the typical designs for common applications are listed in For designs using ceramic output capacitors, proper derating of ceramic output capacitance is recommended when doing the stability analysis. This is because the actual ceramic capacitance drops considerably from the nominal value when the applied voltage increases ...

  • Page 23

    ... In this situation, a linear regulator is not suitable due to its very low efficiency at high input voltage. Figure 40 shows a typical TPS5401 application schematic for this requirement. The input range is set to 7 With such a wide input voltage range, an inexpensive transformer with high dc resistance can be used to save total cost. ...

  • Page 24

    ... Input Capacitor The TPS5401 requires a high-quality ceramic, type X5R or X7R, input decoupling capacitor with at least effective capacitance, and in some applications a bulk capacitance. The effective capacitance includes any dc bias effects. The voltage rating of the input capacitor must be greater than the maximum input voltage. The capacitor must also have a ripple-current rating greater than the maximum input-current ripple of the TPS5401 ...

  • Page 25

    ... For designs using low-ESR output capacitors such as ceramics, a value as high as K When using higher-ESR output capacitors, K part of the PWM control system, the TPS5401 requires ripple current that is always greater than 30 mA for dependable operation wide-input voltage regulator best to choose an inductor ripple current on the larger side ...

  • Page 26

    ... L(RMS) Equation 20 shows the minimum output capacitance necessary ESR /ΔI . For this example, the transient load response is OUT OUT Product Folder Link(s): TPS5401 (17) (18) (19) = 0.565 A. The inductor used is L(peak) (20) OUT Equation 21 is used to calculate the is the value of the OUT Copyright © ...

  • Page 27

    ... OUT Catch Diode The TPS5401 requires an external catch diode between the PH pin and GND. The selected diode must have a reverse voltage rating equal to or greater than V the maximum inductor current. The diode should also have a low forward voltage. Schottky diodes are typically a good choice for the catch diode, due to their low forward voltage ...

  • Page 28

    ... The undervoltage lockout (UVLO) can be adjusted using an external voltage divider on the EN pin of the TPS5401. The UVLO has two thresholds, one for power up when the input voltage is rising and one for power down or brown outs when the input voltage is falling. The supply should turn on and start switching once the input voltage increases above power-up threshold (enabled) ...

  • Page 29

    ... ESR OUT A type 2A compensation scheme is recommended for the TPS5401 compensation components are chosen to set the desired loop crossover frequency and phase margin for output filter components. The type 2A compensation has the following characteristics gain, a low-frequency pole, and a mid-frequency zero / pole pair. ...

  • Page 30

    ... P The first step is to choose the closed-loop crossover frequency f frequency could be less than 1/10 of the minimum operating frequency. But for the TPS5401 recommended that the maximum closed-loop crossover frequency be not greater than 40 kHz. For this example, we choose 15-kHz crossover frequency. Next, by definition, the magnitude of the loop gain at the crossover frequency ...

  • Page 31

    ... Figure 47. Input Ripple, CCM 100 0.1 Figure 49. Efficiency vs Load Current Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 Time = 1 usec / div Time = 1 µsec / div 7 0.2 0.3 0.4 0 Output Current - A OUT Submit Documentation Feedback 31 ...

  • Page 32

    ... Figure 51. Overall Loop-Frequency Response 0.10 0. 0.06 0.04 0.02 0.00 −0.02 −0.04 −0.06 −0.08 −0.10 0.4 0.5 5 Figure 53. Regulation vs Input Voltage Product Folder Link(s): TPS5401 Phase Gain 1000 10000 100000 1000000 Frequency - 0.25 A OUT Input Voltage - V IN Copyright © 2010, Texas Instruments Incorporated ...

  • Page 33

    ... Copyright © 2010, Texas Instruments Incorporated ), switching loss (P con - 9 f ´ SW SUP , the junction temperature T can be estimated Product Folder Link(s): TPS5401 TPS5401 SLVSAB0 – DECEMBER 2010 ), gate-drive loss (P ), and sw GD (36) (37) (38) (39) (40) Equation 41. (41) Equation 42. ...

  • Page 34

    ... Capacitor BOOT PH VIN GND EN COMP SS/TR VSENSE PWRGD RT/CLK Frequency Set Resistor Figure 54. PCB Layout Example Product Folder Link(s): TPS5401 Output Inductor Catch Diode Compensation Resistor Network Divider Thermal VIA Signal VIA 2 Figure 40 is 0.55 in Copyright © 2010, Texas Instruments Incorporated ...

  • Page 35

    ... TPS5401DGQ ACTIVE MSOP- PowerPAD TPS5401DGQR ACTIVE MSOP- PowerPAD TPS5401DGQT ACTIVE MSOP- PowerPAD (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. ...

  • Page 36

    ... TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Type Drawing TPS5401DGQR MSOP- DGQ Power PAD TPS5401DGQT MSOP- DGQ Power PAD PACKAGE MATERIALS INFORMATION Pins SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 10 2500 330.0 12.4 5.3 10 250 180.0 12.4 5.3 Pack Materials-Page 1 ...

  • Page 37

    ... Device Package Type TPS5401DGQR MSOP-PowerPAD TPS5401DGQT MSOP-PowerPAD PACKAGE MATERIALS INFORMATION Package Drawing Pins SPQ Length (mm) DGQ 10 2500 DGQ 10 250 Pack Materials-Page 2 9-Sep-2011 Width (mm) Height (mm) 346.0 346.0 35.0 203.0 203.0 35.0 ...

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    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...