Texas Instruments TPS51123 User Manual Download Page 2

1 Introduction

The TPS51123 is a cost effective, dual-synchronous buck controller targeted for notebook system power supply 
solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The TPS51123 supports 
high-efficiency, fast transient response and provides a combined power-good signal. Out-of-Audio

 mode light-

load operation enables low acoustic noise at much higher efficiency than conventional forced PWM operation. 
Adaptive on-time D-CAP

 control provides convenient and efficient operation. The device operates with supply 

input voltages ranging from 5.5 V to 28 V and supports output voltages from 2 V to 5.5 V.

The TPS51123EVM evaluation module is a high-efficiency, dual synchronous buck converter providing 5 V at 8 A 
and 3.3 V at 8 A from a 8-V to 25-V input.

Trademarks

Out-of-Audio

 and D-CAP

 are trademarks of Texas Instruments.

All trademarks are the property of their respective owners.

2 Performance Specification Summary

Table 2-1

 gives the EVM performance specifications and qualifications.

Table 2-1. Performance Specification Summary

SPECIFICATION

TEST CONDITIONS

MIN

TYP

MAX

UNITS

V

IN

Input voltage range

Voltage applied to VBAT

8

25

V

CHANNEL1

V

OUT

Output voltage

5

V

f

Operating frequency

V

TONSEL

 = V

VREF

, V

VIN

 = 12 V, I

OUT

 = 6 A

245

kHz

I

OUT

Output current

8 V ≤ V

VIN

 ≤ 25 V

8

A

I

OC

Overcurrent limit

V

VIN

 = 12 V

10

CHANNEL2

V

OUT

Output voltage

3.3

V

f

Operating frequency

V

TONSEL

 = V

VREF

, V

VIN

 = 12 V, I

OUT

 = 6 A

305

kHz

I

OUT

Output current

8 V ≤ V

VIN

 ≤ 25 V

8

A

I

OC

Overcurrent limit

V

VIN

 = 12 V

10

Introduction

www.ti.com

2

TPS51123 Buck Controller Evaluation Module User's Guide

SLUU340A – FEBRUARY 2009 – REVISED JANUARY 2022

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Copyright © 2022 Texas Instruments Incorporated

Summary of Contents for TPS51123

Page 1: ...3 Schematic 3 4 Test Setup and Results 4 5 Configuration 6 6 Physical Layouts 7 7 List of Materials 11 8 References 12 9 Revision History 12 www ti com Table of Contents SLUU340A FEBRUARY 2009 REVISED...

Page 2: ...at 8 A from a 8 V to 25 V input Trademarks Out of Audio and D CAP are trademarks of Texas Instruments All trademarks are the property of their respective owners 2 Performance Specification Summary Tab...

Page 3: ...PS51123 EVM Schematic Diagram www ti com Schematic SLUU340A FEBRUARY 2009 REVISED JANUARY 2022 Submit Document Feedback TPS51123 Buck Controller Evaluation Module User s Guide 3 Copyright 2022 Texas I...

Page 4: ...Figure 4 1 Equipment Setup for TPS51123EVM Board 4 2 Test Procedure 1 Ensure the switches SW4 ENC and SW3 EN0 are in the OFF position 2 Ensure the shunt jumper for JP1 is set to 5 pin to 6 pin Med1 a...

Page 5: ...e 4 3 3 3 V Start Up Waveforms 4 4 Transient Performance Figure 4 4 5 V Load Transient Response Figure 4 5 3 3 V Load Transient Response www ti com Test Setup and Results SLUU340A FEBRUARY 2009 REVISE...

Page 6: ...ION SWITCHING FREQUENCY kHz CH1 CH2 GND SLOW 200 250 VREF MED1 245 305 VREG3 MED2 300 375 VREG5 FAST 365 460 5 2 Operation Mode Selection Operation mode can be set by the SKIPSEL pin using JP2 on the...

Page 7: ...re 6 1 the bottom layer Figure 6 2 and inner layer views Figure 6 3 and Figure 6 4 of the EVM Figure 6 1 Top Layer Routing www ti com Physical Layouts SLUU340A FEBRUARY 2009 REVISED JANUARY 2022 Submi...

Page 8: ...m Layer Routing Physical Layouts www ti com 8 TPS51123 Buck Controller Evaluation Module User s Guide SLUU340A FEBRUARY 2009 REVISED JANUARY 2022 Submit Document Feedback Copyright 2022 Texas Instrume...

Page 9: ...ner Layer 1 www ti com Physical Layouts SLUU340A FEBRUARY 2009 REVISED JANUARY 2022 Submit Document Feedback TPS51123 Buck Controller Evaluation Module User s Guide 9 Copyright 2022 Texas Instruments...

Page 10: ...ner Layer 2 Physical Layouts www ti com 10 TPS51123 Buck Controller Evaluation Module User s Guide SLUU340A FEBRUARY 2009 REVISED JANUARY 2022 Submit Document Feedback Copyright 2022 Texas Instruments...

Page 11: ...il spacing 36 pin strip 0 20 0 30 inch Sullins PTC36DAAN L1 L2 2 Inductor high current 3 3 H 14 A 7 3 m SMT 0 425 0 45 inch Toko FDA1055 3R3M Q1 Q3 2 MOSFET N channel 30 V 11 A 9 1 m SO8 IR IRF7821 Q2...

Page 12: ...erences Texas Instruments TPS51123 Dual Synchronous Step Down Controller with Out of Audio Operation and 100 mA data sheet 9 Revision History NOTE Page numbers for previous revisions may differ from p...

Page 13: ...ther than TI b the nonconformity resulted from User s design specifications or instructions for such EVMs or improper system design or c User has not paid on time Testing and other quality control tec...

Page 14: ...These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not in...

Page 15: ...instructions set forth by Radio Law of Japan which includes but is not limited to the instructions below with respect to EVMs which for the avoidance of doubt are stated strictly for convenience and s...

Page 16: ...any interfaces electronic and or mechanical between the EVM and any human body are designed with suitable isolation and means to safely limit accessible leakage currents to minimize the risk of electr...

Page 17: ...R DAMAGES ARE CLAIMED THE EXISTENCE OF MORE THAN ONE CLAIM SHALL NOT ENLARGE OR EXTEND THIS LIMIT 9 Return Policy Except as otherwise provided TI does not offer any refunds returns or exchanges Furthe...

Page 18: ...change without notice TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource Other reproduction and display of thes...

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