1

FEATURES

APPLICATIONS

DESCRIPTION

7

8

9

10

24

23

22

21

VO1

PGOOD

VBST1

DRVH1

VO2

VREG3

VBST2

DRVH2

TPS51123RGE

(QFN-24)

11

12

20

19

LL1

DRVL1

LL2

DRVL2

13

14

15

16

17

18

6

5

4

3

2

1

PowerPAD

220 nF

20 kW

20 kW

30 kW

100 kW

VREG5

33 mF

5.1 W

0.1 mF

130 kW

130 kW

3.3 mF

330 mF

VO1

5 V

VIN

VREG5

ENC

VIN

10 mF x 2

VIN

5.5 V

to

28 V

EN0

5.1 W

0.1 mF

3.3 mF

330 mF

VO2

3.3 V

10 mF x 2

10 mF

13 kW

UDG-08167

VIN

TPS51123

Dual-Synchronous, Step-Down Controller with Out-of-Audio™ Operation and 100-mA

LDOs for Notebook System Power

• Notebook Computers

2

• Wide-Input Voltage Range: 5.5 V to 28 V

• I/O Supplies

• Output Voltage Range: 2 V to 5.5 V

• System Power Supplies

• Built-in 100-mA 5-V/3.3-V LDO with Switches

• Built-in 1% 2-V Reference Output

• With/Without Out-of-Audio™ Mode Selectable

The TPS51123 is a cost effective, dual-synchronous

Light-Load and PWM only Operation

buck controller targeted for notebook system power

• Internal 1.6-ms Voltage Servo Softstart

supply solutions. It provides 5-V and 3.3-V LDOs and

• Adaptive On-Time Control Architecture with

requires few external components. The TPS51123

Four Selectable Frequency Setting

supports high efficiency, fast transient responses and

provides

a

combined

power-good

signal.

• 4500 ppm/°C R

Out-of-Audio™ mode light-load operation enables low

• Built-In Output Discharge

acoustic

noise

at

much

higher

efficiency

than

• Power Good Output

conventional

forced

PWM

operation.

Adaptive

on-time D-CAP™ control provides convenient and

• Built-in OVP/UVP/OCP

efficient operation. The part operates with supply

• Thermal Shutdown (Non-latch)

input voltages ranging from 5.5 V to 28 V and

• 24-Pin QFN (RGE) Package

supports output voltages from 2 V to 5.5 V. The

TPS51123 is available in a 24-pin QFN package and

is specified from -40°C to 85°C ambient temperature

range.

1

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.

2

Out-of-Audio, D-CAP are trademarks of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Copyright © 2008, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.