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FEATURES

DESCRIPTION

APPLICATIONS

75 k

Ω

9

10

11

12

PGOOD1

EN1

PGOOD2

EN2

TPS51124RGE

(QFN24)

13

14

15

16

VBST1

DRVL1

LL1

DRVH1

VBST2

DRVH2

LL2

DRVL2

17

8

7

6

5

4

3

2

1

18

19

20

21

22

23

24

VO1

1.05 V/10 A

Q2

IRF8113

L1

Q1

IRF7821

VO2

1.5 V/10 A

Q4

IRF8113

L2

Q3

IRF7821

Input Voltage

3 V to 28 V

PowerPAD

TM

C7

R6

C3

C1

C6

C4

R3

6.8

C8

R7

R1

R2

75

R5

R4

V5IN

4.5 V to 5.5 V

Power

Good2

EN2

C5

C2

Power

Good1

EN1

SGND

PGND

PGND

SGND

C9

SGND PGND

PGND

73.2 k

Ω

k

Ω

28.7 k

Ω

22 µF

2 x 330 µF

1 µH

10 µF

0.1 µF

4.7 F

6.8 k

Ω

1 F

3.3

k

Ω

0.1 µF

10 µF

1 µH

2 x 330 µF

TPS51124

SLVS616A – NOVEMBER 2005 – REVISED NOVEMBER 2005

DUAL SYNCHRONOUS STEP-DOWN CONTROLLER FOR

LOW VOLTAGE POWER RAILS

•

High Efficiency, Low-Power Consumption,

The TPS51124 is a dual, adaptive on-time D-CAP™

Shutdowns to <1

µA

mode synchronous buck controller. The part enables

system designers to cost effectively complete the

•

Fixed Frequency Emulated On-Time Control,

suite of notebook power bus regulators with the

Frequency Selectable From Three Options

absolute lowest external component count and lowest

•

D-CAP™ Mode Enables Fast Transient

standby consumption. The fixed frequency emulated

Response

adaptive on-time control supports seamless operation

•

Auto-Skip Mode

between PWM mode at heavy load condition and

reduced frequency operation at light load for high

•

Less Than 1% Initial Reference Accuracy

efficiency down to milliampere range. The main

•

Low Output Ripple

control loop for the TPS51124 uses the D-CAP mode

•

Wide Input Voltage Range: 3 V to 28 V

that optimized for low ESR output capacitors such as

POSCAP

or

SP-CAP

promises

fast

transient

•

Output Voltage Range: 0.76 V to 5.5 V

response with no external compensation. Simple and

•

separate power good signals for each channel allow

•

Adaptive Gate Drivers With Integrated Boost

flexibility of power sequencing. The part provides a

Diode

convenient and efficient operation with supply input

voltages (V5IN, V5FILT) ranging from 4.5 V to 5.5 V,

•

Internal 1.2-ms Voltage-Servo Soft Start

conversion

voltages

(drain

voltage

for

the

•

Power-Good Signals for Each Channel With

synchronous high-side MOSFET) from 3 V to 28 V

Delay Timer

and output voltages from 0.76 V to 5.5 V.

•

Output Discharge During Disable, Fault

The TPS51124 is available in 24-pin QFN package

specified from –40

°C to 85°C ambient temperature

range.

•

Notebook I/O and Low Voltage System Bus

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.

D-CAP, PowerPAD are trademarks of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Copyright © 2005, 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.