1

FEATURES

APPLICATIONS

DESCRIPTION

TYPICAL APPLICATION CIRCUIT

1

2

3

4

24

23

22

21

DRVH2

VIN

VREG3

EN2

DRVH1

V5SW

RF

EN1

TPS51221RTV

(QFN32)

5

6

7

8

20

19

18

17

PGOOD2

SKIPSEL2

CSP2

CSN2

PGOOD1

SKIPSEL1

CSP1

CSN1

9

32

31

30

29

28

27

26

25

10

11

12

13

14

15

16

VO1

5.0V

L1

C22

VBAT

PowerPAD

C02

C01

VREG5

5V/100mA

R23

R13

C11

R11

PGOOD1

EN

EN1

VREG3

3.3V/10mA

Q11

Q12

Q22

Q21

C13

R12

GND

R14

GND

GND

GND

L2

R24

GND

C23

C21

R21

R22

GND

PGOOD2

EN2

VO2

3.3V

C03

R01

PGND

GND

SKIPSEL1

SKIPSEL2

VBAT

VO2

C12

VBAT

VO1

VO1

VREG5

C14

PGND

PGND

PGND

PGND

PGND

PGND

PGND

C24

GND

R02

C04

IMON1

TPS51221

SLVS786 – NOVEMBER 2007

www.ti.com

Fixed Frequency, 99% Duty Cycle Peak Current Mode

Notebook System Power Controller

• Notebook Computer System and I/O Bus

2

• Input Voltage Range: 4.5 V to 28 V

• Point of load in LCD TV, MFP

• Output Voltage Range: 1 V to 12 V

• Selectable Light Load Operation (Continuous /

Auto Skip / Out-Of-Audio™ Skip)

The TPS51221 is a dual synchronous buck regulator

• Programmable Droop Compensation

controller with 2 LDOs. It is optimized for 5V/3.3V

• Voltage Servo Adjustable Soft Start

system

controller,

enabling

designers

to

cost

• 200 kHz to 1 MHz Fixed Frequency PWM

effectively

complete

2-cells

to

4-cells

notebook

system power supply. The TPS51221 supports high

• Current Mode Architecture

efficiency, fast transient response and 99% duty cycle

• 180° Phase Shift Between Channels

operation. It supports supply input voltages ranging

• Resistor or Inductor DCR Current Sensing

from 4.5V to 28V, and output voltages from 1V to

12V. Peak current mode supports stability operation

• Powergood Output for each channel

with lower ESR capacitor and output accuracy. The

• OCL/OVP/UVP/UVLO protections

high duty (99%) operation and wide input/ output

• Current Monitor Output for CH1

voltage range supports flexible design for small

• Thermal Shutdown (Non-latch)

mobile PCs and a wide variety of other applications.

The fixed frequency can be adjusted from 200 kHz to

• Output Discharge Function (Disable option)

1MHz by a resistor, and each channel runs 180

° out

• Integrated Boot Strap MOSFET Switch

of phase. The TPS51221 can also synchronize to the

• QFN32 (RTV)

external clock, and the interleaving ratio can be

adjusted by its duty. The TPS51221 is available in the

32 pin 5

×5 QFN package and is specified from –40°C

to 85

°C.

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, PowerPAD are trademarks of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Copyright © 2007, 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.