1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

SOFTSTART

INV

FB

GND

REF

COMP

PWMSKIP

STBY

LH

OUT_u

LL

OUT_d

OUTGND

TRIP

VCC_SENSE

VCC

VREF5

VREG5V_IN

DB PACKAGE

(TOP VIEW)

TPS5103

MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER

SLVS240 – SEPTEMBER 1999

1

POST OFFICE BOX 655303

– Heavy Load:

– Fixed Frequency PWM

– Hysteretic (User Selctable)

– Light Load:

– Skip Mode

description

The TPS5103 is a synchronous buck dc/dc controller, designed for notebook PC system power. The controller

has three user-selectable operation modes available; hysteretic mode, fixed frequency PWM control, or SKIP

control.

In high current applications, where fast transient response is advantageous for reducing bulk capacitance, the

hysteretic mode is selected by connecting the Rt pin to Vref5. Selecting the PWM/SKIP modes for less

demanding transient applications is ideal for conserving notebook battery life under light load conditions. The

device includes high-side and low-side MOSFET drivers capable of driving low Rds (on) N–channel MOSFETs.

The user-selectable overcurrent protection (OCP) threshold is set by an external TRIP pin resister in order to

protect the system. The TPS5103 is configured so that a current sense resistor is not required, improving the

operating efficiency.

R1

R2

1

SOFTSTART

2

INV

3

FB

4

CT

5

RT

6

GND

7

REF

8

COMP

9

PWM/SKIP

10

STBY

19

OUTU

17

OUTD

16

OUTGND

15

TRIP

14

VCCSENSE

12

VREF5

11

VREG5V_IN

13

VCC

20

LH

18

LL

TPS5103

U1

C2

C1

R3

R4

D1

C3

L1

OUTPUT

+

5 V

C4

C5

Q2

Q1

Figure 1. Typical Design

Copyright

© 1999, Texas Instruments Incorporated

PRODUCT PREVIEW information concerns products in the formative or

design phase of development. Characteristic data and other

specifications are design goals. Texas Instruments reserves the right to

change or discontinue these products without notice.

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.

TI is a trademark of Texas Instruments Incorporated.