POWER MANAGEMENT

1

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SC2602/SC2602A

Synchronous Voltage Mode Controller

for Distributed Power Supply Applications

Features

Applications

Revision: November 18, 2004

Typical Application Circuit

Description

Synchronous operation for high efficiency (95%)

R

On-chip power good and OVP functions

Small size with minimum external components

Soft Start

Enable function

Microprocessor core supply

Low cost synchronous applications

Voltage Regulator Modules (VRM)

DDR termination supplies

Networking power supplies

Sequenced power supplies

The SC2602 and SC2602A are low-cost, full featured,

synchronous voltage-mode controllers designed for use

in single ended power supply applications where efficiency

is of primary concern. Synchronous operation allows for

the elimination of heat sinks in many applications. The

SC2602s are ideal for implementing DC/DC converters

needed to power advanced microprocessors in low cost

systems, or in distributed power applications where effi-

ciency is important. Internal level-shift, high-side drive

circuitry, and preset shoot-thru control, allows the use of

inexpensive N-channel power switches.

SC2602s features include temperature compensated

voltage reference, triangle wave oscillator and current

sense comparator circuitry. Power good signaling, shut-

down, and over voltage protection are also provided.

The SC2602 operates at a fixed 200kHz and the

SC2602A at 500kHz, providing a choice for optimum

compromise between efficiency, external component size,

and cost.

Two SC2602s can be used together to sequence power up

of telecom systems. The power good of the first SC2602

connected to the enable of the second SC2602 makes

this possible.

Typical Distributed Power Supply

Figure 1.

VCC

1

PWRGD

2

OVP

3

OCSET

4

PHASE

5

DRVH

6

PGND

7

DRVL

8

BSTL

9

BSTH

10

SENSE

11

SS/SHDN

13

GND

14

U1

SC2602

Q1

STP40NE

Q2

STP40NE

R5

3.9

L1

2uH

C9

180/4V

C10

180/4V

C11

180/4V

C12

180/4V

C7

680/6.3V

C6

680/6.3V

R1

1k

R3

1k

C2

0.1

C3

0.1

C1

0.1

R2

PWRGD

OVP

SHDN

+

_

+

_

Vin

5V

Vout=2.5V

*

R7

127

R8

124*

NOTE:

*) Vout = 1.265 x (1+R8/R7)

+5V

D1

MBR0520

R6

2.2

C4

1.0

C5

10.0

C8

680/6.3V

R4

10

+12V

C13

180/4V

0.1

COMP

12

4.99K

820pF