PROGRAMMABLE SYNCHRONOUS DC/DC

CONVERTER, DUAL LOW DROPOUT

REGULATOR CONTROLLER

© 1998 SEMTECH CORP.

August 25, 1998

652 MITCHELL ROAD NEWBURY PARK CA 91320

SC1182/3

1

ORDERING INFORMATION

DESCRIPTION

The SC1182/3 combines a synchronous voltage mode

controller with two low-dropout linear regulators

providing most of the circuitry necessary to implement

three DC/DC converters for powering advanced

microprocessors such as Pentium

Deschutes.

The SC1182/3 switching section features an integrat-

ed 5 bit D/A converter, pulse by pulse current limiting,

integrated power good signaling, and logic compatible

shutdown. The SC1182/3 switching section operates

at a fixed frequency of 200kHz, providing an optimum

compromise between size, efficiency and cost in the

intended application areas. The integrated D/A con-

verter provides programmability of output voltage

from 2.0V to 3.5V in 100mV increments and 1.30V to

2.05V in 50mV increments with no external compo-

nents.

The SC1182/3 linear sections are low dropout regula-

tors. The SC1182 supplies 1.5V for GTL bus and 2.5V

for non-GTL I/O.

For the SC1183 both LDO’s are adjustable.

Pentium is a registered trademark of Intel Corporation

TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com

BLOCK DIAGRAM

2.5V/ADJ.

1.5V/ADJ.

1.265V

FET

CONTROLLER

REF.

FET

CONTROLLER

REF.

LDOV

PIN CONFIGURATION

AGND

GATE1

LDOS1

LDOS2

VCC

OVP

PWRGOOD

CS-

CS+

PGNDH

DH

PGNDL

1

2

3

LDOV

4

5

6

7

8

9

10

11

12

24

23

22

21

20

19

18

17

16

15

14

13

VOSENSE

EN

BSTH

BSTL

DL

VID0

VID1

VID2

VID3

VID4

GATE2

Top View

(24 Pin SOIC)

FEATURES

ments

APPLICATIONS

Part Number

(1)

Package

Linear

Voltage

Temp.

Range (T

SC1182CSW

SO-24

1.5V/2.5V 0° to 125°C

SC1183CSW

SO-24

Adj.

0° to 125°C

Note:

(1) Add suffix ‘TR’ for tape and reel.