SC1186(1999) View Datasheet(PDF) - Semtech Corporation

Part Name

Description

Manufacturer

SC1186
(Rev.:1999)

PROGRAMMABLE SYNCHRONOUS DC/DC CONVERTER, DUAL LOW DROPOUT REGULATOR CONTROLLER

Semtech Corporation 

PRELIMINARY - December 2, 1999

PROGRAMMABLE SYNCHRONOUS DC/DC

CONVERTER, DUAL LOW DROPOUT

REGULATOR CONTROLLER

SC1186

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

DESCRIPTION

The SC1186 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® II & III.

The SC1186 switching section features an integrated

5 bit D/A converter, latched drive output for

enhanced noise immunity, pulse by pulse current

limiting and logic compatible shutdown. The SC1186

switching section operates at a fixed frequency of

140kHz, providing an optimum compromise between

size, efficiency and cost in the intended application

areas. The integrated D/A converter 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 components.

The SC1186 linear sections are low dropout regula-

tors with short circuit protection, supplying 1.5V for

GTL bus and 2.5V for non-GTL I/O. The Reference

voltage is made available for external linear

regulators.

FEATURES

• Synchronous design, enables no heatsink solution

• 95% efficiency (switching section)

• 5 bit DAC for output programmability

• Designed for Intel Pentium® ll & III requirements

• 1.5V, 2.5V short circuit protected linear controllers

• 1.265V ± 1.5% Reference available

APPLICATIONS

• Pentium® ll & III microprocessor supplies

• Flexible motherboards

• 1.3V to 3.5V microprocessor supplies

• Programmable triple power supplies

ORDERING INFORMATION

Part Number(1)

Package

Linear

Voltage

Temp.

Range (TJ)

SC1186CSW SO-24 1.5V/2.5V 0° to 125°C

Note:

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

PIN CONFIGURATION

BLOCK DIAGRAM

Top View

AGND

1

GATE1

2

LDOS1

3

LDOS2

4

VCC

5

REF

6

LDOEN

7

CS-

8

CS+

9

PGNDH 10

DH 11

PGNDL 12

24

GATE2

23

LDOV

22

VID0

21

VID1

20

VID2

19

VID3

18

VID4

17

VOSENSE

16

EN

15

BSTH

14

BSTL

13

DL

(24 Pin SOIC)

VID4

VID3

VID2

VID1

VID0

VOSENSE

AGND

LDOEN

LDOS1

GATE1

VCC

CS- CS+

EN

REF

70mV

CURRENT

LIMIT

+

-

+

D/A

-

-

ERROR

+

AMP

OSCILLATOR

R

Q

S

2.5V FET

CONTROLLER

1.265V

REF

1.5V FET

CONTROLLER

LDOV REF

GATE2 LDOS2

LEVEL SHIFT AND

HIGH SIDE DRIVE

BSTH

DH

PGNDH

SHOOT-THRU

CONTROL

SYNCHRONOUS

MOSFET DRIVE

BSTL

DL

PGNDL

© 1999 SEMTECH CORP.

Pentium is a registered trademark of Intel Corporation

1

652 MITCHELL ROAD NEWBURY PARK CA 91320

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