© 1997 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA 91320

MICROPOWER INVERTING

DC-DC CONVERTER

SC1652

January 29, 1998

Note:

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

PIN CONFIGURATION

FEATURES

efficiency (max 87%)

transistor

DESCRIPTION

The SC1652 is a high performance inverting DC-DC

converter, designed to drive an external power switch

to generate programmable negative voltages. In the

particularly suitable LCD bias contrast application,

efficiency of 87% can be achieved with low cost PNP

bipolar transistor drivers. The output voltage can be

scaled to -40V by two external resistors. A pulse

frequency modulation scheme is employed to maintain

high efficiency conversion under wide input voltage

ranges. Quiescent current is about 80µA and can be

reduced to 0.7µA in shutdown mode. With a switching

frequency range of 70kHz to 160kHz, small size

switching components may be used, which is ideal for

battery powered portable equipment such as notebook

and palmtop computers.

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

APPLICATIONS

1.

Notebook & palmtop computers

2.

Pen-based data systems

3.

Portable data collection terminals

4.

Personal digital assistants

DEVICE

(1)

V

OUT

PACKAGE

SC1652CS

Adj

SO-8

ORDERING INFORMATION

ABSOLUTE MAXIMUM RATINGS

Parameter

Symbol

Maximum

Units

Supply Voltage

V

+

7.0

V

Operating

Temperature Range

T

A

0 to 70

°C

Storage Temperature

Range

T

STG

-65 to 125

°C

BLOCK DIAGRAM