SC1652 Datasheet, PDF (1/4 Pages) Semtech Corporation – MICROPOWER INVERTING DC-DC CONVERTER

MICROPOWER INVERTING
DC-DC CONVERTER
SC1652
January 29, 1998
TEL:[phone] FAX:[phone] WEB:http://www.semtech.com
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.
BLOCK DIAGRAM
FEATURES
• 2.4V to 7V input voltage operation
• Adjustable output voltage up to -40V
• Low quiescent current at 80µA
• Pulse frequency modulation maintains high
efficiency (max 87%)
• 70kHz to 160kHz switching frequency
• Power-saving shutdown mode (0.7µA typical)
• High efficiency with low cost external PNP bipolar
transistor
APPLICATIONS
• Negative LCD Contrast Bias for
1. Notebook & palmtop computers
2. Pen-based data systems
3. Portable data collection terminals
4. Personal digital assistants
• Negative voltage supplies
ORDERING INFORMATION
DEVICE⁽¹⁾
SC1652CS
V_OUT
Adj
Note:
(1) Add suffix ‘TR’ for tape and reel.
PACKAGE
SO-8
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply Voltage
Operating
Temperature Range
Symbol Maximum
V⁺
7.0
T_A
0 to 70
Units
V
°C
Storage Temperature
Range
T_STG
-65 to 125
°C
© 1997 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320