SC1628 Datasheet, PDF (1/4 Pages) Semtech Corporation – HIGH-EFFICIENCY STEP-UP DC-DC CONVERTER

HIGH-EFFICIENCY STEP-UP
DC-DC CONVERTER
SC1628
January 30, 1998
TEL:[phone] FAX:[phone] WEB:http://www.semtech.com
DESCRIPTION
The SC1628 is a high performance step-up DC-DC
converter, designed to drive an external power switch
to generate programmable positive voltages. In the
particularly suitable LCD contrast bias and flash
memory programming power supply applications,
typical full load efficiencies are 85% to 95%. The 4V to
24V input operation range allows the SC1628 to be
powered directly by the battery pack in most battery-
powered applications for greater efficiency. The output
voltage can be scaled to 40V or greater 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
100µA and can be reduced down to 8µA in shutdown
mode. With a switching frequency range of 90kHz to
250kHz, small size switching components may be
used, which is ideal for battery powered portable
equipment such as notebook and palmtop computers.
APPLICATIONS
• Flash memory programming power supply
• Positive LCD contrast bias for notebook and palm-
top computers
• Step-up DC-DC converter module
• Telecom power supply
FEATURES
• 4V to 24V input voltage operation
• Adjustable output voltage
• Low quiescent current at 100µA
• Pulse-skipping and pulse-frequency modulation
maintain high efficiency (max. 95%)
• 90kHz to 250kHz oscillator frequency
• Power-saving shutdown mode (8µA typical)
• Push-pull driver output
BLOCK DIAGRAM
ORDERING INFORMATION
DEVICE⁽¹⁾
PACKAGE
SC1628CS
SO-8
Note:
(1) Add suffix ‘TR’ for tape and reel.
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol Maximum Units
Supply Voltage
SHDN Voltage
Operating
Temperature Range
V_IN
V_SHDN
T_A
24
V
15
V
0 to 70
°C
Storage
Temperature Range
T_STG
-65 to 125 °C
© 1997 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320