L6902D(2002) Datasheet PDF - STMicroelectronics

DESCRIPTION
The L6902D is a complete and simple step down switching regulator with adjustable current limit.
Based on a voltage mode structure it integrates a current error amplifier to have a constant voltage and constant current control.
By means of an on board current sense resistor and the availability of the current sense pins (both compatible to Vcc and for Cs- compatible with GND too) a current limit programming is very simple and accurate (±5%). Moreover constant current control can be used to charge NiMH and NiCd batteries.
The device can be used as a standard DC/DC converter with adjustable current limit (set by using the external sense resistor).

■ UP TO 1A OUTPUT CURRENT
■ OPERATING INPUT VOLTAGE FROM 8V TO 36V
■ PRECISE 3.3V (±2%) REFERENCE VOLTAGE
■ 5% OUTPUT CURRENT ACCURACY
■ OUTPUT VOLTAGE ADJUSTABLE FROM 1.235V TO 34V
■ 250KHz INTERNALLY FIXED FREQUENCY
■ VOLTAGE FEEDFORWARD
■ ZERO LOAD CURRENT OPERATION
■ ADJUSTABLE CURRENT LIMIT
■ PROTECTION AGAINST FEEDBACK DISCONNECTION
■ THERMAL SHUTDOWN

APPLICATIONS
■ CHARGERS FOR NiCd, NiMH BATTERIES AND PREREGULATOR FOR LITHIUM-ION BATTERIES
■ ADJUSTABLE CURRENT GENERATOR
■ SIMPLE STEP-DOWN CONVERTERS WITH ADJUSTABLE CURRENT LIMIT
■ BATTERY EQUIPPED SYSTEMS
■ DISTRIBUTED POWER SUPPLY
■ MOBILE PC & SUBNOTEBOOK