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)

Features

■ Up to 1 A output current

■ Operating input voltage from 8 V to 36 V

■ Precise 3.3 V (±2) reference voltage

■ 5 output current accuracy

■ Output voltage adjustable from 1.235 V to 34 V

■ 250 kHz 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 and subnotebook