November 2010

Doc ID 7332 Rev 9

1/11

11

L6902

Up to 1 A switching regulator with adjustable current limit

Features

Applications

preregulator for lithium-ion batteries

current limit

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).

The internal robust P-channel DMOS transistor

with a typical of 250 m

Ω assures high efficiency

and a minimum dropout even at high output

current level. The internal limiting current (latched

function) of typical value of 2.5 A protects the

device from accidental output short circuit

avoiding dangerous loads damage.

If the temperature of the chip goes higher than a

fixed internal threshold (150°C with 20°C

hysteresis), the power stage is turned off.

Other protections beside thermal shutdown

complete the device for a safe and reliable

application: overvoltage protection, frequency

folback overcurrent protection and protection vs.

feedback disconnection.

The internal fixed switching frequency of 250KHz,

and the SO-8 package pin allow to built an ultra

compact DC/ DC converter with a minimum board

space.

Table 1.

Device summary

Order codes

Package

Packaging

L6902D

SO-8

Tube

L6902D013TR

Tape and reel

SO-8

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