L497

March 1998

HALL EFFECT PICKUP IGNITION CONTROLLER

.

DIRECT

DRIVING

OF

THE

EXTERNAL

POWER DARLINGTON

.

COIL CURRENT CHARGING ANGLE (dwell)

CONTROL

.

PROGRAMME COIL CURRENT PEAK LIMITA-

TION

.

PROGRAMMABLE DWELL RECOVERY TIME

WHEN 94 % NOMINAL CURRENT NOT

REACHED

.

RPM OUTPUT

.

PERMANENT CONDUCTION PROTECTION

.

OVERVOLTAGE PROTECTION FOR EXTER-

NAL DARLINGTON

.

INTERNAL SUPPLY ZENER

.

REVERSE BATTERY PROTECTION

DESCRIPTION

The L497 is an integratedelectronic ignition control-

ler for breakerless ignition systems using Hall effect

sensors.

ORDERING NUMBERS : L497B (DIP16)

L497D1 (SO16)

DIP16

SO16

The device drives an NPN external darlington to

control the coil current providingthe required stored

energy with low dissipation.

A special feature of the L497 is the programmable

when the coil peak current fails to reach 94 % of the

nominal value. In this way only one spark may have

an energy less than 94 % of the nominal one during

fast acceleration or cold starts.

BLOCK DIAGRAM

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