L9704

March 1992

OCTAL SUPPLY CONTACT MONITORING CIRCUIT

.

OPERATING DC SUPPLY VOLTAGE RANGE

5V TO 25V

.

SUPPLY OVERVOLTAGE PULSE UP TO 40V

.

VERY LOW STANDBY QUIESCENT CUR-

RENT 0.2mA

.

INTERNAL CLAMPING DIODES AT CONTACT

.

INPUT PULSE CURRENT CAPABILITY UP TO

+ 50mA, – 75mA

.

NOMINAL CONTACT CURRENTS OF 10mA

DEFINED BY EXTERNAL CONTACT SERIES

.

CONTACT STATUS MONITORING BY COM-

PARING THE RESISTANCE AT CONTACT

SENSEINPUTS WITH THE INTERNAL REFER-

ENCE RESISTOR VALUE

.

HIGH IMMUNITY DUE TO RESISTANCE COM-

PARISON WITH HYSTERESIS

ORDERING NUMBERS: L9704 (DIP–20)

L9704D (SO–20L)

DIP–20

SO–20L

DESCRIPTION

The L9704 is a bipolar monolithic integrated circuit

for monitoring the status of up to eight contactscon-

nected to the power supply (battery).

It contains eight contact sense inputs and eight mi-

crocomputer compatible three-state outputs.

BLOCK DIAGRAM

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