L9705

DOUBLE QUAD CONTACT INTERFACE CIRCUIT

ADVANCE DATA

OPERATING DC SUPPLY VOLTAGE RANGE

5V TO 25V

SUPPLY OVERVOLTAGE PULSE UP TO 40V

VERY LOW STAND-BY QUIESCENT CUR-

RENT, MAX 50

µA

INTERNAL CLAMPING DIODES AT CONTACT

INPUTS TO Vs AND gnd WITH PULSE CUR-

RENT CAPABILITY UP TO +50mA, -75mA

CHIP ENABLE FUNCTION AND TRISTATE

OUTPUTS FOR PARALLEL BUS CONNECTION

NOMINAL CONTACT CURRENTS OF 10mA

DEFINED WITH EXTERNAL CONTACT SE-

CONTACT

STATUS

MONITORING

BY

MEANS OF COMPARING THE RESISTANCE

AT CONTACT SENSE INPUTS WITH THE IN-

TERNAL REFERENCE RESISTOR VALUE

RESISTANCE COMPARING WITH HYSTER-

ESIS FOR HIGH NOISE IMMUNITY AND IM-

MUNITY TO GROUND AND BATTERY PO-

TENTIAL DIFFERENCES

DESCRIPTION

The L9705 is a bipolar monolithic integrated cir-

cuit for monitoring the status of up to four con-

tacts connected to GND and up to four contacts

connected to the battery. The contact sense input

supply the contact current and perform the con-

tact resistance comparison function.

At the output the contact status is translated into

a logical LOW level (contact closed) or logical

HIGh level (contact open).

This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

January 1992

BLOCK DIAGRAM

ORDERING NUMBERS : L9705

DIP 20

SO20L

1/8