L9704
OCTAL SUPPLY CONTACT MONITORING CIRCUIT
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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
INPUTS TO V
S
AND GND
INPUT PULSE CURRENT CAPABILITY UP TO
+ 50mA, 鈥?75mA
NOMINAL CONTACT CURRENTS OF 10mA
DEFINED BY EXTERNAL CONTACT SERIES
RESISTORS R
IN1-8
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
DIP鈥?0
SO鈥?0L
ORDERING NUMBERS:
L9704 (DIP鈥?0)
L9704D (SO鈥?0L)
DESCRIPTION
The L9704 is a bipolar monolithic integrated circuit
for monitoring the status of up to eight contactscon-
nected to the power supply (battery).
BLOCK DIAGRAM
It contains eight contact sense inputs and eight mi-
crocomputer compatible three-state outputs.
March 1992
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