View l9704 datasheet:

L9704 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 INPUTS TO V AND GND S .INPUT PULSE CURRENT CAPABILITY UP TO DIP–20 + 50mA, – 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 THEINTERNAL REFER- ENCE RESISTOR VALUE .HIGH IMMUNITY DUE TO RESISTANCE COM- SO–20L PARISON WITH HYSTERESIS ORDERING NUMBERS: L9704 (DIP–20) L9704D (SO–20L) DESCRIPTION The L9704 is a bipolar monolithic integrated circuit It contains eight contact sense inputs and eight mi- for monitoring the statusof up to