Th integrated bipolar circuit is designed to monitor lamp failure in automobiles. The comparator threshold is matched to the PTC characteristic of incandescent lamps. The threshold is tied to V4,6 = VS - VT where VT = 8 mV. If the voltage drop across the shunt resistor exceeds 8 mV, the output is turned off, otherwise, the output is turned on. Without supply voltage or open input pin 8, the output is turned off.