U479B
Automotive Lamp Outage Monitor, VT = 8 mV
Description
The monolithic integrated bipolar circuit, U479B, is designed as a monitor for 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 whereas VT = 8 mV.
If the
voltage drop across shunt resistor, Rsh, 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.
A not used comparator input must be connected to Pin 7.
Features
D D D D
2 kV–ESD protection Two comparators with common reference Tight threshold tolerance Threshold matched to PTC characterist...