Infrared pyrolysis control module based on EG4002C

EG4002 is a digital-analog hybrid dedicated chip specially designed for pyroelectric infrared sensor signal amplification and processing output. It integrates an operational amplifier, a dual-threshold voltage comparator, a reference voltage source, a delay time timer and a block time timer. Status controllers, etc., are specially used in anti-theft alarm systems, human body door control devices, lighting control switches, etc. 

   The operating voltage of the EG4002 power supply is +3V ~ +6V. It adopts a COMS process digital-analog mixed integrated circuit and an 8-pin package design, which reduces the number of peripheral circuit components and overall cost, and saves PCB board space.

The hardware circuit is compatible with EG4001 series. It should be directly replaceable.

Problems:

After the diode is welded, the output will pull up the VC voltage, making the chip always in the output state and unable to turn off.

If you are not welding, you can turn off the output after completing a timing cycle, but you cannot trigger it repeatedly.

It is now suspected that the chip function is defective.