Post Go back to editing

AD8313 detector output with periodic pulse output

A phenomenon was discovered when testing with AD8313 chip recently. When there is interference from mobile phone signals, the chip will output a periodic pulse signal, which will last for a few minutes and then disappear instantly. If the mobile phone is used again for interference, this pulse phenomenon will appear again. This phenomenon can occur when the chip is powered by a battery or a linear power supply. I don't know where to improve the test.

  • Hello Runoob,

    The mobile phone signal at RF will sometimes find its way into the detector input through free space propagation. The RF input trace consisting of P2 and C3 can function as a low gain antenna and hence pickup the mobile phone signals, then the AD8313 detects the signal. The cure is better shielding of the input trace and detector circuitry.   -Bruce H. 

  • Hello Bruce_H

    Thank you for your detailed answer. I will add a stainless steel shielding cover to the PCB board later. After testing, the pulse signal is indeed the mobile phone signal. If it is far away from my workbench, there is no such problem.