AnsweredAssumed Answered

ADM2687 Emission Problem

Question asked by on Jun 29, 2015
Latest reply on Jun 30, 2015 by RAnslow

Hello ,


My name is Meir and I am DFAE.


One of my customers use the ADM2687 - Signal and Power Isolated RS-485 Transceiver.

They have an emission issue on ~180MHz frequency and 360MHz frequency (the second harmony) and they can't to pass the EMC/EMI sertification.

We suppose that this emission is a result of the oscillator of integrated Isolated power supply that his frequency is 180MHz.

Please see the attached files:

Schematics, PCB Layout, Radiated emissions results.

With the special probe we saw that the emission come from the chip.

Appreciate if you could help us to solve this problem.

Thanks a lot,