• Resolved

TRS3122E: Serial Resistors Selection/Calculation for Rin

Part Number: TRS3122E

I have used a pair of the TRS3122E as the evaluation board and choose R6 and R7 with 50 Ohm.  During the common noise test - injecting 1000V, 100kHz signal into the GND of the TR3122E and the chassis ground, the communication is disrupted.  After change R6 and R7 back to 0 Ohm, the common mode noise immunity is much better.  Do you have any application note or suggestion on how to select the proper R6 and R7?  Or this is bus specific?  Is it possible to give an example on how to select the correct value for R6 and R7?  We could not even measure the waveform properly when common mode noise is being injected.

Thank you very much,

Frank W.