I have a design checklist question for a typical CAN circuit for an automotive application as below : The question is related to the ESD suppressor : "Was a capacitor parallel to the diode considered, respectively carefully proofed the max. power losses in case of high-frequency distortion ? (Critical : overloading of diode through current loading during BCI-test)" My application circuit is something similar to the below circuit, except that there are capacitors on the CAN lines on the other side of the ESD diode(NUP2105L) near the CAN bus, as well.
I understand that the diode is for clamping high voltage surges and the capacitors are to smooth out the noise on the CAN lines, and BCI effect on the CAN lines is high frequency noise- I'm imagining this is what the CAN lines see during BCI test(I have actually asked a question regarding this, but unfortunately couldn't get an answer, Bulk Current Injection on CAN bus )
So, thinking of an answer to the question above, a capacitor parallel to the diode is considered(but is my thinking right ? are they asking about the capacitor on the other side of the diode- nearer to the CAN bus), but I don't know how to proof the maximum power losses in case of high frequency. Also how do I quantitatively calculate the overloading of the ESD diode during BCI.