How to calculate the trace resistance with 20KHz PWM current

[ykykouai]

Hi, Here is the question.
I want to calculate a trace resistance with a 20khz PWM current. I use the DC resistance way to do it. Like R=ρ*L/A. Is it okay? Or there is any suggestion?

 

[FvM]

The short version: Skin depth for copper conductors at 20 kHz is about 0.5 mm, so you can calculate with DC resistance in first estimation.

The long version: The conductor geometry must be considered, proximity effect can become relevant in some cases.