DRV8880EVM GND plane resonance simulation

Hi Wilson,

I'm sorry. I ask a question again.

My customer is using DRV8880EVM.
He has a question about GND plane resonance simulation of EVM.
Could you let me know whether or not GND plane resonance simulation did at EVM, please?

This question's background is a noise(sound) from motor when motor stop.
Seting is the following at EVM.
- TOFF : 10us
- Deacy : Adaptive decay
- Step : 1/4
- VM : 33V
- chopping current : 0.5A
- torqu: 100%

I heard noise at 72~75kHz PWM frequency.
We don't understand this mechanism of this issue.
I posted because I think this issue's cause may be noise by GND plane resonance.

Thanks
Shimizu

Hi Wilson,

Thank you four your support.

Yes. 
The reason of this question is noise from motor when motor stop .
After a customer made GND large at customer's previous product which does not use DRV8880, noise became to be off.
For the reason, customer asked me this question.　

Thanks
Shimizu