Hello,
Thanks to your advice, the 360MHz EMI was improved 20dB.
But the result of 180MHz EMI was not good compared with the expectation.
They took a measure as below,
change from 2-layer to 4 layer
Edge guard
stitching capacitor: 30pF
Safety cap: 2200pF
ferrite at Viso and GNDiso
It is helpful if you have advice.
The current noise 54dB
Target noise 40dB
Regards,
Power-man:
Can you share with me images of the 4 layers of the PCB and the component placement and schematic?
Regards, Brian