ESD issue in enCoRe II devices

Question: When we use the Zener on D+ and D- and between the GND and PWR planes we get corruption on the D+/D- lines in the enCoRe II device. The device is subjected to 4kV of ESD. How to limit this effect?

 

Answer:

The connection between the signal ground and ground shield may give rise to a problem if they are shorted directly because the part CY7C63723 will only see the 4KV and will result in failed ESD. You may use a RC or LC combination normally to avoid this problem.