Why does ADUM4160 fail,just a finger touch on the component's top of the surface.

This is the signal coming out from MCP_DN. Looks like the signal is not smooth.

Even the MCP_DP is not smooth signal. What do you think about these signals?

 

What exactly do you mean by 'fail'? I've not used that device before but in general. The two USB data signals, P(os) and N(eg), form a balanced pair.


The physical bus signals might look noisy on the cable wires depending on the scope common/gnd reference and signal speed.

https://www.analog.com/en/resources...s/switching-in-usb-consumer-applications.html