Input Termination For USB-4431

[kyoung21]

My signal is being driven by a 100 ohm source impedance and is ending at a USB-4431 (USB-4431 Feature Usage - NI).

Should I be terminating at the 4431 with another 100 ohm resistor?

And should I be concerned with the 1k to GND on the pseudo-differential input? That doesn't seem to be able to handle a true differential signal if one side is getting pulled down. 

[Henrik_Volkers · Accepted solution]

the 4431 samples 100kSPS max . For frequencies below 50 kHz you can assume, that the cable is 'just' seen as a capacitance.

The input impedance of the 4431 is 200 kOhm, so check if that load together with your source impedance will hurt you.

[kyoung21]

Thank you. Not sure why I was making that more complicated than it needed to be.

No termination will be necessary.