I am trying to read PARD (periodic and random deviation also call ripple an noise) in the range of 300-700mVp-p of a power supply with a 48Vdc output. I am wanting to display the result to a digital display. I am looking at using a op-amp super diode with the power supply output capacitively coupled. Is their a circuit already existing to accomplish this?

 

I have moved this question to a more appropriate forum, where you are likely to get better responses. Speaking for myself, I use an oscilloscope.

 

What is the maximum frequency of the PARD you must measure?