Input Protection for Low-Distortion Op-Amp Circuits

[waltr]

Here is a link to a paper on Electronic Design's web site.
Some interesting ideas for op-amp input protection that would be applicable to PI detectors.

Most interesting is the use of Depletion Mode MOSFETs.

https://www.electronicdesign.com/tec...opamp-circuits

[ZED]

An enlightening article,parasitic capacitance on the input circuits to preamps can be problematic,its one of the reasons why i use discrete preamps,plus i avoid input protection diodes.

[ivconic]

Problem rises with frequency... or PPS , put it as you like..
Obviously just bellow 1kHz is the "safe zone" to use even ordinary 1N4148 to clamp the signal.
However; this all makes more sense with PPS over 1kHz.
There are some PI's working up to 3kHz so these considerations are pretty beneficial.
Good article.