the circuit will be DC, as far as this amp is concerned. i will probably build it on a 20v process, but that does not matter as far as the circuit is concerned - i could build it on 80v process and just change mosfet models...
Setting the range of the current will change depending on user selection, but i have already designed that part.
Basically, I am sensing current limit across an NMOS. I can use sense transitors if I want to get current output instead of voltage output, but layout is a little trickier..
The smallest IC will have about 100mA ILIM, biggest part will be up to 3-5A.. This is no big deal, we are just sensing a few mV in either case. Accuracy should be about 0.1% of the range. (like 1mA on 1A Ilimit, 100uA on 100mA Ilimit).
What approach do you think?