I'm looking to design a small (physically) and preferably simple AGC to precondition a line audio input before it gets to a uP ADC or ZCD input. Lo-Fi is acceptable - what I'm really looking for if a reasonable input dynamic range and an output that is uP-friendly, A pair of diodes is not enough!
I have thought of fully-integrated devices such as the SSM2166, but these are expensive and I really don't need that level of sophistication as I'm only looking at 8-bit ADC or even just zero-crossing sensing.
Traditional solutions have tended to involve transconductance amps and a peak level detector, but I was wondering if there was any really simple way of doing this...
[while an AVR maybe the ultimate goal for the signal this isn't really about using AVRs per se so I'm going to move this to General Electronics - Cliff]