opamp cancel offset and charge two capacitors to either input voltage or input voltage minus some reference if input exceeded that reference

circuit-20250629-0311.svg

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sim

Can have a double-buffer set of capacitors...in phase one, set one of caps are used for reading and set two is written to, while in phase two, set two of caps are used for reading and set one is written to. Thus can do ADC conversion for any even number of bits.

for the very first bit, can simply read from the audio input. Subsequent bits will alternate between reading and writing with the two alternating sets of capacitors.

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