Do you remember numbers ? I'd guess somewhere in 0.5-1% THD range for simple single opamp servo ? I was kinda mildly interested into doing it for sensors altho

Do you remember numbers ? I'd guess somewhere in 0.5-1% THD range for simple single opamp servo ? I was kinda mildly interested into doing it for sensors altho just microprocessor blasting serial via optocoupler onto other side seems like easier solution... Their application note (page 9) details circuits most audio people would just look at it and go "screw it, i will just buy audio transformer like rest of us" https://www.vishay.com/docs/83708/appnote50.pdf https://www.vishay.com/docs/83708/appnote50.pdf I don't doubt they achieved the claimed values but the circuit to do it had 4 precision opamps (bipolar one have 7) and a bunch of other components so I'm not surprised he didn't want to bother