I am building a chopper amplifier to remove 1/f noise. I used ADG1436YRUZ as the modulator for the differential input; then modulated the differential signal is amplified and converted to single ended signal; then this signal and its inverted signal is passed through ADG1419BRMZ for demodulation. For current board, it still has 1/f noise, (around 1Hz). I will improve the clock distribution in next version. But I don't see any schematic mentioning using ADG analog mux as chopper switch. All of the article talking about using discrete NMOS for chopper switches. Is there problem for me to use ADG for this purpose?
Hi, David:
Thanks for the reply!
After I did more study, I understand now that I can not use ADG1436 and ADG1419 due to their large charge injection, instead I can use ADG733. The reason I am not using zero drift amplifier is that the noise level I need to below 0.8nV/sqrt(Hz) for frequency > 0.1Hz. The best auto zero amplifier will be around 15nV.
Hi, David:
Thanks for the reply!
After I did more study, I understand now that I can not use ADG1436 and ADG1419 due to their large charge injection, instead I can use ADG733. The reason I am not using zero drift amplifier is that the noise level I need to below 0.8nV/sqrt(Hz) for frequency > 0.1Hz. The best auto zero amplifier will be around 15nV.