SDRookie
Junior Member level 2
Hi,
I'm designing a fully differential amplifier. My block include a amplifier 30dB gain open loop and a common mode feedback circuit with 20dB gain.
when the input have dc offset (0.1V), it saturate the output, so one output port of differential amplifier's voltage reach VDD, which is turned off.
I think the common mode feedback should correct the dc output voltage, but it didn't work. Could someone tell me how should I prevent this happen? should i increase gain of common mode fb block?
I'm designing a fully differential amplifier. My block include a amplifier 30dB gain open loop and a common mode feedback circuit with 20dB gain.
when the input have dc offset (0.1V), it saturate the output, so one output port of differential amplifier's voltage reach VDD, which is turned off.
I think the common mode feedback should correct the dc output voltage, but it didn't work. Could someone tell me how should I prevent this happen? should i increase gain of common mode fb block?