simplsoft
Full Member level 2
Hello
Can any one tell me about the common mode feedback circuit (CMFB) which is required in a differential amplifier. Does this CMFB circuit only detects the DC voltage because the input of differential pair is Vin=Vcm+Vd. where Vcm is the common mode dc voltage and Vd is the diffferetial ac signal voltage. So if this CMFB is for detecting the common mode output of differential pair it means its going to detect the DC voltage at the output only?
Please can anyone tell me why for only dc voltage CMFB is used not for ac?
Thanx
Can any one tell me about the common mode feedback circuit (CMFB) which is required in a differential amplifier. Does this CMFB circuit only detects the DC voltage because the input of differential pair is Vin=Vcm+Vd. where Vcm is the common mode dc voltage and Vd is the diffferetial ac signal voltage. So if this CMFB is for detecting the common mode output of differential pair it means its going to detect the DC voltage at the output only?
Please can anyone tell me why for only dc voltage CMFB is used not for ac?
Thanx