mangk
Junior Member level 1
Hi, I have a question regarding differential negative feedback circuit, addressed in Design of analog CMOS integrated circuits written by Razavi.
On page 314 (Figure 9.30 (b)), Each output of an fully differential amplifier is shorted to the input of the amplifier to address the need for CMFB(Common mode feedback).
(Resistor load is used in the circuit)
And the author said that the input and output common-mode level in this case are quite well-defined... which is understandable.
My question is, "when do we use this kind of circuit?"
In my thinking, it only loads source signal by adding a parallel impedance to output load.
Thank you.
On page 314 (Figure 9.30 (b)), Each output of an fully differential amplifier is shorted to the input of the amplifier to address the need for CMFB(Common mode feedback).
(Resistor load is used in the circuit)
And the author said that the input and output common-mode level in this case are quite well-defined... which is understandable.
My question is, "when do we use this kind of circuit?"
In my thinking, it only loads source signal by adding a parallel impedance to output load.
Thank you.
