Input common-mode feedback technique for very low voltage CMOS amplifiers

A technique for low supply voltage CMOS amplifiers is presented. The technique shifts and attenuates the common-mode (CM) component of the signals existing at two input terminals, by means of a negative feedback loop which only acts over this CM component. It is very useful for extending the signal swing up to the rails for amplifiers operating in the total supply voltage range of 1 V and below. Some continuous-time (CT) and discrete-time (DT) applications of the technique are discussed.