Accurate low-power CMOS autozeroed comparator

A low-power CMOS autozeroed comparator suitable for high-frequency A/D convertors is discussed. The use of a source follower in the autozeroed inverter stage allows the circuit to provide an optimum tradeoff between speed, gain and power dissipation. Relationships are given that relate the time response, both in the autozeroing and comparating phase, to the circuit parameters. An experimental prototype, fabricated with a 2 mu m CMOS process is also presented.