CMOS low-power consumption, low offset voltage, low return-stroke noise comparator

The invention discloses a CMOS comparator with low power consumption, low offset voltage and low return noise, belonging to the technical field of the radio communication system. The CMOS comparator comprises a preposing amplifier, a pair of switch tubes, a positive feedback latch unit, a CMOS phase inverter and an SR latch unit, wherein the preposing amplifier adopts a PMOS tube to serve as the input differential pairs, a diode is connected with an NMOS tube and is connected with a circuit structure which is in positive feedback connection with the NMOS tube in parallel to serve as the load so as to reduce the offset voltage of the comparator; the pair of the switch tubes is inserted between the preposing amplifier and the positive feedback latch unit so as to reduce the return noise of the comparator; and the positive feedback latch unit adopts a cross-coupling CMOS inverter circuit structure, a reset pipe is connected between regenerating nodes, thereby not only reducing the power consumption but also increasing the regenerating speed. The comparator has good properties of low power consumption, low offset voltage and low return noise, does not need to adopt the offset cancelingtechnique, and can be widely applied to a low power consumption high-speed AD converter with 6 to 8 medium and high accuracy of a radio communication system.