Patent ID: 7034615

Claim:
A CMOS operational amplifier comprising: an amplifying unit for differentially amplifying signals inputted to an inverting input terminal and non-inverting input terminal to reduce an input offset voltage and outputting the amplified signal to an output terminal; and a slew enhancing unit for increasing a slew rate of the amplified signal outputted to the output terminal of the amplifying unit on the basis of the input voltage value of the inverting input terminal and the input voltage value of the non-inverting input terminal, wherein the amplifying unit comprises: a first differential amplifier including the inverting input terminal and the non-inverting input terminal of the amplifying unit and for differentially amplifying a signal inputted to the inverting input terminal and the non-inverting input terminal; a symmetrical amplifier for generating a signal symmetrical to the signal outputted from a non-inverting output terminal of the first differential amplifier and differentially amplifying the generated signal and the signal outputted from the non-inverting output terminal of the first differential amplifier; and an amplified signal output unit for differentially amplifying signals inputted from an inverting output terminal and a non-inverting output terminal of the symmetrical amplifier and outputting the amplified signals to the output terminal of the amplifying unit.