Cmos operational amplifier

Abstract

Abstract PURPOSE:To improve the degree of freedom of the design by providing symmetrically two sets of differential amplifiers of CMOS constitution and extracting an output from the amplifiers via a push-pull circuit so as to improve the distortion factor characteristic at a low voltage operation. CONSTITUTION:A differential input stage 12 comprising an N-channel MOSFET having a current mirror load 11 and a differential input stage 14 comprising a P-channel MOSFET having a current mirror load 13 are provided symmetrically. Then a signal from the differential input stage 12, 14 is extracted through an output stage 17 of push-pull constitution. When a signal is fed to inverting and non-inverting input terminals 2a, 2b of the circuit, positive/negative half cycles of the input signal are amplified respectively by the differential amplifiers of the input stages 12, 14, applied with push-pull amplification at the output stage 17 and extracted at an output terminal 4. Since the distortion is reduced by the push-pull operation and each differential amplifier has only to handle the half cycle of the input signal, the degree of freedom of the design is improved.

Inventors

• 👤 Miki Abe
• 👤 三樹 阿部
• 👤 Yukiya Tanaka
• 👤 幸也 田中

Bibliographic Details