A vaersatile chopper-stabilized rail-to-rail operational amplifier

This paper presents the design and measured results of a low power high bandwidth versatile rail-to-rail input/output chopper-stabilized amplifier. The core of the amplifier is a folded-cascode OTA, with complementary input pairs for rail-to-rail input capability, a push-pull class-AB output stage is used to provide rail-to-rail output capability. The design also uses complementary current-mirrors and cascode miller compensation, which result in smaller compensation capacitor value and better high-frequency PSRR performance. Choppers at low-impedance nodes are used to further reduce the input referred offset and noise.