Apparatus and methods for chopper amplifiers

摘要

Apparatus and methods for chopper amplifiers are provided herein. In certain configurations, a chopper amplifier includes at least one differential transistor bank including a selection circuit and a plurality of transistors. The selection circuit can select a first portion of the transistors for operation in a first transistor group and a second portion of the transistors for operation in a second transistor group. During calibration, the chopper amplifier's input offset can be observed for different transistor configurations of the differential transistor banks. Although the transistors of a particular bank can be designed to have about the same drive-strength and/or geometry, the chopper amplifier can have a different input offset in different transistor configurations due to manufacturing mismatch between transistors, such as process variation. The chopper amplifier can be programmed to operate with the selected transistor configurations of the differential transistor banks to provide the amplifier with low input offset.

主权项

1. An apparatus comprising:
a programmable memory configured to generate a first control signal; and a chopper amplifier configured to amplify a differential input voltage signal to generate an output signal, wherein the chopper amplifier comprises:
a first differential transistor bank comprising a selection circuit and a plurality of transistors, wherein the selection circuit is configured to select a first portion of the plurality of transistors for operation in a first transistor group based on the first control signal, and wherein the selection circuit is further configured to select a second portion of the plurality of transistors for operation in a second transistor group based on the first control signal,wherein an input offset voltage of the chopper amplifier varies based on a selection of transistors in the first and second transistor groups.