Switched-capacitor pulse-width programmable gain integrating amplifier

Abstract

With the purpose of realizing an integrated circuit and knowing that the capacitors generally use less space than resistors in the integration process, we propose an architecture of a pulse-width programmable linear amplifier that uses a switched capacitor instead of resistors. This architecture was obtained from modifications of a programmable gain amplifier developed in previous work. The proposed circuit is composed of switches, capacitors and an operational amplifier, and use three groups of signals for activating the switches, which among other functions, allows the amplifier's gain selection. The circuit also allow the selection of operating modes that can be a single-ended mode, a differential mode, and calibration mode. Simulation and experimental results with a prototype created from the proposed architecture are presented and compared with the previous work.