Analysis of Programmable Gain Instrumentation Amplifier

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Abstract

This paper presents an analysis of the design of a programmable gain amplifier (PGA) based on an instrumentation amplifier. The instrumentation amplifier can be implemented in different ways, including the Single Op amp IA, 2 Op-amp INA, 3 Op-amp INA, Switched Capacitor Instrumentation amplifier (SCIA), Current Feedback Instrumentation amplifier (CFIA), Current Mirror Instrumentation amplifier (CMIA), and others. By adding switches or a multiplexer (Mux) to the amplifier, a precision programmable gain instrumentation amplifier (PG-IA) can be created. The literature suggests various approaches for enhancing the performance parameters of a PGINA, and this study aims to bring together and evaluate these approaches on a unified platform. In this research, an extensive examination of multiple instrumentational amplifier topologies has been carried out, and these topologies have been categorized based on their distinctive characteristics.

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Keywords

Programmable gain amplifier (PGA); Instrumentation Amplifier (INA); Common Mode Rejection Ratio (CMRR); Complementary Metal Oxide Semiconductor (CMOS); Phase Margin (PM)