A New Transresistance-Mode Instrumentation Amplifier with Low Number of MOS Transistors and Electronic Tuning Opportunity

Abstract

In this paper, the simplest possible electronically adjustable transresistance-mode (TRM) instrumentation amplifier (IA) using only eight MOS transistors is presented. Extremely simple structure of the proposed IA leads to a wide bandwidth and robust performance against mismatches and parasitic capacitances. Of more interest is that the differential-mode gain of the proposed IA can be electronically varied by control voltages. Post-layout and pre-layout simulation results based on 0.18[Formula: see text][Formula: see text]m TSMC CMOS parameters are included to confirm the validity of the theoretical analysis. Despite extremely simple structure, its input and output impedances are 1.93 and 1.68[Formula: see text]k[Formula: see text], respectively. Time domain analysis shows that for an input signal of 20[Formula: see text][Formula: see text]A peak to peak, maximum value of THD is 4.5% for different frequencies. Monte Carlo simulation is also carried out, which proves robust performance of the proposed IA against mismatches. The required chip area is only [Formula: see text].