A Resistorless Temperature-insensitive Electronically-adjustable Single VDGA-based Voltage-mode Instrumentation Amplifier

This article describes a novel voltage-mode instrumentation amplifier with fully electronic controllability and temperature insensitivity. Its circuit description is very simple comprising only single active building block namely voltage differencing gain amplifier (VDGA) without any passive elements to achieve high differential-mode gain and common-mode rejection ratio (CMRR). Its gain can be widely adjustable by electronic method via input bias currents, it then can be easily modified to automatic or microcontroller-based control systems. Several performances of workability of the proposed instrumentation amplifier are disclosed using PSpice simulation with the model parameter of 0.25μm CMOS process. The output deviation due to temperature variation is about 0.00135%/°C. The total harmonic distortion (THD) of output voltage is 0.89%. Total power consumption of the proposed circuit is 0.18mW at ±1.2V power supply.