A CMOS instrumentation amplifier with low voltage and low noise for portable ECG monitoring systems

Abstract

A low voltage, low noise instrumentation amplifier (IA) applicable for Electrocardiogram signal acquisition system has been designed. The circuit is based on the current feedback topology which has been implemented using folded cascode structure at the input stage. It works at zero input common mode voltage with 1V supply. It has a wide input dynamic range of plusmn0.01 mV to plusmn1.2 mV. The voltage gain is 45 dB and it consumes 165 muW power. A high common mode rejection ratio (CMRR) of 125 dB has been achieved. The integrated input referred noise is 3 muV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> (0.2Hz - 150 Hz). The design has been done in 0.18 mum standard CMOS process.