Optimization of Power and Area in Low-Noise CMOS Bio-Signal Amplifiers

Area and power consumption are the most important parameters in integrated bio-potential signal amplifier with low noise and low bandwidth requirements. In this paper we present an analytical method for optimizing differential amplifiers for a constant input-referred noise level. Power- area optimization is performed over 1mHz to 10kHz in a 0.18μm CMOS technology. The amplifier consumes 22μA from a 1.8V power supply and the total equivalent input-referred noise over that bandwidth is equal to 2.4μVrms. The results, validated by SPICE circuit simulations, indicate that the amplifier can be optimized for specific input-referred RMS noise level.

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