A Low Power Biopotential Amplifier based on Bulk Driven Quasi Floating Gate Technique

Design of low-power and low-noise Biopotential Amplifier (BPA) plays crucial role in the success of high end medical diagnosis systems. However, most of these researched BPAs face a major challenge of consuming large amount of power and also exhibit high values of Noise Efficiency Factor (NEF). Here we report the design of a BPA using Bulk-Driven Quasi-Floating Gate (BDQFG) technique which consumes only low-power $(\mathbf{0.657 \mu \mathrm{W})}$ and also exhibits NEF of 2.06. Circuit design and simulation have been performed in Cadence Analog Design Environment using standard $\mathbf{0.18\ \mu \mathrm{m}}$ technology. Besides promising results on power and noise, design of the BPA using BDQFG technique has also been fine-tuned to achieve mid-band gain of 38.3 dB (from 2.9 Hz to −3dB frequency of 735.5 Hz) and phase margin of 80.6°.