Low-Noise Biopotential Recording Circuit with Correlated Timeshare Sampling

Low-noise biopotential readout circuit for CMOS front-end micro system is presented using correlated double sampling (CDS) technology. CDS technology provides an excellent method for the reduction of KTC noise and 1/f noise in low-frequency signal processing, and because of its simple circuit structure it can be a widespread application for neural signal recording. The proposed readout circuit consists of close-loop bioamplifier with active DC-offset suppression and output stage of standard switched-capacitors (SC) circuit. As demonstrated by the simulation results, the readout circuit with CDS significantly suppresses low-frequency noise which focuses in the biopotential signal range from 10Hz to 10 KHz. The power spectrum is plotted in the low frequency range.