A low-noise, high-precision chopper instrument amplifier for EEG signal amplification

In this paper, a low-noise, high-precision chopper instrumentation amplifier (IA) for EEG signal acquisition and amplification is designed. To achieve low-noise performance, chopper modulation is applied. A common-mode compensation structure is designed for chopper modulation application environment, which makes the overall performance of IA more stable. At 1000x amplification, the equivalent input noise is only 25.3nV/sqrt(Hz)@10Hz, CMRR is 155.3dB, PSRR is 167.5dB, offset is only 10.26uV, and input impedance is 10.7GΩ@100HZ.