A Low Power and Area-efficient Fully Differential Chopper Amplifier Suitable for EEG Recording

This paper presents a fully differential chopper amplifier with low power and ultra-low area consumption which consumes very low power. To reduce the area consumption, this circuit is designed with cross-coupled differential amplifier. According to the specific feature of designed chopper amplifier, the input transistors occupied small area. Furthermore, this structure has inherently high PSRR and high CMRR. Accordingly, this chopper amplifier has no need for additional circuit to boost the CMRR and PSRR which significantly helped to reduce total area consumption. The circuit is designed in $0.18 \mu \mathbf{m}$ CMOS process. The proposed amplifier has 42.5dB DC gain so that the total power consumption is $2 \ \mu \mathbf{w}$ and the total input referred noise is $1.5 \mu \text{V}_{\text{rms}}$ from 1 to 250 Hz with flicker noise corner lower than 2 Hz. The total active area consumption is 0.0015 mm².