0.9V low-power switched-opamp switched-capacitor bandpass filter for electroneurography acquisition systems

A 0.9V fully differential switched-opamp-based sixth-order switched-capacitor bandpass filter, which has frequency response centred at 1.118kHz with a Q of 0.235 and power saving by a proposed low-power biquad structure, is designed for electroneurography acquisition systems. It is implemented in a 0.18m CMOS technology with a normal threshold voltage of 0.48V. The measured peak signal-to-noise ratio is 52dB at 1kHz sinusoid wave with input amplitude of 1V_pp. In addition, the measured power-supply rejection ratio and common-mode rejection ratio are >40dB in the desired bandwidth and have peak values of 70 and 67dB, respectively. A dynamic range of 50dB for total harmonic distortion of 3 is obtained while dissipating 262W and occupying a chip area of 0.35mm².