Low-Power CMOS Bandpass Filter for Application of Cochlear Prosthesis

Abstract

A CMOS Gm-C filter based on operational trans conductance amplifiers (OTA5) with low power and tuning ability for biomedical applications is proposed in this paper. The OTA works in the weak inversion region. The transconductance can be tuned by changing the bias current. A fourth-order Butterworth LC ladder Gm-C bandpass filter is implemented by 0.18 tm CMOS process. The supply voltage of the OTA-C filter can be as low as 0.65 V for minimum power dissipation. The power consumption is 61 nW for a sinusoidal input signal of 300 Hz 100 mV(PP) and 1 V supply voltage and total harmonic distortion is 50.23 dB. The active area is 0.04 mm(2).