A ultra low power, wide input range MICS band channel selection filter on 65 nm CMOS

Abstract

This paper proposes a low power MICS band receiver channel selection filter on 65 nm CMOS for implantable biomedical devices. This 5th-order elliptic OTA-C bandpass filter utilizes sub-threshold inverter based OTAs. In order to broaden input range of the filter, the first OTA stage is linearized by using the active-error feedforward technique. The overall filter only consumes 300 μA DC current under 1 V supply, while having an input range up to 0.6 Vpp. The total harmonic distortion (THD) is -58 dB for 1.3 MHz input signal at 0.5 Vpp swing. As a MICS band channel selection filter, it has 300 kHz bandwidth and exhibits more than 45 dB attenuation to the ajacent channel. By using NFET capacito..