Realization of narrow-band SC-filters with low power consumption

Abstract

Synthesis of a narrow band switched-capacitor (SC) filter is discussed. Design is based on element simulation method when inductors of the filter prototype have been realized by 4-phase controlled single OpA SC-imitator that gives a possibility to decrease power consumption of the device. A six order Chebyshev type bandpass SC-filter with a middle frequency 1980 Hz and a frequency band 200 Hz has been synthesized and practically implemented in 0.35 mum CMOS process. The input referred RMS noise is 140 muV while HD2 and HD3 are -45, -53 dB consequently when the input signal amplitude is equal to about 90 mV. The total current consumption of the filter is 420 muA with 3.3 V voltage supply. The active area of the filter is 800 mum x 500 mum.