REALIZATION OF SILICON EFFICIENT AND PARASITIC INSENSITIVE SC FILTERS AND EXAMINE THEIR PERFORMANCE CHARACTERISTICS

Abstract

Two types of 2nd-order switched capacitor (SC) building blocks have been chosen. to realize silicon efficient SC filters. The derivation of their z-domain equivalent admittances, based on the principle of charge conservation is given. A 2nd-order bandpass filter and a 3rd-order lowpass filter using such building blocks have been realized with -discrete components. Effect of parasitic capacitances on system'-s performance has also been studied and the frequency, response of. filters with and without parasitic capacitances have been compared. A fully parasitic insensitive SC biquad has also been compared with parasitic sensitive SC biquad. The results indicate that the shifting of 3dB frequencies due to parasitic capacitances could be taken care of by appropriately shifting the poles of the system transfer function.