DESIGN TECHNIQUES FOR HIGH-FREQUENCY CMOS SWITCHED-CAPACITOR FILTERS USING NON-OP-AMP-BASED UNITY-GAIN AMPLIFIERS

A fully differential non-op-amp-based unity-gain amplifier (UGA) is proposed, whose 3-dB frequency can be as high as 250 MHz in 3.5-mu-m p-well CMOS technology. Suitable predistortions can be introduced under the aid of CAD tools to reduce the parasitic effects. Experimental results have successfully proven the capability of the proposed structures in the realization of high-frequency switched-capacitor filters over the megahertz range. Filter accuracy can be further enhanced by using the tunable-gain UGA, which enables tuning on filter parameters.