A Blocker-Vigilant Channel-Select Filter with Adaptive IIP3 and Power Dissipation

Abstract

A dynamic biasing scheme that reduces the average dc power of channel-select filters is presented. An adaptive IIP3, 5th-order Butterworth low-pass filter is implemented in a 0.18mum CMOS process with a 1.8V supply voltage. The filter quiescent current is 1.2mA, with a -5dBV out-of-channel IIP3. With a blocker level of -13dBV, the supply current increases to 2.7mA and the IIP3 increases to +20dBV