A 4.1mW 79dB-DR 4th-order Source-FollowerBased Continuous-Time Filter for WLAN Receivers

Abstract

Using a composite source-follower with positive feedback to synthesize complex poles, a single-branch CMOS biquad achieves large linearity at low overdrive voltage, saving power. In 0.18mum CMOS with a 1.8V supply, a 41h-order 10MHz filter for WLAN applications achieves 17.5dBm IIP3 and mu40dB HD3 for a 600mVpp_diff input signal amplitude. A 24muVrms noise gives a 79dB DR while drawing 2.25mA from 1.8V