A low-power Gm-C low pass filter for mobile applications

This study presents a high performance complementary metal oxide semiconductor (CMOS) transconductor used in a multimode channel selection filter for mobile applications. The design employs a voltage to current (V-I) converter and a two quadrant current multiplier. Cascoded flipped voltage follower (CASFVF) is used as an input stage in class AB pseudo differential pair to perform V-I conversion. Current multipliers are used to linearise output from V-I converter and provide additional tuning ability to transconductor. A second - order Butterworth low pass filter (LPF) is designed with proposed transconductor and simulated using TSMC 0.35-mu m CMOS technology in H-spice in synopsis tool. LPF consumes very low power (0.2 mW) and provides a Wide tuning range (200 K.Hz - 3.1 MHz).