A 0.18-μm-CMOS low-power reconfigurable low pass filter for multi-standard receivers

This paper presents a 4^th order continuous-time low-power reconfigurable low pass filter (LPF) using active-G_m-RC structure for multi-mode multi-standard communications. Programmable OTAs (operational transconductor amplifier) and R-C arrays are employed to realize the reconfiguration of cut-off frequencies, power consumption, and linearity of the LPF. Designed and fabricated in 0.18 μm CMOS technology, the proposed LPF achieves a measured reconfigurable cut-off frequency from 1.39 to 10.6 MHz with the consumed power from 0.45 to 1.35 mW. The measured dc gain is 17.3 dB and the 1-dB compression point is -9.7 dBV_pp. The proposed LPF occupied an area of 0.64 mm² including testing pads.