A CMOS continuous-time Gm-C filter and programmable gain amplifier for WPAN receivers

This paper describes a low-voltage and low-power channel selection analog front end with continuous-time low pass filters and highly linear programmable-gain amplifier(PGA). The filters were realized as balanced Gm-C biquadratic filters to achieve low current consumption. High linearity and constant wide bandwidth are achieved by using a new transconductance(Gm) cell. The POA has a voltage gain varying from 0 to 65 dB, while maintaining a constant bandwidth. A filter tuning circuit that requires an accurate time base but no external components is presented. Both the filter and PGA were implemented in a 0.18um 1P6M n-well CMOS process. They consume 3.2 mW from a 1.8 V power supply and occupy an area of 0.19 mm².