A programmable 1.8-18 MHz high-Q fully-differential continuous-time filter with 1.5-2 V power-supply

A simple CMOS current-mode filter is presented. Its basic building block is a transconductor. It is comprised of a MOS transistor driver operating in the triode region cascoded with a MOS transistor current source at the output. This circuit can be employed in high-frequency continuous-time current-mode filters using a /spl plusmn/1 V power supply while dissipating less than 1 mW of power. To illustrate the methodology a second-order fully-differential bandpass filter with programmable f/sub 0/ and Q tuning is demonstrated. This filter dissipates less than 0.5 mW/pole with a /spl plusmn/1 V power supply and occupies an area of 0.6 mm/sup 2/ using a MOSIS Orbit 2 /spl mu/m CMOS technology.<<ETX>>