CMOS filter with wide digitally programmable VHF range

A novel approach is presented for programmable filtering over the VHF range based on fully-balanced pseudo-differential continuous-time transconductors for applications in low-voltage systems. An example third-order G(m)-C lowpass Butterworth filter using the proposed trans-conductor and accumulation MOS capacitors has been implemented using an AMS 0.35 mu m CMOS process, achieving -3 dB cutoff frequencies ranging from 40 to 200 MHz. The active chip area is 0.06 mm(2) per pole.