A design strategy for VHF filters with digital programmability

In this paper we report 2nd and 3rd-order G_m-C filters based on fully-balanced pseudo-differential continuous-time transconductors for applications in low-voltage systems over the VHF range. By using a 0.35 mum standard CMOS process, low-pass filter approximations have been implemented with a cut-off frequency programmability over the 40-200 MHz range, which confirm the feasibility of the proposed strategy in applications such as data storage systems and IF strips. The filters consume less than 4.8 mW per pole at 45 MHz from a 2V supply. The measured dynamic range was better than 53 dB at THD of 1% for all filters. The maximum active chip area is 0.025 mm² per pole