A CMOS biquad at VHF

A differential transconductance-C biquad implemented in the digital subset of a 0.9- mu m CMOS process operates at frequencies up to 450 MHz and Q-factors to approximately 100 with SNR (signal-to-noise ratio) in the range of 35-45 dB. By switching in capacitors and adjusting control voltages it can be tuned to below 30 MHz, demonstrating the capability of operating over the entire VHF range. The active area is 0.029 mm/sup 2/ and power consumption is 30 mW.<
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