A balanced 0.9- mu m CMOS transconductance-C filter tunable over the VHF range

A balanced 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 from a nominal value near 1 to approximately 100 with 30-40-dB dynamic range. 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. Active area is 0.029 mm/sup 2/ and power consumption is 8-12 mW with a 5-V power supply. >

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