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.<<ETX>>

[1]  Ashok Nedungadi,et al.  Design of linear CMOS transconductance elements , 1984 .

[2]  R. Castello,et al.  A high-performance micropower switched-capacitor filter , 1985, IEEE Journal of Solid-State Circuits.

[3]  C. F. Rahim,et al.  Sampled analog filtering using switched capacitors as resistor equivalents , 1977 .

[4]  Alan V. Oppenheim,et al.  Discrete-Time Signal Pro-cessing , 1989 .

[5]  K. Martin.  Improved circuits for the realization of switched-capacitor filters , 1980 .

[6]  M. Banu,et al.  Fully integrated active RC filters in MOS technology , 1983, 1983 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.

[7]  C. Duvvury,et al.  A guide to short-channel effects in MOSFETs , 1986, IEEE Circuits and Devices Magazine.

[8]  J. Quartly,et al.  Gyrator video filter IC with automatic tuning , 1980, 1980 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.

[9]  Mohammed Ismail,et al.  High Frequency CMOS Transconductors , 1993 .

[10]  J. Friend,et al.  STAR: An active biquadratic filter section , 1975 .