CMOS TRIODE-TRANSISTOR TRANSCONDUCTOR FOR HIGH-FREQUENCY CONTINUOUS-TIME FILTERS

The paper describes a high-frequency fully-CMOS differential transcond uctor, which uses MOS transistors biased in the triode region with a c onstant drain-to-source voltage. The measured total harmonic distortio n (THD) of the transconductor achieved using conventional 2 mum n-well CMOS technology, is -46 dB for a 1.2V(peak) input signal at 10 MHz (s upply voltage = 5V). A second-order continuous-time filter with the ch aracteristic frequency tunable in the 10 MHz range is realised. It occ upies a silicon area of 0.21 mm2 and requires a power consumption of 1 2 mW. Its measured THD (in the low-pass configuration) is -50 dB with a 0.8V(peak) differential input. Tuning capabilities are also shown.