CMOS triode-transistor transconductor for high-frequency continuous-time filters

The paper describes a high-frequency fully-CMOS differential transconductor, which uses MOS transistors biased in the triode region with a constant drain-to-source voltage. The measured total harmonic distortion (THD) of the transconductor achieved using conventional 2 μm n-well CMOS technology, is -46 dB for a 1.2V_peak input signal at 10 MHz (supply voltage=5 V). A second-order continuous-time filter with the characteristic frequency tunable in the 10 MHz range is realised. It occupies a silicon area of 0.21 mm² and requires a power consumption of 12 mW. Its measured THD (in the low-pass configuration) is -50 dB with a 0.8V_peak differential input. Tuning capabilities are also shown