Current-Mode Temperature Compensated Continuous-Time CMOS Transconductance-C Filter

In this paper a low voltage low power current-mode continuous-timelow-pass filter is presented. The current-integrator is constructedof a multi-output linearized transconductance element drivenby a balanced transimpedance amplifier. A 1 MHz third order ellipticlow pass filter is designed and fabricated with the proposedcurrent-mode integrator. The measurements show capability ofoperation with down to a 3 V supply voltage. The measured currentconsumption is 850 µA at room temperature andthe dynamic range is 66 dB. The distortion of the filter is below50 dBc with peak signal levels up to twice the quiescent currentlevel and with the refined designs even lower distortion is expected.The filter uses a CMOS-current reference for temperature andprocess variation stabilization with a measured corner frequencytemperature coefficient of −100 ppm/K.