Low noise, low distortion, high frequency, fully differential CMOS transconductor

Abstract

This paper describes a CMOS transconductance element based upon two differential pairs whose outputs are summed to give a linear transfer characteristic. The circuit has been simulated using a 2 μm process from MOSIS, and results show that with a single 5 V supply, bandwidth in excess of 300 MHz, THD below 0.7% for a 1 Vpk-pk differential input signal, and dynamic range in excess of 70 dB can be achieved.