Bulk linearized CMOS differential pair transconductor for continuous-time OTA-C filter design

In this paper, the MOS differential pair driven simultaneously from gates and bulk terminals is described. An approximated analytical solution of the voltage to current transfer function has been found for the proposed circuit. Four possible combinations of gate and bulk connections of the input signal are presented. Basing on the configuration giving the best linearity, the operational transconductance amplifier (OTA) has been designed and compared, by computer simulations, to the amplifier utilizing the gate driven classic MOS pair. 3rd order filters using the OTAs with linearized and simple MOS pair have been designed and the resulting parameters have been compared. Linearization through the presented simultaneous use of gate and bulk terminals seems to be useful for low voltage applications.