A compact tunable CMOS transconductor with high linearity

A novel CMOS linear transconductor is presented. The use of simple and accurate voltage buffers to drive two MOS transistors operating in the triode region leads to a highly linear voltage-to-current conversion. Transconductance gain can be continuously and precisely adjusted using dc level shifters. Measurement results of a balanced transconductor fabricated in a 0.5-μm CMOS technology show a total harmonic distortion of -54 dB at 100 kHz for an 80-μA peak-to-peak output, using a supply voltage of 2 V. It requires 0.07-mm² of silicon (Si) area and features 0.96 mW of static power consumption.