Highly linear wide tuning range CMOS transconductor operating in moderate inversion

A new CMOS transconductor with wide transconductance tuning range and very low distortion is presented. The input stage features a highly linear conversion of the input voltage into current form. Electronically programmable current mirrors able to operate in weak or moderate inversion provide a continuous transconductance tuning range of two decades without affecting the large input signal range available. Measurement results of a prototype fabricated in a 0.5/spl mu/m CMOS technology shows a THD of -66.5dB for a 100 kHz differential input of 2V/sub pp/.