CMOS precision half-wave rectifying transconductor

A novel CMOS half-wave rectifying transconductor is presented. The proposed circuit utilizes a simple new cascode current subtracter which is obtained from conventional cascode current mirror by a judicious reconfiguration to yield additional subtrahend signal path. The simulated DC transfer characteristic is highly linear up to 1.5 V differential input voltage and the blunt corner at zero-crossing is 20 mV. The total harmonic distortions at 100 kHz with 1.5 Vp-p in the positive half cycle are better than -46.5 dB. The usable operating frequencies are up to 10 MHz with maximum peak-to-peak input voltage and 75 /spl mu/W power consumption.