A low-voltage low-power high precision digitally tunable transconductance rectifier

This paper presents an ultra-low-voltage low-power high precision digitally tunable transconductance rectifier and its applications as a RMS-to-DC converter and amplitude shift keying (ASK) demodulator. Using the high impedance voltage-mode input stage with wide input common mode voltage range, the full-wave rectifier achieves both high accuracy and easy interface. Measured results of the RMS-to-DC converter and ASK demodulator show that, the proposed rectifier achieves robust performance under wide supply range (from 0.5 V to 1.8 V) and frequency range (from DC to 25 MHz).