A Micropower Multi Decade Dynamic Range Current-Mode True RMS-to-DC Converter

A log-domain current-mode true RMS-to-DC converter based on a novel synthesis of a simplified current-mode low pass filter and a two-quadrant squarer/divider is presented. The circuit employs floating gate MOS (FG-MOS) transistors operating in weak inversion region. The converter features low power( < 1.5uW), low supply voltage (0.9V), two quadrant input current, immunity from body effect, low circuit complexity, and very wide input dynamic range(0.7nA to 350nA). Simulation results by HSPICE show high performance of the circuit and confirm the validity of the proposed technique.