A CMOS Weak Inversion RMS-to-DC Converter

In this paper a low-power current-mode RMS-to- DC converter is proposed. The proposed converter includes absolute value circuit, squarer/divider circuit, low-pass filterand square root circuit which employ CMOS transistors operating in a weak inversion region. The RMS-to-DC converter has low power consumption (<1.5 μW), low supply voltage (0.9V), wide input range (from 50 nA to 500 nA), low relative error (<3 %), bandwidth of 3.7 MHz and low circuitcomplexity. Comparing the proposed circuit with two other current-mode circuits shows that the former outperforms the latters in terms of power dissipation, supply voltage, and complexity. Simulation results by HSPICE show high performance of the circuit and confirm the validity of the proposed design technique.

Keywords:

RMS-to-DC converter , current-mode , weak inversion , low power , low voltage ,