Analog CMOS tesla-volt multiplier circuit

Abstract

This paper describes a simple CMOS analog circuit that performs the multiplication of an external bipolar voltage, e, by an applied magnetic field B. The circuit uses an arrangement of split-drain MOS transistors operating in the saturation region to produce an output difference current that is proportional to (B/spl times/e). If the external voltage e is a fraction of the mains voltage and B is produced by the corresponding current, the output signal is a measure of the instantaneous power. Measurements of a test circuit, which was built with discrete transistors fabricated in CMOS 0.8 /spl mu/m technology, have shown that a monolithic mixed-signal solution for single phase power consumption metering based on this concept is technically feasible.