Novel pseudo RMS current converter for sinusoidal signals using a CMOS precision current rectifier

A very simple pseudo RMS-to-DC current converter for sinusoidal signals is described. The most salient feature of the circuit is that it uses a CMOS precision current rectifier consisting of only two transistors and thus operates throughout in the current domain. The full-wave rectifier was built using CD4007 devices and tested. It was observed that the transfer curve is sharp even at low nanoampere input levels. The converter is expected to work up to 100 kHz.