A translinear-based true RMS-to-DC converter using only npn BJTs

A true rms-to-dc converter based on the explicit computation technique is proposed in this paper. Since the scheme utilizes translinear principle circuits to realize current-mode squarer, averaging and square root circuits, only npn bipolar junction transistors are required. The conversion circuit has wide-band frequency response and can be operated with single supply voltage at 2 V. PSPICE simulation and experimental results show good agreement with the theoretical predictions.