A New True RMS-to-DC Converter in CMOS Technology

Authors: H. Asiaban, E. Farshidi

Abstract:

This paper presents a new true RMS-to-DC converter circuit based on a square-root-domain squarer/divider. The circuit is designed by employing up-down translinear loop and using of MOSFET transistors that operate in strong inversion saturation region. The converter offer advantages of two-quadrant input current, low circuit complexity, low supply voltage (1.2V) and immunity from the body effect. The circuit has been simulated by HSPICE. The simulation results are seen to conform to the theoretical analysis and shows benefits of the proposed circuit.

Keywords: Current-mode, squarer/divider, low-pass filter, converter, translinear loop, RMS-to-DC.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1333006

References:

[1] S. A. P .Haddad, S. Gieltjes, R. Houben, and W. A. Serdijn, "An ultra low-power dynamic translinear cardiac sense amplifier for pacemakers, " In IEEE Int. Symp. Circuits Syst., ISCAS-03, vol. 5, pp. V-37-V-40, May 2003.
[2] Analog Devices, AD636 Data Sheet, "Low level True RMS-to-DC converter," Available: http://www.selectronic.fr/ includes_ selectronic/pdf/Analog_Device/AD636JH.pdf.
[3] J. Mulder, A. C. V. D. Woerd, W. A. Serdijn,and A. H. M. V. Roermund, "An RMS-DC converter based on the dynamic translinear principle," IEEE J. Solid-State Circuits, vol. 32, no.7, pp. 1146-1150, Jul. 1997.
[4] A. J. Lopez-Martin, and A. Carlosena, "A 1.5V current-mode CMOS RMS-to-DC converter," Analog Integrated Circuits Signal Process., vol. 36, pp. 137-143, 2003.
[5] C. A. DE La Cruz-Blas, A. J. Lopez-Martin, A. Carlosena and J. Ramirez-angulo, "1.5v current-mode CMOS true RMS-DC converter based on class-AB transconductors," IEEE Trans. Circuits Syst. II, Express Briefs, vol. 52, no. 7, pp. 376-379, Jul. 2005.
[6] E. Farshidi, S. M. Sayedi, "A 1.2V current-mode true RMS-DC converter based on the floating gate MOS translinear principle," Microelectronics Journal, Elsevier, vol. 39, no. 2, pp. 293-298, Feb. 2008.
[7] E. Farshidi and S. M. Sayedi, "A micropower multi decade dynamic range current-mode true rms-to-dc," MWSCAS-07, Proceedings of the 50th IEEE Circuits and Systems International Midwest Symposium, pp. 1493-1496, Aug. 2007.
[8] E. O.Rodriguez-villegas and H. Barnes, "solution to trapped charge in FGMOS transistors," Electron. Lett. , vol. 39, pp. 1416-1417, Sep. 2003.
[9] Bin-Da Liu, Chuen-Yau Chen and Ju-Ying Tsao, "A modular currentmode classifier circuit for template matching application," IEEE. Trans. Circuits Syst. II, Analog Digit. Signal Process., vol. 47, no. 2, pp. 145- 151, Feb. 2000.
[10] C. Psychalinos and S.Vlassis, "A systematic design procedure for square-root -domain circuits based on the signal flow graph approach," IEEE Trans .Circuits Syst. I, Fundam. Theory Appl., vol. 49, no. 12, pp. 1702-1712, Dec. 2002.
[11] C. A. DE La Cruz-Blas and A. Lopez, "A Novel Two Quadrant MOS Translinear Squarer-divider Cell," In IEEE Int. Symp. Circuits Syst., ISCAS-08, pp. 5-8, May 2008.
[12] R. Frey, "Current mode class-AB second order filter," Electron. Lett. , vol. 30, pp. 205-206, Feb. 1994.