A Low-Power Stable Wideband Current Source for Acupuncture Point Skin Impedance Measurements

摘要

A low-power stable wideband current source for acupuncture point skin impedance measurements has been designed employing a differential architecture and negative feedback. The circuits extend bandwidth to 1 #x2009;MHz, reducing harmonic distortion to 0.24 #x0025; at 1 #x2009;MHz. The output impedance is 37 #x2009;M #x2126; at 100 #x2009;kHz and 11 #x2009;M #x2126; at 1 #x2009;MHz. The stability of the output current of the current source when connected to different loads is below 0.1 #x0025; at frequencies up to 500 #x2009;kHz and increases to 0.74 #x0025; at 1 #x2009;MHz. The circuit was manufactured in a 0.13- #x3bc; m CMOS technology and measured results are presented. The area of the current source is 0.09 #x2009;mm~(2) and its consumption is 1.2 #x2009;mW. It is intended for low-power acupuncture point skin impedance measurements.