An Elegant Method for Measuring MOST Drain-Source Conductance in the Saturated Current Region

An elegant method is presented for measuring the drain-source conductance of an MOST operating in the saturated current region. The measuring setup allows measurement of the drain-source conductance ranging from 10-3 to 1 mU with a sensitivity of less than 0.1 percent at a frequency of 1 kHz and also measurement of the variation rate in the drain-source conductance in excess of 0.2 percent. The lower limit to the measuring range of the drain-source conductance is widened from 10-3 to 10-5 mU when an FET preamplifier is used as a front end of a comparator in which signal voltage proportional to the drain-source conductance is compared with the reference voltage. This lower conductance range can be used in measuring the drainsource conductance of an MOST operating near the cutoff point.