Accuracy Analysis of the LCR Meter-Based Method for C-V Characterization of a Capacitor

The capacitance-voltage (C-V) characterization of capacitors and power semiconductor devices (MOSFETs and diodes) is crucial for circuit analysis and loss modeling. This paper discusses an LCR meter-based capacitive coupling method for C-V characterization. It requires an LCR meter and a few inexpensive passive components. However, the unaccounted effects of the parameters, such as blocking capacitance, filtering inductance, parasitic inductance, or power supply impedance can significantly affect the accuracy of the measuring circuit. In this paper, these effects are analyzed, and the expected error is described analytically. Thus, the measuring circuit can be designed using the derived formulas to achieve the targeted accuracy and frequency range. The measuring circuit with the measuring range of 10 kHz-1 MHz with less than 1% error was designed using the derived analytical equations and validated experimentally.