Method for determining capacitance of a device

A method of determining a capacitance of a device having a first terminal and a second terminal, comprising:

• connecting the first terminal of the device to a first channel of an oscilloscope;
• connecting a first terminal of a capacitor having a known capacitance to the first terminal of the device;
• connecting a second terminal of the device to a second channel of the oscilloscope;
• connecting a second terminal of the capacitor to a third channel of the oscilloscope;
• supplying an alternating current (AC) voltage to the first terminal of the device and the first terminal of the capacitor;
• determining a voltage as a function of time across the device while supplying the AC voltage from information collected by the first channel of the oscilloscope;
• determining a current through the device from information collected by the second channel of the oscilloscope while supplying the AC voltage to the first terminal of the device;
• determining a current through the capacitor from information collected by the third channel of the oscilloscope while supplying the AC voltage to the first terminal of the capacitor;
• computing a capacitance of the device as a function of time by multiplying the capacitance of the capacitor by the ratio of the current through the device to the current through the capacitor;
• determining a capacitance of the device as a function of voltage based on the computed capacitance as a function of time and the voltage across the device as a function of time;
• and
• outputting data of the capacitance of the device as a function of voltage.