Patent ID: 8564301

Claim:
The method of determining a capacitance of a device having a first terminal and a second terminal, comprising: connecting a first terminal of a capacitor having a known capacitance to the first terminal of the device; applying an AC voltage having a first amplitude to the first terminal of the device and the first terminal of the capacitor; measuring an instantaneous current through the capacitor while applying the AC voltage having the first amplitude to the first terminal of the capacitor; measuring an instantaneous current through the device while applying the AC voltage having the first amplitude to the first terminal of the device; determining a first voltage across the device as a function of time while the AC voltage having the first amplitude is applied to the first terminal of the device; computing a first capacitance of the device as a function of time by multiplying the capacitance of the capacitor by the ratio of the instantaneous current through the device to the instantaneous current through the capacitor during application of the AC voltage having the first amplitude; determining a first capacitance of the device as a function of voltage based on the first capacitance as a function of time and the first voltage across the device as a function of time; and outputting data of the first capacitance of the device as a function of voltage.