Patent ID: 7521941

Claim:
A method for measuring a measurable capacitance, the method comprising the steps of: performing a first charge transfer process for a first number of times equal to at least two, wherein the first charge transfer process comprises the steps of: applying a first voltage to the measurable capacitance; and allowing the measurable capacitance to share charge through a passive impedance with a filter capacitance, wherein the passive impedance remains coupled to both the measurable capacitance and the filter capacitance throughout the applying and allowing steps of the first charge transfer process; performing a second charge transfer process for a second number of times equal to at least one, wherein the second charge transfer process comprises the steps of: applying a second voltage to the measurable capacitance; and allowing the measurable capacitance to share charge with the filter capacitance through the passive impedance, wherein the first voltage transfers charge in a first direction, and the second voltage transfers charge in a second direction opposite the first direction, and wherein the passive impedance remains coupled to both the measurable capacitance and the filter capacitance throughout the applying and allowing steps of the second charge transfer process; and determining a value of the measurable capacitance from the first charge transfer process and the second charge transfer process.