Parasitic capacitance cancellation in capacitive measurement
First Claim
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1. An integrated circuit for measuring an inductance of a structure, wherein said integrated circuit comprises:
- charge transfer circuitry for transferring charge during each of a plurality of measurement cycles from said structure to a reference capacitor, and wherein the charge accumulated in the reference capacitor is reduced during every cycle in the inductance measurement by a predetermined amount of charge, and wherein the charge being transferred for measurement is scaled using at least one current mirror structure.
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Abstract
An integrated circuit compensates for parasitic capacitance in a capacitive measuring apparatus wherein a capacitance measurement is done by repeatedly transferring charge from a capacitor to be measured to a reference capacitor.
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Citations
17 Claims
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1. An integrated circuit for measuring an inductance of a structure, wherein said integrated circuit comprises:
- charge transfer circuitry for transferring charge during each of a plurality of measurement cycles from said structure to a reference capacitor, and wherein the charge accumulated in the reference capacitor is reduced during every cycle in the inductance measurement by a predetermined amount of charge, and wherein the charge being transferred for measurement is scaled using at least one current mirror structure.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- 13. A method to measure an inductance of a structure, wherein said method comprises the steps of transferring charge during each of a plurality of cycles of the measurement from said structure to a reference capacitor, of reducing the amount of charge accumulated in said reference capacitor by a predetermined amount and of scaling the charge being transferred by using at least one current mirror structure.
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