Measuring chip-to-chip capacitance differentials by demodulating signals over a capacitance bridge
US7425836B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2006 |
| Grant date | Sep 16, 2008 |
| Priority date | — |
| Expiry date | Mar 21, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method for determining capacitance, a first time-varying signal is driven on a first terminal of a first capacitor and a second time-varying signal is driven on a first terminal of a second capacitor, where the first time-varying signal and the second time-varying signal have a pre-determined phase relationship with each other.These signals are received on second terminals of the first capacitor and the second capacitor and demodulated using a periodic signal to produce demodulated signals. This periodic signal has the same fundamental frequency as the first time-varying signal and the second time-varying signal. A DC component in the demodulated signals is then determined by filtering the demodulated signals, and the sign of the DC component is used to determine a relative capacitance of the first capacitor and the second capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.