Monolithically compatible impedance measurement
US6456096B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | May 8, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A monolithic sensor includes a reference channel and at least one sensing channel. Each sensing channel has an oscillator and a counter driven by the oscillator. The reference channel and the at least one sensing channel being formed integrally with a substrate and intimately nested with one another on the substrate. Thus, the oscillator and the counter have matched component values and temperature coefficients. A frequency determining component of the sensing oscillator is formed integrally with the substrate and has an impedance parameter which varies with an environmental parameter to be measured by the sensor. A gating control is responsive to an output signal generated by the reference channel, for terminating counting in the at least one sensing channel at an output count, whereby the output count is indicative of the environmental parameter, and successive ones of the output counts are indicative of changes in the environmental parameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.