Semiconductor pressure sensor utilizing capacitance change
US6631645B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 1, 2000 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Sep 1, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/125
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An S/N ratio of an output of a semiconductor pressure sensor is improved, the sensor being of an electrostatic capacitance type pressure sensor for generating an output based upon a ratio between capacitances of a pressure sensitive capacitance element and a reference capacitance element. This semiconductor pressure sensor has: a pressure sensitive capacitance element having an electrostatic capacitance Cs changing with a pressure to be detected; a reference capacitance element having an electrostatic capacitance Cr not changing with the pressure; and a unit for detecting the pressure by outputting a signal corresponding to a ratio between the capacitances Cs and Cr, wherein an initial value Cr0 of the capacitance Cr and an initial value Cs0 of the capacitance Cs are defined by 1.2<Cr0/Cs0<1.8. The Cr0/Cs0 ratio is adjusted by changing the electrode area or the like of both the elements. In this manner, it is possible to obtain a large pressure gauge output &Dgr;V, lower an amplification factor of the amplifier, and provide a high precision of the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.