Semiconductor pressure sensor
AssigneeHoneywell Inc.
InventorRichard H. Frische
Life of this patent
Estimating the term…
Abstract
Pressure sensor having a silicon diaphragm chip. The diaphragm in the chip is less than 200 mils in diameter and has an ultrasonic resonant frequency that varies with pressure exerted on it. The chip has resistors with values that change with fluctuation of the chip. The changing resistor values are fed to a supporting electronics that detect the resonant frequency of the diaphragm and indicate measurement of the pressure exerted on the diaphragm. The supporting electronics feed back a signal corresponding to the detected resonant frequency for a sensed pressure to a piezoelectric device that drives the diaphragm to sustain its vibration.
Claims11
A semiconductor pressure sensor comprising:
- a header having a pressure port;
- a piezoelectric device, having a center port, attached to said header at an end of the pressure port;
- a back plate, having an orifice, attached to said piezoelectric device;
- a diaphragm chip attached to said plate;
- and
- a cover attached to said header, thereby completing an enclosure of said piezoelectric device, back plate and diaphragm chip in a volume bordered by said header, pressure conducting film and said cover.
A semiconductor pressure sensor comprising:
- a monolithic semiconductor chip having a diaphragm that vibrates at a resonant frequency which changes due to a variable displacement of said diaphragm, the displacement being varied in response to a direct application of an ambient pressure to said diaphragm, and having impedance means for indicating the displacement of said diaphragm;
- transducer means situated in proximity of said monolithic semiconductor chip for sustaining vibration of said diaphragm;
- detector means, connected to said impedance means, for detecting the resonant frequency of said diaphragm;
- and
- supporting electronics means, connected to said transducer means and to said detector means, for converting the resonant frequency of said diaphragm into a measurement of the ambient pressure upon said diaphragm and for providing a feedback signal to drive said transducer means.
Dependencies are inferred from the claim text.