Patent attributes
An absolute pressure sensor includes a sense die with a reference chamber on a top side thereof. The reference chamber comprises a precisely fabricated beam that limits the travel of a diaphragm. The beam can be positioned in a cap or cover member of the sense die, thereby allowing the sense die diaphragm to move freely for a particular distance. Over this distance, the sense die will have one sensitivity. When the sense die is pressurized to a certain point, the diaphragm moves until it contacts the beam member in the cap or cover. When the diaphragm hits the beam, the sensitivity of the sense die changes, thereby allowing a smaller voltage out for the greater pressure in. Such an arrangement permits the sensor to provide a function that accurately measures low pressure and measures a higher pressure without utilizing a linear scale.
