摘要:
A method and system for adjusting characteristics of a relative humidity sensor in order to achieve a desired value of accuracy is presented. A relative humidity sensor charge balance circuit includes a series of sensing capacitors Cx1, Cx2 including a thin porous platinum top plate, a humidity sensitive polyimide dielectric, and two metal bottom plates on a semiconductor substrate; and two fixed oxide capacitances Cref, and C0. Changes in humidity affect the humidity sensitive dielectric thereby causing changes in the sensing capacitive value of the capacitive circuit. The charge in the sensing capacitor and the fixed capacitor C0 can be controlled separately by adjusting and/or trimming the supply voltage using a voltage trimmer; thereby the slope and offset of the relative humidity sensor circuit can be modified and controlled to particular desired values.
摘要:
A method and system for adjusting characteristics of a relative humidity sensor in order to achieve a desired value of accuracy is presented. A relative humidity sensor, charge balance circuit include a series of sensing capacitors Cx1, Cx2 comprising of thin porous platinum top plate, a humidity sensitive polyimide dielectric, and two metal bottom plates on a semiconductor substrate; and two fixed oxide capacitances Cref, and C0. Changes in humidity affect the humidity sensitive dielectric thereby causing changes in the sensing capacitive value of the said capacitive circuit. The charge in the sensing capacitor and the fixed capacitor C0 can be controlled separately by adjusting and/or trimming the supply voltage using a voltage trimmer; thereby the slope and offset of the relative humidity sensor circuit can be modified and controlled to particular desired values
摘要:
A vertical Hall effect apparatus, including methods thereof. A substrate layer can be provided upon which an epitaxial layer is formed. The epitaxial layer is surrounded vertically by one or more isolation layers. Additionally, an oxide layer can be formed above the epitaxial layer. A plurality of Hall effect elements can be formed within the epitaxial layer(s) and below the oxide layer, wherein the Hall effect elements sense the components of an arbitrary magnetic field in the plane of the wafer and perpendicular to the current flow in the hall element. A plurality of field plates can be formed above the oxide layer to control the inherited offset due to geometry control and processing of the vertical Hall effect apparatus, while preventing the formation of an output voltage of the vertical Hall effect apparatus at zero magnetic fields thereof.