METHOD AND SYSTEM FOR ADJUSTING CHARACTERISTICS OF INTEGRATED RELATIVE HUMIDITY SENSOR

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.