Capacitive temperature compensation for a pressure sensor

摘要

The undesired temperature variation of a capacitive pressure sensing element (10) having a positive temperature coefficient of capacitance (TCC) is compensated by a series resistor R and compensating capacitor (Cc) connected in parallel to the pressure sensing capacitor (Cx). The compensating capacitor and presssure sensing element have opposite polarity temperature coefficients of capacitance, and the magnitude of the resistor is selected such that its resistive impedance is nonnegligible and is comparable to the magnitude of the capacitive reactance of the pressure sensing capacitor or compensating capacitor at a predetermined operative frequency of an electrical signal applied to and/or determined by the pressure sensing and compensating capacitors.