Sensing circuit and method for diagnosing open and short circuit conditions of a sensor

摘要

A sensing circuit (50) for detecting open and short circuit conditions in sensors (20) is provided. The sensing circuit (50) includes switching circuitry ( t1 ,t1-t5), a voltage supply (VBIAS), a test capacitor (32), and an operational amplifier (30). The switching circuitry ( t1 ,t1-t5) is electrically coupled to the voltage supply (VBIAS), test capacitor (32), operational amplifier (30), and a sensor (20). The sensing circuit (50) is configured to provide for a normal operating mode in which the sensing circuit (50) provides an output indicative of a voltage across the sensor (20), and a charging mode in which the test capacitor (32) is coupled to the sensor (20) and operational amplifier (30) and charged to a steady state, and in which the output (35) of the operational amplifier (30) is a function of the test capacitor (32) capacitance and the capacitance of the sensor (20). A method for detecting open and short circuit conditions in sensors (20) is also provided.