Apparatus for detecting the failure of a sensor

摘要

Provided are two monitor circuits for monitoring two input signals Va and Vb of an input stage differential amplifier, respectively, and two monitor circuit for monitoring two output signals Vc and Vd of the input stage differential amplifier, respectively. When failure occurs at the bridge circuit of a sensor element or at the input stage differential amplifier, the monitoring units or the monitoring units detect abnormality, which makes it possible to detect the failure of the sensor element or the input stage differential amplifier. Therefore it is possible to detect failure such as a disconnection or a short circuit of the bridge circuit of the sensor element and failure which has occurred at the amplifier for amplifying outputs of the sensor element.