Patent ID: 9229040
Filing Date: 2016-01-05
CPC Classification: G01D,G01R

Claim Text:
1. A disconnection detection circuit for a bridge circuit, comprising: a sensor element resistor whose resistance value varies depending on a physical quantity; a bridge circuit composed of a plurality of resistors including the sensor element resistor, the bridge circuit being supplied with a voltage between a power terminal and a ground terminal, wherein a power terminal voltage is higher than a ground terminal voltage; an output terminal through which an intermediate voltage of the bridge circuit is fetched into outside; and a bridge output detection circuit that detects the intermediate voltage fetched through the output terminal, the disconnection detection circuit for a bridge circuit being connected to the output terminal, wherein the disconnection detection circuit comprises: a conducting means that causes a current to flow into the output terminal of the bridge circuit; a potential difference detection means that detects a potential difference between the potential at the output terminal of the bridge circuit and a predetermined potential and detects a disconnection; a switching means that, when the disconnection detecting means detects a disconnection, fixes the output of the bridge output detection circuit to a supply voltage or ground voltage, the conducting means is connected to the output terminal, and that the voltage at the power terminal of the bridge circuit is a low potential with respect to the predetermined potential.