Semiconductor acceleration detecting device

摘要

A semiconductor acceleration system for detecting acceleration by outputting an electrical signal includes a diagnostic circuit for detecting failures in an output amplifier of the system. The system includes strain gauge resistors on a semiconductor substrate and connected in a bridge circuit. The output terminals of the bridge circuit are connected to an output amplifier. The diagnostic circuit includes two constant current sources producing different constant current flows and respectively connected to the two output terminals of the bridge circuit. When a switch is closed connecting the constant current sources to ground so that the constant currents flow through two of the strain gauge resistors, the output signal of the amplifier is observed. The output signal with the switch open and closed discloses the existence of a fault in the output amplifier circuit and the location of that fault.