Load Drive Circuit

摘要

A load drive circuit incorporated into an onboard electronic control device, the load drive circuit housing a diagnosis circuit for diagnosing load abnormalities, wherein diagnosis circuit failures are detected without affecting load drive control. When a failure has occurred in the diagnosis circuit, vehicle operation is not affected because the diagnosis circuit does not have a function for controlling the vehicle, and there may be cases in which occupants riding an the vehicle do not notice the failure. Additionally, when a failure has occurred in the diagnosis circuit, the occurrence of the failure cannot be detected even by a vehicle control system as long as there is no function for detecting occurrences of failure in the diagnosis circuit. Specifically, when a failure has occurred in the diagnosis circuit, there is a possibility that the failure is unrecognizable to occupants and undetectable by a vehicle control system. When there is no need for the diagnosis circuit to diagnose load abnormalities, a determination of whether or not the diagnosis circuit is failing is made by sending a pseudo abnormality signal to the diagnosis circuit and confirming whether the diagnosis circuit can detect the sent pseudo abnormality signal as a failure.

主权项

1. A load drive circuit comprising:
a load drive element that drives a load which is mounted on a vehicle; a detection unit that measures a physical quantity which is a detection target and outputs the measured physical quantity as a detection signal so as to diagnose abnormality of the load; and a diagnosis circuit that diagnoses whether or not abnormality occurs in the load, based on the signal which is outputted from the detection unit, wherein, during an operation of the vehicle, whether or not abnormality occurs in the load is diagnosed.