External load diagnostics circuit to detect electrical faults

The purpose of load-diagnostic circuitry is to diagnose potential faults which may occur in electrical circuitry throughout an automobile. One example application of this circuitry is to support eCall system functionality. The emergency call (eCall) system represents an emerging application in which emergency responders are immediately alerted after an accident through the car phone.

The responder is then able to speak with the victim through the audio systems embedded in the car. In the event of an accident, the audio systems of the car could sustain serious damage, preventing a victim from being able to hear instructions issued by emergency responders utilising the eCall system. After an accident, there are various faults which could cause the speaker system to fail.

Damage from a serious accident could result in short circuits to battery or ground, short circuits across the speaker, or disconnection of the speaker from the audio amplifier. If a failure occurs, it is important that the emergency responders be notified that the victim is unable to hear them. In this instance, load diagnostics are needed to detect potential fault conditions in order to verify the level of functionality of the system.

To read the full paper from Texas Instruments, click here.