A Novel Method for Testing the Electromagnetic Immunity of the Short Circuit Protection Function of Smart Power Switches

This paper investigates the robustness of the shortcircuit protection function of automotive smart power switches. These devices are being used more and more in vehicles and are performing more and more safety-related functions. Since a modern car is full of electronics, compliance with the relevant electromagnetic compatibility (EMC) standards is a prerequisite for safe operation. However, the EMC standards do not cover safety functions such as overtemperature or short-circuit protection. This can lead to a potential safety risk in the end product. Therefore, we present a system that combines the short circuit test and the direct power injection (DPI) immunity test to investigate the electromagnetic immunity of the short circuit protection function. We show a new test method, apply it on two representative devices from different manufacturers, and discuss the results. The short-circuit protection function of the tested devices seems to be robust against electromagnetic disturbances, while some weaknesses in the diagnostic output were found, which may lead to a misinterpretation of the failure state of the device under test (DUT).