In addition to basic switching functionality, smart power switches mainly provide diagnostic and protection functions, e.g. for short circuits to the load, which makes it all the more surprising that short circuit protected smart switches have been used for years in automotive applications without there being a precise definition of a short circuit.
This article describes what Infineon has done to fill this gap. It was first necessary to define the kind of short circuits likely to occur in automotive applications and to specify the use and operating points of the smart switches. The next logical step was the standardization of the test circuit and application conditions in the AEC (Automotive Electronics Council) to allow an industry-wide comparison of the test results.
On this basis, extensive characterization testing was carried out on existing and new smart power switches, and supplementary specifications were written for repetitive short circuits, specifically in terms of the number of cycles and operating life. Furthermore, the user receives additional practical recommendations for creating a lifetime-extending software strategy in order to build electronic systems that are more robust with respect to short circuits.