Load Dependency Assessment of the EMC Immunity for Integrated Low Side Drivers

In automotive electronics, IC outputs are connected to a wide range of impedances generated by external circuitry or wiring harness. This load alteration, which is not fully covered by the established standard direct power injection (DPI), impacts the EMC immunity and should therefore be taken into account during susceptibility analyses. This paper introduces two S-parameter-based approaches which enable a simplified but sufficiently accurate assessment of the load dependency of the immunity. The proposed methods have been tested experimentally for a low-side driver and their validity is analyzed by comparison with measurement and large-signal simulation results.