EMC Europe

Failures in digital devices can be caused by ESD-pulses coupled directly or indirectly to input pins. Weak pulses will not destroy a device but can be interpreted as logical signals (ESD soft failure). In this paper, a modelling and characterization methodology for a microcontroller input is proposed. With this model the ESD soft failure behaviour can be simulated. First a measurement setup for characterization of input behaviour was developed and applied to a commonly used microcontroller. For the digital input an RC model approximation is used and related parameters are extracted. SPICE simulations have been performed and results have been compared with the measurements. It could be shown that the RC model can predict quite well the ESD soft failure behaviour.