Edge shaping to reduce the electromagnetic emissions

In this paper the reduction of the electromagnetic emission of automotive power ICs by shaping the edges of the switching signal is described. This technique is explained in detail and it is shown how an edge shaping concept was implemented into a high side switch. Using the voltage method defined in CISPR25 the conducted electromagnetic emission of this high side switch was measured. For this purpose an EMC test board was designed and the electromagnetic emission with and without edge shaping are compared.