Copyright: RWTH IAS

For the control of power switches such as MOSFETs or IGBTs, for example in the field of automotive, gate drivers are necessary. The steep switching edges cause unwanted electromagnetic emissions (EMI) and ringing on the switched nodes. In order to reduce these problems and to increase the switching efficiency, IAS is researching on intelligent gate drivers. These reduce the described problems by techniques like gateshaping. The monolithic integration of gate drivers offers a much better time resolution than is possible with discrete topologies. This also enables transmission to the latest technologies of power switches - for example, SiC MOSFETs.

When applying gateshaping, the charging and discharging process of the gate is controlled. As a result, the switching processes of the circuit breakers can be selectively decelerated at a time, which is found to be particularly suitable, within the switching edge in order to come as close as possible to an ideally desired switching process. Thus, for example a change in the charging current during the Miller plateau leads to improvements in the EMI or to a faster and thus more energy-efficient switching operation with the same EMI. In addition, it is possible to provide mechanisms for protecting the power switch, for example from a short circuit, without significantly increasing the overall dimensions or the number of components.