An Adjacent Miller Clamp Circuit for Crosstalk Suppression in SiC MOSFETs

Crosstalk can be a serious issue for Silicon Carbide MOSFETs owing to their features of high switching speed, low threshold voltage and narrow permissible gate-source voltage range. Therefore, extra methods should be adopted to use SiC MOSFETs at their full potential. In this paper, the mechanism of crosstalk is analyzed under the influence of parasitic parameters, considering both common source connection and Kelvin source connection in drive circuits. Then, based on the structures of half-wave synchronous rectification, several novel auxiliary circuits are proposed, which are simple, compact, lossless and can be easily placed near SiC MOSFETs. Furthermore, the circuits can expand the operating voltage range since they have little impact on the positive inputs but can protect the chips from large negative inputs. Finally, verification experiments were conducted, in which the positive spikes were reduced by 66% from 5.0V to 1.7V while the negative spikes were alleviated by 68% from -6.0V to -1.9V. The results could verify the effectiveness and feasibility of the proposed circuits.