What happens when the gate voltage VGS exceeds the specified range?
The max values in the data sheet (+20 V/-10 V) take into account transient spikes at the gate signal of 5 V max (exceeding the designed gate drive output), which appear no longer than 1% of the total lifetime
– Theoretically, the VGSon could also selected to be a higher value, e.g. 18V, however this will reduce the margin for gate voltage overshoot, which could be challenging for gate drive design and layout.
– Since negative VGSoff for turn-off can have additional impact in the case of CoolSiC™ MOSFETs, Infineon recommends in general to keep the turn-off bias as high as possible, ideally VGSoff = 0 V"