IGBT Power Module Design for Suppressing Gate Voltage Spike at Digital Gate Control

This paper clarifies the effect of gate inductanceLginside IGBT modules on gate voltage spikes when a digital gate driver is employed. Three IGBT modules with differentLgwere fabricated to implement double pulse tests by conventional gate driving and digital control gate driving with three-step vectors. It was found that the tradeoff between switching loss and voltage/current overshoots can be improved by digital control, but a large gate voltage spike was generated when gate-driving vectors were changed. And the spike voltageV_g_spikewas positively correlated to theLg. Although theV_g_spikecan also be suppressed by decreasing the difference of gate driving vectors between the first and the second steps, the improvement of the tradeoff is weakened. Therefore, it is required that theLginside the IGBT modules should be reduced to suppress theV_g_spikewhile improving the tradeoff by the digital gate driver at the same time. Furthermore, by analyzing the oscillation of theV_g_spike, it indicates that there should be some other stray elements, which coupleLgand the stray capacitance inside IGBT chips, affecting theV_g_spike.