Investigate of Gate Driver Loop Impedance on Switching Transients of Both Power Device Side and Gate Driver Side

This paper studies the impacts of gate driver loop impedance on the switching transients for both power transistor and gate driver by adjusting gate resistor $(R_{g})$, gate-source capacitor $(C_{gs})$ and ferrite bead $(Z_{bead})$. The effects of $R_{g},C_{gs}$ and Z
bead
on the switching speed, switching losses, voltage/current overshoot, and electromagnetic interference (EMI) of power device switching transients are discussed respectively. In addition, the crosstalk effects of $R_{g}, C_{gs}$ and Z
bead
on the gate-source voltage are also investigated. Based upon the experimental results, the increase of $R_{g}, C_{gs}$ and Z
bead
will lead to decrease of the switching speed of the power device, which will bring the benefits of reduced overshoot and EMI at the expense of switching losses. Furthermore, the increase $\mathrm{o}\mathrm{f}R_{g}$ and Z
bead
will suppress the crosstalk at the gate driver side caused by the common source inductor $(L_{scom})$. However, the crosstalk caused by the miller capacitor $(C_{gd})$ will be accelerated. Increasing C
gs
can suppress the crosstalk caused by both L
scom
and C
gd
. By comparing the influence of the three methods of changing $R_{g}, C_{gs}$ and Z
bead
, it is found that increasing gate-source capacitor is the most effective method to suppress EMI in the gate drive side compared with the other two methods.