Analytical Model and Safe-Operation-Area Analysis of Bridge-Leg Crosstalk of GaN E-HEMT Considering Correlation Effect of Multi-Parameters

Wide band-gap (WBG) field-effect power devices such as Gallium nitride high electron mobility transistors (GaN E-HEMTs) are being widely used for a better system-level performance as a result of superior figure-of-merits in power-conversion application. But they could also suffer from more severe bridge-leg crosstalk issue in fast-switching operation due to their special device features. To suppress the bridge-leg crosstalk, an explicit model and theoretical analysis which could guide collaborative optimization of multi-parameter is required. However, the superposition of two noise excitations ( di/dt and dv/dt ) and high order circuit structure bring difficulties to modeling and analysis. By the physical behaviors of different switching stages, the generation of crosstalk voltage is analyzed. This paper proposes an analytical model of crosstalk voltage, with the explicit representation of parasitic parameters. Based on the model, an exhaustive investigation into the correlation of parameters on the crosstalk voltage is conducted. Further, a scheme for multi-parameters collaborative optimization is presented, the safe operational area (SOA) for crosstalk suppression has been determined. The superiority of the proposed model and the effectiveness of the optimization scheme are verified with simulations and experiments on a double pulse test platform. The model and analysis method can guide the selection of GaN devices and the design of parameters, which is convenient for the pre-test of PCB before power on.