Zero-current soft-switching performance of 1200-V PT clustered insulated gate bipolar transistor

Zero-current soft-switching performance of a 1200-V, 20-A punch-through (PT) clustered insulated gate bipolar transistor (CIGBT) is evaluated in this paper. Turn-on over-voltage transients have been witnessed in 2-D numerical simulations and experimental results. These have been shown to be influenced by circuit parameters and internal device structure. Conductivity modulation lag within the device is found to be dependant upon dI/dt; however, this alone does not explain the significant over-voltages at turn-on. The device structure is found to influence the magnitude of such voltage peaks. By optimization of the structure, over-voltages can be minimized, resulting in a significant improvement in losses compared to an IGBT. The current bump associated with zero-current turn-off has been analyzed under various dV/dt values and is influenced by circuit capacitance, switching timings, and carrier lifetime. Internal dynamics of the CIGBT have been analyzed to give an insight into the performance under zero-current switching (ZCS). ZCS tests at 600 V, 20 A have shown that the CIGBT performs well with respect to a commercial IGBT of the same rating. Dynamic saturation voltage of the CIGBT has been shown to be 15% lower at room temperatures to that of an equivalent IGBT.