An Improved SPICE Model of SiC BJT Incorporating Surface Recombination Effect

作者：Wang, Jun; Liang, Shiwei^*; Deng, Linfeng^*; Yin, Xin; Shen, Z. John

来源：IEEE Transactions on Power Electronics, 2019, 34(7): 6794-6802.

DOI：10.1109/TPEL.2018.2871594

• Bipolar junction transistor (BJT)
• proportional base driver
• SPICE model
• surface recombination effect
• 4H-SiC

The SiC bipolar junction transistor (BJT) offers an attractive alternative to the more popular SiC MOSFET. It is important to develop an accurate SPICE model for the SiC BJT to enable its use in power electronic applications. The current gain of an SiC BJT may degrade considerably at high current levels and/or at high temperatures largely due to the surface recombination effect. In this paper, an improved SPICE behavioral model that accurately accounts for the current gain depending on the collector current and the junction temperature is proposed for the SiC BJT. In this paper, the conventional Gummel-Poon model is extended to include this important physical effect by adding a diode between the external base and emitter terminals of the BJT. A two-step model parameter extraction method is developed. First, the basic Gummel-Poon model parameters are extracted from low-current measurement data, and then, the new surface recombination model parameters are extracted by observing the difference between the measured high-level base current and the standard Gummel-Poon model prediction. The simulated static and switching characteristics of the new SiC BJT model match the measured data very well. Finally, the new SPICE model is used in the performance assessment of a proportional base driver technique embedded in a 3.6-kW boast converter, demonstrating its validity in helping with the optimum design of power electronic applications based on SiC BITs.

• 出版日期2019-7
• 单位湖南大学