*Article* **Electrothermal Model of SiC Power BJT**

### **Joanna Patrzyk \*, Damian Bisewski and Janusz Zar ˛ebski**

Department of Marine Electronics, Gdynia Maritime University, 81-225 Gdynia, Poland; d.bisewski@we.umg.edu.pl (D.B.); j.zarebski@we.umg.edu.pl (J.Z.)

**\*** Correspondence: j.patrzyk@we.umg.edu.pl; Tel.: +48-58-5586-575

Received: 28 March 2020; Accepted: 17 May 2020; Published: 21 May 2020

**Abstract:** This paper refers to the issue of modelling characteristics of SiC power bipolar junction transistor (BJT), including the self-heating phenomenon. The electrothermal model of the tested device is demonstrated and experimentally verified. The electrical model is based on the isothermal Gummel–Poon model, but several modifications were made including the improved current gain factor (β) model and the modified model of the quasi-saturation region. The accuracy of the presented model was assessed by comparison of measurement and simulation results of selected characteristics of the BT1206-AC SiC BJT manufactured by TranSiC. In this paper, a single device characterization has only been performed. The demonstrated results of research show the evident temperature impact on the transistor d.c. characteristics. A good compliance between the measured and calculated characteristics of the considered transistor is observed even in quasi-saturation mode.

**Keywords:** BJT; modelling; self-heating; silicon carbide; SPICE
