Inter-chip Oscillation of paralleled SiC MOSFETs

Inhalt:
This paper analyzes the problem of instability between paralleled silicon carbide (SiC) MOSFETs. In certain parasitic conditions, self-excited oscillation of paralleled SiC MOSFETs occurs and forms a positive, oscillatory feedback loop. This kind of oscillation is called inter-chip oscillation and can lead to loss of control, resulting in device breakdown, decreased lifetime, or significantly higher EMI. This paper shows typical inter-chip oscillation characteristics, an extended analytical stability model is presented, and additional influencing factors beyond system damping are derived.