Distributed Kelvin-Source Resistance to Reduce Dynamic Power/Current Imbalance in Paralleled Semiconductor Power Switches

Switching power devices, especially SiC MOSFETs, have wide parameter variations due to fabrication process. When putting several MOSFETs in parallel, there will be current/power unbalance during switching transient. Several publications have mentioned about using different control techniques to actively reduce the unbalance. However, these controls are usually quite complicated and not so practical in reality. Complicated current sensor and gate driver are required for every switch. This ID presents an alternative method to passively reduce the imbalance by carefully designing the kelvin source resistance. The dynamic current/power unbalance can be greatly reduced without sacrificing other switching performances, such as switching loss and voltage stress. This invention is effective, simple and low-cost in real manufacturing process.

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For Information, Contact:
Li Chen
Licensing Associate
Virginia Tech Intellectual Properties, Inc.
(540) 443-9217
Yincan Mao
Zichen Miao
Khai Ngo
Chi Ming Wang