Analysis and modeling of DMOS FBSOA limited by n-p-n leakage diffusion current

• Published in: Proceedings. ISPSD '05. The 17th International Symposium on Power Semiconductor Devices and ICs, 2005 pp. 331 - 334
• Main Authors: Denison, M., Pfost, M., Stecher, M., Silber, D.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2005
• Subjects: Alternators; Automotive applications; Batteries; Charge carrier processes; Manifolds; MOSFETs; Temperature distribution; Threshold voltage; Vehicle dynamics; Voltage control
• DOI: 10.1109/ISPSD.2005.1488018
• ISBN: 0780388909; 9780780388901
• ISSN: 1063-6854

Failure of DMOS self-heated in saturation below the avalanche threshold is usually related to an activation of the parasitic n-p-n transistor. In this work we show that the exponential increase of the leakage diffusion current of the n-p-n is sufficient to cause thermal runaway, even for a slightly reverse body-source bias caused by the internal ballasting source resistance. Adding this current contribution to a basic DMOS compact model allows simulating the thermal limit of large DMOS transistors considered as distributed electrothermal networks. To our knowledge it is the first report of a quantitative DMOS FBSOA model accounting for the instabilities driven by the temperature dependences of both MOS and n-p-n components