Power MOSFET Technologies and Design Considerations for Automotive Electronic Systems

For over thirty years, the silicon power MOSFET’s role has expanded from a few key components in electronic engine control to a key component in nearly every automotive electronics system. New and emerging automotive applications such as 48 V micro hybrids and autonomous vehicle operation require improved power MOSFET performance. This paper reviews mature and state of the art power MOSFET technologies, from planar to shield gate trench, with emphasis on applicability to automotive electronic systems. The automotive application environment presents unique challenges for electronic systems and associated components such as potential for direct short to high capacity battery, high voltage battery transients, high ambient temperature, electromagnetic interference (EMI) limitations, and large delta temperature power cycling. Moreover, high reliability performance of semiconductor components is mandatory; sub 1 ppm overall failure rate is now a fundamental requirement. Autonomous vehicle operation and associated higher safety levels drive even higher reliability requirements for electronic systems. This paper examines the different power MOSFET operation modes with emphasis on avalanche operation, saturation operation, and switching performance in relation to automotive application requirements. In addition, thermal management of power MOSFET, and relation to device packaging is discussed. Overall, the paper intent is to provide automotive electronic system designers a better understanding of power MOSFET device technologies and understanding of performance tradeoffs for different application requirements.