Evaluation of Lateral Power MOSFETs in a Synchronous Buck Converter Using a Mixed-Mode Device and Circuit Simulation

Abstract

This paper presents an evaluation of laterally double-diffused MOS transistors in synchronous dc-dc buck converters using a physical-based mixed device and circuit simulation. It is observed that impact ionization of the low-side transistor can be very high after the dead-time drain overshoot voltage point. In addition, heavy ion irradiation degrades power MOSFET performance and may lead to a potential circuit malfunction due to a significant increase in transient current if heavy ions strike the dc-dc buck converter at a critical time during switching.