A Reliable Method for Optimum MOSFET Selection for Any Given Application

Abstract:
Selecting the optimal switch in AC-DC and DC-DC converters is critical to achieving efficient and reliable operation. MOSFETs, as the most widely used switches, play an essential role in influencing a circuit’s switching and current delivery capabilities. Since MOSFETs often generate the most heat on a PCB, selecting an "optimum" device that balances performance and cost-effectiveness without over-specification is crucial. This paper presents a novel MOSFET selection tool that uses precise circuit-level simulations to provide recommendations based on the application’s input-output specifications. These simulations capture dynamic behaviors, including switching transients and switch-node overshoot, which are often overlooked in conventional tools. The recommendations, verified through hardware tests, support DC-DC converter topologies and BLDC motor control circuits.