Overcoming switching limits in silicon power MOSFETs with silicon‐based solutions

Abstract

This work presents a review of new concepts and trends to push silicon power MOSFETs beyond their switching boundaries. The multiple issues encountered when increasing switching power loss and slew rate are thoroughly explained. Afterwards, a large variety of solutions are proposed in silicon technologies, all of them being experimentally proven and elucidated by physics-based simulations. Among these solutions, co-integrated snubbers, induced avalanche operation, local charge balance, tapered trenches, and cascoded configuration are suggested for low-and high-voltage power MOSFETs.

Non-Linear Capacitance of Si SJ MOSFETs in Resonant Zero Voltage Switching Applications

“…After both C oss and V supply have reached the same voltage, V DC , the scenario becomes equal to the one analyzed in the previous section for single device topologies, where the initial energy required in the inductor is equal to E ind,1 (8). Therefore, the initial energy required at the start of the transition would be E ind,1 minus the additional E ind that has already been stored in the inductor during the natural balance of the capacitor voltage (17)(18)(19). (19) Because of this, the higher the initial difference between the voltages the lower the required initial stored energy in the resonant inductor.…”

“…Therefore, the initial energy required at the start of the transition would be E ind,1 minus the additional E ind that has already been stored in the inductor during the natural balance of the capacitor voltage (17)(18)(19). (19) Because of this, the higher the initial difference between the voltages the lower the required initial stored energy in the resonant inductor. The turning point is the one where the initial required energy in the inductor E ind,2 equals zero, which occurs when E ind is greater than or equal to E ind,1 (20).…”

“…Another key design paradigm in modern high-efficiency SMPS is the reduction of switching losses by the improvement of the characteristics of the switching device itself. Silicon (Si) based power switching devices have continuously improved their Figure Of Merit (FOM) becoming closer and closer to the theoretical limit of the material itself [18], [19]. Frequently, the improvement of the FOM implies certain side effects on the device characteristics, e.g.…”

High Step-Down Isolated PWM DC–DC Converter Based on Combining a Forward Converter With the Series-Capacitor Structure

“…At this point, a qualitative analysis of switch losses can be addressed. The target of this analysis is to identify the differences between both converters in terms of switch losses rather than accurately estimating them (which typically requires non-analytical approaches, such as TCAD simulations [42], [43]). It is important to note that synchronous rectification is considered in this section and, moreover, inductor current ripples are neglected.…”