Anatomy of a Power MOSFET Abstract

Since their introduction in the 1970s, silicon power MOSFETs have become the dominant switching element used for power conversion at mains voltages and lower. The relentless drive towards lower conversion losses, smaller size, and lower cost has resulted in this ‘simple’ switch becoming a highly optimised and complex component.  The high level of innovation in this area has led to the evolution of many competing device structures, each with its own advantages and disadvantages depending on the application in which it is used. Common figures of merit, such as QGD●RDS(ON) and QG●RDS(ON), can no longer be used as a realistic estimation of device performance as  packaging, reverse recovery, output capacitance, EMI suppression, ruggedness, reliability etc. can also be critical. The design of the MOSFET also has a major impact; poor design can turn a great technology into a mediocre product. The target application ultimately determines what is considered a high performance product and this can vary wildly depending on the design goals (e.g. size, cost, efficiency, reliability, and time to market). For example, the requirements for a voltage regulator are not necessarily the same as for hot swap.

This on-line seminar will dissect a modern low voltage Power MOSFET, discussing how the many factors involved in making a high performing device interact & conflict with each other, and how they are fundamentally limited.

Dr. Phil Rutter
PowerMos Technology Architect