How to Select the Right Power MOSFET

How to Select the Right Power MOSFET

According to figures compiled by the Information Network, power MOSFETs will represent a $6.3 billion business by 2017. The attributes possessed by these devices makes them favourable over other power ICs (such as BJTs) when it comes to switch functionality. As well as supporting heightened switching speeds, they have less complex supporting drive circuitry, superior frequency response, elevated input impedance, greater current gain and better temperature stability. There is a broad array of products on the market to choose from, available through a multitude of manufacturers, so being fully aware of the different traits that define MOSFETs is certain to help during the specification process.

First and foremost, the MOSFET’s on-state resistance should be taken into consideration. Inherent to such devices, it is the principal source of static power loss. There is cumulative pressure to make domestic appliances and vehicles more energy efficient, along with consumers expecting more extensive battery lives for portable electronics goods. The significance of on-state resistance thus continues to increase. It is consequently crucial that engineers have a firm grasp of how this will affect the system into which the MOSFET will be incorporated. Other key electrical parameters include the threshold voltage, current rating, gate charge and breakdown voltage. How these parameters manifest themselves relates directly to the MOSFET topology that has been utilized and the semiconductor process technology on which the device is based. Understanding their respective merits is therefore important. With MOSFETs suffering numerous different power losses (resulting in heat being generated), these components also need to be accompanied by appropriate levels of thermal management.

To learn more about what to look for when selecting power MOSFETs, download Toshiba’s latest white paper.

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