MOSFET stands for metal oxide semiconductor field effect transistor. In the PC world, you’ll find these electrical components on a desktop (opens in new tab) or laptop motherboard (opens in new tab), as well as a desktop power supply unit (PSU) (opens in new tab).
On a PC, MOSFETs help make up the VRM (opens in new tab) (voltage regulator module), which controls how much voltage other components on the motherboard, like the CPU (opens in new tab) or graphics card (opens in new tab), receive.
PC components like CPUs and graphics cards have strict operating voltages, so a motherboard’s VRM helps make sure this isn’t exceeded. MOSFETs are important to VRM functionality and have an impact on the amount of heat being generated by a VRM while it’s doing its job. MOSFETs can get quite toasty if you’re using a powerful graphics card (opens in new tab), and a motherboard’s heatsink (opens in new tab) helps cool the MOSFETs and, thus, the VRM. In addition to keeping the overall system safe, keeping MOSFETs cool is also important for any type of overclocking (opens in new tab).
How Do They Work?
MOSFETs are like switches that go on and off based on a signal from an integrated circuit (IC) called the PWM chip / controller. MOSFETs switch on and off quickly, allowing high current to flow through in short bursts. This, along with other parts of the VRM, controls voltage sent to other PC components on the motherboard.
To keep motherboard MOSFETs cool during extreme overclocking, PC enthusiasts often use waterblocks. Vendor EK also makes Monoblocks, which is a shared CPU and MOSFET waterblock.
MOSFETs and Power Supplies
MOSFETs perform a similar function on PC power supplies.They’re used in convertors and regulator circuits for switching purposes in switched-mode power supplies (SMPS).
In an SMPS, energy is pulled from an AC socket before its broken down into small packets with the MOSFETs acting as switchers. Those packets are then carried via capacitors (opens in new tab), inductors and more electric components capable of storing energy. Ultimately, the packets merge into one for a single, and steady, output.
This article is part of the Tom's Hardware Glossary (opens in new tab).
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