The Ultimate Guide to Buying MOSFETs

Your Guide to buying the best MOSFETs

Overview

MOSFETs, or metal-oxide-semiconductor field-effect transistors, are an essential component in many electronic circuits. They are used to control the flow of electricity in an electronic circuit and can be used to amplify or switch electric signals. This buying guide will provide an overview of MOSFETs and provide guidance on how to select the right type for a given application. We will discuss the properties and parameters of MOSFETs, as well as the various types available on the market and how to choose the best one for the job. Finally, we will discuss the technical aspects of MOSFETs to ensure that the correct device can be chosen for the project.

Key features

  • Purpose - What do you plan to use the MOSFETs for? Is it a general purpose application or specific use?
  • Package Types - What package types are available? (DIP, SMD, etc.)
  • Voltage Rating - What is the maximum voltage rating for the MOSFETs?
  • Current Rating - What is the maximum current rating for the MOSFETs?
  • Drain-Source On-Resistance - What is the drain-source on-resistance of the MOSFETs?
  • Gate-Source Voltage - What is the gate-source voltage of the MOSFETs?
  • Power Dissipation - How much power will the MOSFETs be able to dissipate?
  • Input Capacitance - What is the input capacitance of the MOSFETs?
  • Gate Threshold Voltage - What is the gate threshold voltage of the MOSFETs?
  • Temperature Range - What is the operating temperature range of the MOSFETs?
  • Price - What is the cost of the MOSFETs?

See the most popular MOSFETs on Amazon

Important considerations

Pros

  • High Input Impedance: MOSFETs are voltage-driven, as opposed to current-driven, and so have a very high input impedance which can be up to 1000 times higher than bipolar transistors.
  • Low Input Current Required: MOSFETs require very low input current to be switched on, so they can be used in battery-operated devices.
  • Fast Switching: MOSFETs can switch high frequencies more quickly than bipolar transistors, making them ideal for use in high-speed applications.
  • Low On-State Resistance: MOSFETs have a low on-state resistance, making them ideal for applications where low power dissipation is desirable.
  • Low Cost: MOSFETs are cheaper than other types of transistors, making them an attractive option for cost-sensitive applications.
  • Small Size: MOSFETs are available in small packages, making them suitable for use in applications where space is at a premium.
  • High Power Ratings: MOSFETs can be used in applications requiring high power ratings due to their high current capacity.

Cons

  • High Cost - MOSFETs are typically more expensive than other transistors and may not fit into all budget constraints.
  • Vulnerability to ESD - MOSFETs are particularly vulnerable to electrostatic discharge, making them unreliable for some applications.
  • Heat Generation - MOSFETs can generate a lot of heat, necessitating special cooling mechanisms or heatsinks. This means more cost and complexity.
  • Hard to Troubleshoot - MOSFETs can be difficult to diagnose and troubleshoot, especially for novice users.

Best alternatives

    JFETs - Junction Field Effect Transistors, which are similar to MOSFETs but with a different construction. IGBTs - Insulated Gate Bipolar Transistors, which are more efficient and have lower leakage than MOSFETs. Power MOSFETs - A type of MOSFET designed for higher power applications. BJTs - Bipolar Junction Transistors, which are the most common type of transistors, but not as efficient as MOSFETs. UJTs - Unijunction Transistors, which are used for controlling current in circuits.

Related tools, supplies, and accessories

  • Soldering Iron - A soldering iron is necessary to connect the MOSFET to the circuit.
  • Heat Sink - Heat sinks are used to dissipate the heat generated by the MOSFET.
  • Multimeter - A multimeter is used to measure voltage, current, and resistance.
  • Power Supply - A power supply is required to power the circuit.
  • Prototyping Board - A prototyping board is used to build the circuit.
  • Wire Cutters - Wire cutters are used to cut and strip the wires.
  • Digital Oscilloscope - A digital oscilloscope is used to measure and analyze the waveforms.

Common questions

  1. What is a MOSFET? A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a type of transistor that is used as a switch or amplifier in electronic circuits.
  2. What are the different types of MOSFETs? The two main types of MOSFETs are N-type and P-type. N-type MOSFETs are used for switching and P-type MOSFETs are used for amplifying.
  3. What should I consider when buying a MOSFET? When buying a MOSFET, you should consider the type of application you are using it for, the power requirements, the breakdown voltage, the current handling capacity, the gate capacitance, and the temperature range.
  4. What is the breakdown voltage of a MOSFET? The breakdown voltage of a MOSFET is the voltage at which the MOSFET begins to conduct current.
  5. What is the current handling capacity of a MOSFET? The current handling capacity of a MOSFET is the maximum current it can handle without becoming damaged.
  6. What is the gate capacitance of a MOSFET? The gate capacitance of a MOSFET is the amount of capacitance between the gate and the source.
  7. What is the temperature range of a MOSFET? The temperature range of a MOSFET is the range of temperatures in which the MOSFET can operate without becoming damaged.

Trivia

In the early days of MOSFETs, they were so delicate that when engineers used to test them, they needed to hold them in tweezers. The fragility of the transistors was so great that the heat from the engineer's hands was enough to blow them up. This led to a rule that they could only be tested while wearing gloves. However, this rule has since been relaxed as the technology has become more reliable and robust. Source: https://www.allaboutcircuits.com/news/the-evolution-of-mosfets-from-discrete-components-to-integrated-devices/.

Disclaimer: This buying guide was not created by humans, and it is possible that some of it's content is inaccurate or incomplete. We do not guarantee or take any liability for the accuracy of this buying guide. Additionally, the images on this page were generated by AI and may not accurately represent the product that is being discussed. We have tried to convey useful information, but it is our subjective opinion and should not be taken as complete or factual.