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IRF840 Power MOSFET: Application, Pinout, Testing Circuit, Datasheet [Video]

  • Contents

The IRF840 is an n-channel power MOSFET. It is a fast switching and high voltage device that is available with low on-state resistance.

Catalog

Introduction to IRF840

IRF840  CAD Model

IRF840 Pinout

Pin Configuration

IRF840 Features

Specifications

Replacement and Equivalent

IRF840 Package

Testing Circuit

IRF840 Applications

2D Model of the Component

Where We Can Use it & How to Use?

How to Safely Long Run in a Circuit?

IRF840 Datasheet

FAQ

 

Introduction to IRF840

The IRF840 is an n-channel power MOSFET that supports loads up to 8A and 500V. It is a fast switching and high voltage device that requires 10V across the gate terminal to initiate the conduction process.

This IRF840 MOSFET is a three-terminal device made of gate (G) drain (D) and source (S) terminals. The external circuits are connected with these MOSFETs through these terminals.

This is an N-channel MOSFET, here the conduction process is exercised by the flow of electrons in contrast to the P-channel MOSFET where the conduction process is carried out by the flow of holes.

It is important to note that conduction is a process that is carried out inside MOSFET by the movements of both electrons and holes but electrons are major carriers in the n-channel MOSFET devices while holes are major carriers in the p-channel MOSFET devices.

How to make stereo power amplifier using mosfet IRF840

 

The MOSFET stands for Metal Oxide Silicon Field Effect Transistor. It is also known as IGFET Insulated Gate Field Effect Transistor. It is made by the controlled oxidation of a silicon semiconductor material.

MOSFETs and BJTs (bipolar junction transistors) are considered as different semiconductors as BJT is a current-controlled device while the MOSFET is a voltage-controlled device.

The voltage applied at the gate terminal usually is directly related to the current between the source and drain terminals. The gate terminal voltage controls the current at the drain and source terminals. Simply put, the gate terminal acts like a control valve that controls the current between two terminals.

 
 

 IRF840  CAD Model

 

 IRF840  CAD Model

 IRF840  CAD Model
 
 
 

IRF840 Pinout

 

IRF840 Pinout

IRF840 Pinout
 

Pin Configuration

 
Pin Number PinName Description
1 Source Current flows out through Source (maximum 8A)
2 Gate Controls the biasing of the MOSFET (Threshold voltage 10V)
3 Drain Current flows in through Drain
 

IRF840 Features

 
  • Type: N-Channel fast switching Power MOSFET
  • Rise time and the fall time is 23nS and 20nS respectively
  • Gate threshold voltage (VGS-th) = 10V (limit = ±20V)
  • Continuous Drain Current (ID) = 8A
  • Drain Source Resistance (RDS) = 0.85 Ohms
  • Available package = TO-220
  • Drain to Source Breakdown Voltage = 500V

 

 

Specifications

Product Attribute Attribute Value
Manufacturer: STMicroelectronics
Product Category: MOSFET
RoHS: Details
Technology: Si
Mounting Style: Through Hole
Package / Case: TO-220-3
Transistor Polarity: N-Channel
Number of Channels: 1 Channel
Vds - Drain-Source Breakdown Voltage: 500 V
Id - Continuous Drain Current: 8 A
Rds On - Drain-Source Resistance: 850 mOhms
Vgs - Gate-Source Voltage: - 20 V, + 20 V
Minimum Operating Temperature: - 65 C
Maximum Operating Temperature: + 150 C
Pd - Power Dissipation: 125 W
Channel Mode: Enhancement
Packaging: Tube
Configuration: Single
Height: 9.15 mm
Length: 10.4 mm
Series: IRF840
Transistor Type: 1 N-Channel
Width: 4.6 mm
Brand: STMicroelectronics
Fall Time: 9 ns
Product Type: MOSFET
Rise Time: 21 ns
Factory Pack Quantity: 50
Subcategory: MOSFETs
Typical Turn-On Delay Time: 10 ns
Unit Weight: 0.068784 oz

 

 

Replacement and Equivalent

YTA840, IRF841, IRF842, IRF843, IRFI840G, IRFS840, IRFS841, STP8NA50, 2SK554, 2SK1158, 2SK1566, 2SK1567, 2SK1805, 2SK2116, 2SK2117, 2SK2118, 2SK2175, IRF744.

 

IRF840 Package

 

IRF840 Packing

IRF840 Packing

 

Testing Circuit

 

Unclamped-Inductive-Load-Test-Ciruit

Unclamped Inductive Load Test Ciruit

 

 

Swithing-Times-Test-Circuit-For-Resistive-Load

 Swithing Times Test Circuit For Resistive Load

 

 

Gate-Testing-Circuit

 Gate Testing Circuit

IRF840 Applications

  • The IRF840 is used in the following applications.
  • Used in Inverter Circuits and DC-DC Converters.
  • Incorporated in High-Speed switching applications.
  • Used for switching high power devices.
  • Employed in Control speed of motors and LED dimmers or flashers.

 

2D Model of the Component

If you are designing a PCB or Perf board with this component then the following picture from the IRF840 Datasheet will be useful to know its package type and dimensions.

 

2D-model-of the-component

2D model of the component

 

 

Where We Can Use it & How to Use?

IRF640 can be used in circuit where you want to drive a high voltage load of upto 500V with upto 8A load current. It can also be used in circuits where high speed switching is crucial. Additionally you can use it directly at the output of ICs, microcontrollers and other electronic platforms like Arduino and Raspberry Pi to drive loads.

Other than that it can also be used to build high power audio amplifiers.

 

 

How to Safely Long Run in a Circuit?

To get long term performance it is always better to use a component on its full extent or on its maximum limits. Therefore we suggest to always use a component to its 80% capability or 20% below from its max ratings. The max load voltage IRF840 can handle is 500V therefore do not drive load of more than 400V. The max drain current is 8A therefore do not drive load of more than 6.4A and always operate the transistor in temperature above -55 degree centigrade and below +150 degree centigrade.

 

IRF840 Datasheet

IRF840 Datasheet

 

 

 

FAQ

What is IRF840?

The IRF840 is an N-Channel Power MOSFET which can switch loads upto 500V. The Mosfet could switch loads that consume upto 8A, it can turned on by providing a gate threshold voltage of 10V across the Gate and Source pin. ... Hence this mosfet cannot be used in applications where high switching efficiency is required.

 

How many drain S is are there in a IRF840?

It is a fast switching and high voltage device that requires 10V across the gate terminal to initiate the conduction process. This IRF840 MOSFET is a three-terminal device made of gate (G) drain (D) and source (S) terminals.

 

How do you know if a MOSFET is good or bad?

A good MOSFET should have a reading of 0.4V to 0.9V (depends on the MOSFET type). If the reading is zero, the MOSFET is defective and when the reading is “open” or no reading, the MOSFET is also defective. When you reverse the DMM probe connections, the reading should be “open” or no reading for a good MOSFET.

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