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IRF840 N-Channel Power Mosfet

[Click the image to enlarge it]

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.

 

Pin Configuration

Pin Number

Pin Name

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

 

Features

·         N-Channel Power MOSFET

·         Continuous Drain Current (ID): 8A

·         Gate threshold voltage (VGS-th) is 10V (limit = ±20V)

·         Drain to Source Breakdown Voltage: 500V

·         Drain Source Resistance (RDS) is 0.85 Ohms

·         Rise time and fall time is 23nS and 20nS

·         Available in To-220 package

 

Note: Complete technical details can be found at the IRF840 datasheet linked at the bottom of the page

 

Alternatives for IRF840

8N50, FTK480, KF12N50

 

Other N-channel MOSFETS

IRF740, BSS138, IRF520, 2N7002, BS170, BSS123, IRF3205, IRF1010E

 

About 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. Since the mosfet is for switching high current high voltage loads it has a relatively high gate voltage, hence cannot be used directly with a I/O pin of a CPU. If you prefer a mosfet with low gate voltage then try IRF540N or 2N7002 etc.

One considerable disadvantage of the IRF840 Mosfet is its high on-resistance (RDS) value which is about 0.85 ohms. Hence this mosfet cannot be used in applications where high switching efficiency is required. The Mosfet requires a driver circuit to provide 10V to the gate pin of this Mosfet the simplest driver circuit can be build using a transistor. It is relatively cheap and has very low thermal resistance, added to this the mosfet also has good switching speeds and hence can be used in DC-DC converter circuits.

 

Applications

  • Switching high power devices

  • Inverter Circuits

  • DC-DC Converters

  • Control speed of motors

  • LED dimmers or flashers

  • High Speed switching applications

 

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.

 IRF840 N-Channel Power Mosfet 2-D Model

 

Component Datasheet

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