IRF840 N-Channel Power Mosfet

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

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.