Mosfet Transistor IRF840

The Mosfet Transistor IRF840 is a high-voltage N-channel power MOSFET in a TO-220 package, rated 500 V and 8 A with an on-resistance of 0.85 Ω. Its high voltage rating suits circuits that run from rectified mains, such as switch-mode power supplies, inverters, induction heaters and electronic ballasts, as well as flyback and high-voltage pulse circuits.

Mosfet Transistor IRF840 Specifications

• Type: N-channel enhancement-mode power MOSFET
• Drain-source voltage (VDS): 500 V
• Continuous drain current (ID): 8 A at 25 °C case temperature
• On-resistance (RDS(on)): 0.85 Ω max at VGS = 10 V
• Gate-source voltage (VGS): ±20 V max
• Gate threshold voltage: 2 V to 4 V
• Power dissipation: 125 W at 25 °C case temperature
• Package: TO-220AB, pins gate, drain, source (front view, left to right); the metal tab is the drain

Mosfet Transistor IRF840 Applications

• Switch-mode power supplies working from rectified mains
• Half-bridge and full-bridge inverters
• Induction heaters and electronic ballasts
• Flyback drivers and high-voltage pulse circuits
• Replacement part when repairing power supplies and inverters

What's in the Box

• 1 × IRF840 N-channel MOSFET

Tip: Drive the gate with about 10 V for full turn-on; a 5 V microcontroller pin is not enough, so use a gate driver IC such as the IR2110 for bridge circuits. Circuits at mains voltage are dangerous: insulate the tab from the heatsink where needed and work on the board only with the power disconnected.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.