IRFN340 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRFN340
The IRFN340 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 400 V, a continuous drain current (ID) of 10 A and an on-resistance (RDS(on)) of 0.55 Ω. It can dissipate up to 125 W and is rated to a junction temperature of 150 °C. It is supplied in the SMD1 package.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 400 V
- Max continuous drain current (ID): 10 A
- On-resistance (RDS(on)): 0.55 Ω
- Power dissipation (PD): 125 W
- Max junction temperature (TJ): 150 °C
- Package: SMD1
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 400 V drain–source rating the IRFN340 sits in the medium-high-voltage class of switching MOSFETs, typically found in telecom and industrial DC rails, boost and flyback converters, LED and backlight drivers and power-factor-correction stages. Common where the bus sits well above 100 V but below rectified mains.
Gate drive and switching notes
Keep gate–source voltage within the ±20 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.
Switching behaviour is characterised by a rise time of 92 ns and an output capacitance (Coss) of 3500 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRFN340
A drop-in substitute for the IRFN340 must be the same N-channel type and offer a drain–source rating of at least 400 V, a continuous drain current rating of at least 10 A and an on-resistance no higher than 0.55 Ω if efficiency and heat matter.
Mechanically, check the replacement against the SMD1 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.
Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.
Frequently asked questions
What is the IRFN340?
The IRFN340 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 400 V drain-source and 10 A continuous drain current.
What is the maximum voltage of the IRFN340?
The IRFN340 has a maximum drain-source voltage (Vds) of 400 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRFN340 handle?
It is rated for 10 A of continuous drain current, with power dissipation limited to 125 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the IRFN340?
On-resistance (Rds(on)) is 0.55 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the IRFN340 come in?
It is listed in SMD1. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the IRFN340?
No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.
Key Specifications
| Type | MOSFET |
|---|---|
| Channel Type | N -Channel |
| Drain-Source Voltage (Vds) | 400 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 10 A |
| Drain-Source On-Resistance (Rds) | 0.55 |
| Rise Time (tr) | 92 |
| Output Capacitance (Coss) | 3500 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | SMD1 |
| Power Dissipation (Pd) | 125 W |
Equivalent & Replacement Parts
No verified equivalents are listed for IRFN340 yet.