IRFP440 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRFP440
The IRFP440 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 500 V, a continuous drain current (ID) of 8 A and an on-resistance (RDS(on)) of 0.85 Ω. It can dissipate up to 125 W and is rated to a junction temperature of 150 °C. It is supplied in the TO3P package.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 500 V
- Max continuous drain current (ID): 8 A
- On-resistance (RDS(on)): 0.85 Ω
- Power dissipation (PD): 125 W
- Max junction temperature (TJ): 150 °C
- Package: TO3P
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 500 V drain–source rating the IRFP440 sits in the high-voltage (offline) class of switching MOSFETs, typically found in primary-side switching in offline SMPS (flyback, forward and quasi-resonant), active PFC boost stages, half-bridge and full-bridge inverters, induction heating and electronic ballasts and BLDC and AC motor drives. The rating leaves usable margin above the ~325 V DC bus obtained by rectifying 230 VAC mains, which is why this class dominates offline power supplies.
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 23 ns and an output capacitance (Coss) of 154 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRFP440
A drop-in substitute for the IRFP440 must be the same N-channel type and offer a drain–source rating of at least 500 V, a continuous drain current rating of at least 8 A and an on-resistance no higher than 0.85 Ω if efficiency and heat matter.
Mechanically, check the replacement against the TO3P 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 IRFP440?
The IRFP440 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 500 V drain-source and 8 A continuous drain current.
What is the maximum voltage of the IRFP440?
The IRFP440 has a maximum drain-source voltage (Vds) of 500 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRFP440 handle?
It is rated for 8 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 IRFP440?
On-resistance (Rds(on)) is 0.85 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the IRFP440 come in?
It is listed in TO3P. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the IRFP440?
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) | 500 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 8 A |
| Drain-Source On-Resistance (Rds) | 0.85 |
| Rise Time (tr) | 23 nS |
| Output Capacitance (Coss) | 154 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | TO3P |
| Power Dissipation (Pd) | 125 W |
Equivalent & Replacement Parts
No verified equivalents are listed for IRFP440 yet.