IRFP251 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRFP251
The IRFP251 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 150 V, a continuous drain current (ID) of 33 A and an on-resistance (RDS(on)) of 0.085 Ω. It can dissipate up to 180 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): 150 V
- Max continuous drain current (ID): 33 A
- On-resistance (RDS(on)): 0.085 Ω
- Power dissipation (PD): 180 W
- Max junction temperature (TJ): 150 °C
- Package: TO3P
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 150 V drain–source rating the IRFP251 sits in the medium-voltage class of switching MOSFETs, typically found in 48 V and 96 V distribution systems, solar and telecom power stages, DC motor drives and intermediate-bus DC-DC converters.
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 120 ns and an output capacitance (Coss) of 650 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRFP251
A drop-in substitute for the IRFP251 must be the same N-channel type and offer a drain–source rating of at least 150 V, a continuous drain current rating of at least 33 A and an on-resistance no higher than 0.085 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 IRFP251?
The IRFP251 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 150 V drain-source and 33 A continuous drain current.
What is the maximum voltage of the IRFP251?
The IRFP251 has a maximum drain-source voltage (Vds) of 150 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRFP251 handle?
It is rated for 33 A of continuous drain current, with power dissipation limited to 180 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the IRFP251?
On-resistance (Rds(on)) is 0.085 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the IRFP251 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 IRFP251?
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) | 150 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 33 A |
| Drain-Source On-Resistance (Rds) | 0.085 |
| Rise Time (tr) | 120 nS |
| Output Capacitance (Coss) | 650 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | TO3P |
| Power Dissipation (Pd) | 180 W |
Equivalent & Replacement Parts
No verified equivalents are listed for IRFP251 yet.