IRF4905L MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRF4905L
The IRF4905L is a P-channel MOSFET with a drain–source voltage (VDS) rating of 55 V, a continuous drain current (ID) of 74 A and an on-resistance (RDS(on)) of 0.02 Ω. It can dissipate up to 200 W and is rated to a junction temperature of 175 °C. It is supplied in the TO262 package.
At a glance
- Type: P-channel MOSFET
- Max drain–source voltage (VDS): 55 V
- Max continuous drain current (ID): 74 A
- On-resistance (RDS(on)): 0.02 Ω
- Power dissipation (PD): 200 W
- Max junction temperature (TJ): 175 °C
- Package: TO262
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 55 V drain–source rating the IRF4905L sits in the low-voltage class of switching MOSFETs, typically found in 12 V and 24 V automotive and industrial rails, synchronous buck converters, load switching and reverse-polarity protection and H-bridges for small motors.
The 74 A current rating puts it in high-current territory, where conduction loss (I² × RDS(on)) and thermal design usually matter more than switching loss. Budget for adequate copper area and a heatsink.
The low 0.02 Ω on-resistance keeps conduction loss down, which suits synchronous rectification and continuous high-current paths.
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 99 ns and an output capacitance (Coss) of 1400 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRF4905L
A drop-in substitute for the IRF4905L must be the same P-channel type and offer a drain–source rating of at least 55 V, a continuous drain current rating of at least 74 A and an on-resistance no higher than 0.02 Ω if efficiency and heat matter.
Mechanically, check the replacement against the TO262 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 IRF4905L?
The IRF4905L is a P-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 55 V drain-source and 74 A continuous drain current.
What is the maximum voltage of the IRF4905L?
The IRF4905L has a maximum drain-source voltage (Vds) of 55 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRF4905L handle?
It is rated for 74 A of continuous drain current, with power dissipation limited to 200 W. Real-world capability depends on your heatsinking and ambient temperature.
What is the on-resistance of the IRF4905L?
On-resistance (Rds(on)) is 0.02 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the IRF4905L come in?
It is listed in TO262. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the IRF4905L?
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 | P -Channel |
| Drain-Source Voltage (Vds) | 55 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 74 A |
| Drain-Source On-Resistance (Rds) | 0.02 |
| Rise Time (tr) | 99 nS |
| Output Capacitance (Coss) | 1400 pF |
| Junction Temperature (Tj) | 175 °C |
| Package | TO262 |
| Power Dissipation (Pd) | 200 W |
Equivalent & Replacement Parts
No verified equivalents are listed for IRF4905L yet.