IRF542 MOSFET — Specifications & Equivalents
Manufacturer: Commonly produced by International Rectifier (now Infineon)
About the IRF542
The IRF542 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 100 V, a continuous drain current (ID) of 25 A and an on-resistance (RDS(on)) of 0.1 Ω. It can dissipate up to 125 W and is rated to a junction temperature of 150 °C. It is supplied in the TO220 package.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 100 V
- Max continuous drain current (ID): 25 A
- On-resistance (RDS(on)): 0.1 Ω
- Power dissipation (PD): 125 W
- Max junction temperature (TJ): 150 °C
- Package: TO220
- Manufacturer: Commonly produced by International Rectifier (now Infineon)
Typical applications
With its 100 V drain–source rating the IRF542 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 60 ns and an output capacitance (Coss) of 800 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the IRF542
A drop-in substitute for the IRF542 must be the same N-channel type and offer a drain–source rating of at least 100 V, a continuous drain current rating of at least 25 A and an on-resistance no higher than 0.1 Ω if efficiency and heat matter.
Mechanically, check the replacement against the TO220 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 IRF542?
The IRF542 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 100 V drain-source and 25 A continuous drain current.
What is the maximum voltage of the IRF542?
The IRF542 has a maximum drain-source voltage (Vds) of 100 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.
How much current can the IRF542 handle?
It is rated for 25 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 IRF542?
On-resistance (Rds(on)) is 0.1 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the IRF542 come in?
It is listed in TO220. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the IRF542?
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) | 100 V |
| Gate-Source Voltage (Vgs) | 20 V |
| Drain Current (Id) | 25 A |
| Drain-Source On-Resistance (Rds) | 0.1 |
| Rise Time (tr) | 60 |
| Output Capacitance (Coss) | 800 |
| Junction Temperature (Tj) | 150 °C |
| Package | TO220 |
| Power Dissipation (Pd) | 125 W |
Equivalent & Replacement Parts
No verified equivalents are listed for IRF542 yet.