UF540 MOSFET — Specifications & Equivalents
About the UF540
The UF540 is an N-channel MOSFET with a drain–source voltage (VDS) rating of 100 V, a continuous drain current (ID) of 27 A and an on-resistance (RDS(on)) of 0.085 Ω. It can dissipate up to 125 W and is rated to a junction temperature of 150 °C. It is supplied in the TO-220 package.
At a glance
- Type: N-channel MOSFET
- Max drain–source voltage (VDS): 100 V
- Max continuous drain current (ID): 27 A
- On-resistance (RDS(on)): 0.085 Ω
- Power dissipation (PD): 125 W
- Max junction temperature (TJ): 150 °C
- Package: TO-220
Typical applications
With its 100 V drain–source rating the UF540 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 35 ns and an output capacitance (Coss) of 250 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the UF540
A drop-in substitute for the UF540 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 27 A and an on-resistance no higher than 0.085 Ω if efficiency and heat matter.
Mechanically, check the replacement against the TO-220 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 UF540?
The UF540 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 100 V drain-source and 27 A continuous drain current.
What is the maximum voltage of the UF540?
The UF540 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 UF540 handle?
It is rated for 27 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 UF540?
On-resistance (Rds(on)) is 0.085 Ω. Multiply by the square of your load current to estimate conduction loss.
What package does the UF540 come in?
It is listed in TO-220. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the UF540?
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) | 27 A |
| Drain-Source On-Resistance (Rds) | 0.085 |
| Rise Time (tr) | 35 nS |
| Output Capacitance (Coss) | 250 pF |
| Junction Temperature (Tj) | 150 °C |
| Package | TO-220 |
| Power Dissipation (Pd) | 125 W |
Equivalent & Replacement Parts
No verified equivalents are listed for UF540 yet.