K4018 MOSFET — Specifications & Equivalents
About the K4018
The K4018 is a MOSFET with a drain–source voltage (VDS) rating of 100 V and a continuous drain current (ID) of 25 A. It can dissipate up to 83 W and is rated to a junction temperature of 175 °C. It is supplied in the TO252 package.
At a glance
- Type: MOSFET
- Max drain–source voltage (VDS): 100 V
- Max continuous drain current (ID): 25 A
- Power dissipation (PD): 83 W
- Max junction temperature (TJ): 175 °C
- Package: TO252
Typical applications
With its 100 V drain–source rating the K4018 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 an output capacitance (Coss) of 180 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.
Choosing a replacement for the K4018
A drop-in substitute for the K4018 should match its polarity and offer a drain–source rating of at least 100 V and a continuous drain current rating of at least 25 A.
Mechanically, check the replacement against the TO252 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 K4018?
The K4018 is a 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 K4018?
The K4018 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 K4018 handle?
It is rated for 25 A of continuous drain current, with power dissipation limited to 83 W. Real-world capability depends on your heatsinking and ambient temperature.
What package does the K4018 come in?
It is listed in TO252. Verify the pinout of the specific variant, as one outline can carry different pin assignments.
What can I use to replace the K4018?
This page lists 17 candidate equivalents matched on electrical ratings and package. Any replacement should meet or exceed the original voltage, current and dissipation figures and use a compatible drive level.
Key Specifications
| Pd ⓘ - Maximum Power Dissipation | 83 W |
|---|---|
| |Vds|ⓘ - Maximum Drain-Source Voltage | 100 V |
| |Vgs|ⓘ - Maximum Gate-Source Voltage | 20 V |
| |Id| ⓘ - Maximum Drain Current | 25 A |
| Tj ⓘ - Maximum Junction Temperature | 175 °C |
| Cossⓘ - Output Capacitance | 180 pF |
| Package | TO252 |
| isc N-Channel MOSFET Transistor 2SK4018FEATURESDrain Current | I = 3.0A@ T =25D CDrain Source Voltage: V = 100V(Min)DSSStatic Drain-Source On-Resistance: R = 0.35(Max) @ V = 10VDS(on) GS100% avalanche testedMinimum Lot-to-Lot variations for robust deviceperformance and reliable operationDESCRIPTIONmotor drive, DC-DC converter, power switchand solen |