40N10K MOSFET — Specifications & Equivalents

About the 40N10K

The 40N10K is a MOSFET with a drain–source voltage (V_DS) rating of 100 V and a continuous drain current (I_D) of 40 A. It can dissipate up to 140 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 (V_DS): 100 V
• Max continuous drain current (I_D): 40 A
• Power dissipation (P_D): 140 W
• Max junction temperature (T_J): 175 °C
• Package: TO252

Typical applications

With its 100 V drain–source rating the 40N10K 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 (C_oss) of 290 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the 40N10K

A drop-in substitute for the 40N10K should match its polarity and offer a drain–source rating of at least 100 V and a continuous drain current rating of at least 40 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 40N10K?

The 40N10K is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 100 V drain-source and 40 A continuous drain current.

What is the maximum voltage of the 40N10K?

The 40N10K 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 40N10K handle?

It is rated for 40 A of continuous drain current, with power dissipation limited to 140 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the 40N10K 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 40N10K?

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.