SQD40N04-10A MOSFET — Specifications & Equivalents

About the SQD40N04-10A

The SQD40N04-10A is a MOSFET with a drain–source voltage (V_DS) rating of 40 V and a continuous drain current (I_D) of 42 A. It can dissipate up to 71 W and is rated to a junction temperature of 175 °C. It is supplied in the TO-252 package.

At a glance

• Type: MOSFET
• Max drain–source voltage (V_DS): 40 V
• Max continuous drain current (I_D): 42 A
• Power dissipation (P_D): 71 W
• Max junction temperature (T_J): 175 °C
• Package: TO-252

Typical applications

With its 40 V drain–source rating the SQD40N04-10A 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.

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 385 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the SQD40N04-10A

A drop-in substitute for the SQD40N04-10A should match its polarity and offer a drain–source rating of at least 40 V and a continuous drain current rating of at least 42 A.

Mechanically, check the replacement against the TO-252 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 SQD40N04-10A?

The SQD40N04-10A is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 40 V drain-source and 42 A continuous drain current.

What is the maximum voltage of the SQD40N04-10A?

The SQD40N04-10A has a maximum drain-source voltage (Vds) of 40 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the SQD40N04-10A handle?

It is rated for 42 A of continuous drain current, with power dissipation limited to 71 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the SQD40N04-10A come in?

It is listed in TO-252. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the SQD40N04-10A?

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.