5P40 MOSFET — Specifications & Equivalents

About the 5P40

The 5P40 is a MOSFET with a drain–source voltage (V_DS) rating of 40 V and a continuous drain current (I_D) of 5.3 A. It can dissipate up to 2 W and is rated to a junction temperature of 150 °C. It is supplied in the SOT23-3L package.

At a glance

• Type: MOSFET
• Max drain–source voltage (V_DS): 40 V
• Max continuous drain current (I_D): 5.3 A
• Power dissipation (P_D): 2 W
• Max junction temperature (T_J): 150 °C
• Package: SOT23-3L

Typical applications

With its 40 V drain–source rating the 5P40 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 90 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the 5P40

A drop-in substitute for the 5P40 should match its polarity and offer a drain–source rating of at least 40 V and a continuous drain current rating of at least 5.3 A.

Mechanically, check the replacement against the SOT23-3L 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 5P40?

The 5P40 is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 40 V drain-source and 5.3 A continuous drain current.

What is the maximum voltage of the 5P40?

The 5P40 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 5P40 handle?

It is rated for 5.3 A of continuous drain current, with power dissipation limited to 2 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the 5P40 come in?

It is listed in SOT23-3L. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the 5P40?

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.