50N03 MOSFET — Specifications & Equivalents

About the 50N03

The 50N03 is a MOSFET with a drain–source voltage (V_DS) rating of 30 V and a continuous drain current (I_D) of 50 A. It can dissipate up to 60 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): 30 V
• Max continuous drain current (I_D): 50 A
• Power dissipation (P_D): 60 W
• Max junction temperature (T_J): 175 °C
• Package: TO252

Typical applications

With its 30 V drain–source rating the 50N03 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.

The 50 A current rating puts it in high-current territory, where conduction loss (I² × R_DS(on)) and thermal design usually matter more than switching loss. Budget for adequate copper area and a heatsink.

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

Choosing a replacement for the 50N03

A drop-in substitute for the 50N03 should match its polarity and offer a drain–source rating of at least 30 V and a continuous drain current rating of at least 50 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 50N03?

The 50N03 is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 30 V drain-source and 50 A continuous drain current.

What is the maximum voltage of the 50N03?

The 50N03 has a maximum drain-source voltage (Vds) of 30 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the 50N03 handle?

It is rated for 50 A of continuous drain current, with power dissipation limited to 60 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the 50N03 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 50N03?

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.