30N50 MOSFET — Specifications & Equivalents

About the 30N50

The 30N50 is an N-channel MOSFET with a drain–source voltage (V_DS) rating of 500 V, a continuous drain current (I_D) of 30 A and an on-resistance (R_DS(on)) of 0.25 Ω. It can dissipate up to 300 W and is rated to a junction temperature of 150 °C. It is supplied in the TO3PN package.

At a glance

• Type: N-channel MOSFET
• Max drain–source voltage (V_DS): 500 V
• Max continuous drain current (I_D): 30 A
• On-resistance (R_DS(on)): 0.25 Ω
• Power dissipation (P_D): 300 W
• Max junction temperature (T_J): 150 °C
• Package: TO3PN

Typical applications

With its 500 V drain–source rating the 30N50 sits in the high-voltage (offline) class of switching MOSFETs, typically found in primary-side switching in offline SMPS (flyback, forward and quasi-resonant), active PFC boost stages, half-bridge and full-bridge inverters, induction heating and electronic ballasts and BLDC and AC motor drives. The rating leaves usable margin above the ~325 V DC bus obtained by rectifying 230 VAC mains, which is why this class dominates offline power supplies.

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.

Choosing a replacement for the 30N50

A drop-in substitute for the 30N50 must be the same N-channel type and offer a drain–source rating of at least 500 V, a continuous drain current rating of at least 30 A and an on-resistance no higher than 0.25 Ω if efficiency and heat matter.

Mechanically, check the replacement against the TO3PN 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 30N50?

The 30N50 is an N-channel MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 500 V drain-source and 30 A continuous drain current.

What is the maximum voltage of the 30N50?

The 30N50 has a maximum drain-source voltage (Vds) of 500 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the 30N50 handle?

It is rated for 30 A of continuous drain current, with power dissipation limited to 300 W. Real-world capability depends on your heatsinking and ambient temperature.

What is the on-resistance of the 30N50?

On-resistance (Rds(on)) is 0.25 Ω. Multiply by the square of your load current to estimate conduction loss.

What package does the 30N50 come in?

It is listed in TO3PN. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the 30N50?

No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.