KDB15N50 MOSFET — Specifications & Equivalents

About the KDB15N50

The KDB15N50 is a MOSFET with a drain–source voltage (V_DS) rating of 500 V and a continuous drain current (I_D) of 15 A. It can dissipate up to 300 W and is rated to a junction temperature of 175 °C. It is supplied in the TO-263 package.

At a glance

• Type: MOSFET
• Max drain–source voltage (V_DS): 500 V
• Max continuous drain current (I_D): 15 A
• Power dissipation (P_D): 300 W
• Max junction temperature (T_J): 175 °C
• Package: TO-263

Typical applications

With its 500 V drain–source rating the KDB15N50 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 ±30 V maximum; exceeding it punctures the gate oxide and destroys the device permanently.

Switching behaviour is characterised by an output capacitance (C_oss) of 230 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the KDB15N50

A drop-in substitute for the KDB15N50 should match its polarity and offer a drain–source rating of at least 500 V and a continuous drain current rating of at least 15 A.

Mechanically, check the replacement against the TO-263 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 KDB15N50?

The KDB15N50 is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 500 V drain-source and 15 A continuous drain current.

What is the maximum voltage of the KDB15N50?

The KDB15N50 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 KDB15N50 handle?

It is rated for 15 A of continuous drain current, with power dissipation limited to 300 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the KDB15N50 come in?

It is listed in TO-263. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the KDB15N50?

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.