21N06 MOSFET — Specifications & Equivalents

About the 21N06

The 21N06 is a MOSFET with a drain–source voltage (V_DS) rating of 60 V and a continuous drain current (I_D) of 21 A. It can dissipate up to 45 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): 60 V
• Max continuous drain current (I_D): 21 A
• Power dissipation (P_D): 45 W
• Max junction temperature (T_J): 175 °C
• Package: TO252

Typical applications

With its 60 V drain–source rating the 21N06 sits in the mid-range class of switching MOSFETs, typically found in 24 V and 48 V industrial and battery systems, motor drives and H-bridges and load and hot-swap switching.

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

Choosing a replacement for the 21N06

A drop-in substitute for the 21N06 should match its polarity and offer a drain–source rating of at least 60 V and a continuous drain current rating of at least 21 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 21N06?

The 21N06 is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 60 V drain-source and 21 A continuous drain current.

What is the maximum voltage of the 21N06?

The 21N06 has a maximum drain-source voltage (Vds) of 60 V. Treat this as an absolute maximum and design with margin, especially when switching inductive loads.

How much current can the 21N06 handle?

It is rated for 21 A of continuous drain current, with power dissipation limited to 45 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the 21N06 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 21N06?

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.