SSM70T03J MOSFET — Specifications & Equivalents

About the SSM70T03J

The SSM70T03J is a MOSFET with a drain–source voltage (V_DS) rating of 30 V and a continuous drain current (I_D) of 60 A. It can dissipate up to 53 W and is rated to a junction temperature of 175 °C. It is supplied in the TO251 package.

At a glance

• Type: MOSFET
• Max drain–source voltage (V_DS): 30 V
• Max continuous drain current (I_D): 60 A
• Power dissipation (P_D): 53 W
• Max junction temperature (T_J): 175 °C
• Package: TO251

Typical applications

With its 30 V drain–source rating the SSM70T03J 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 60 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 245 pF, which together with the gate drive determines switching loss and the practical upper frequency limit.

Choosing a replacement for the SSM70T03J

A drop-in substitute for the SSM70T03J should match its polarity and offer a drain–source rating of at least 30 V and a continuous drain current rating of at least 60 A.

Mechanically, check the replacement against the TO251 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 SSM70T03J?

The SSM70T03J is a MOSFET (metal-oxide-semiconductor field-effect transistor). It is rated for 30 V drain-source and 60 A continuous drain current.

What is the maximum voltage of the SSM70T03J?

The SSM70T03J 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 SSM70T03J handle?

It is rated for 60 A of continuous drain current, with power dissipation limited to 53 W. Real-world capability depends on your heatsinking and ambient temperature.

What package does the SSM70T03J come in?

It is listed in TO251. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the SSM70T03J?

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.