IRLB3034 Pinout, Datasheet & Equivalents: The Complete Reference

What Is the IRLB3034?

The IRLB3034 is an N-channel power MOSFET rated for 40V and up to 343A, housed in a standard TO-220AB through-hole package. It was originally developed by International Rectifier (IR) as part of their HEXFET power MOSFET line; after Infineon Technologies acquired International Rectifier in 2015, the part continued production under the Infineon brand, now marketed within Infineon's StrongIRFET family — parts specifically optimized for very low on-resistance and high current handling in low-frequency switching applications.

What made this part stand out from ordinary power MOSFETs is its combination of an extremely low RDS(on) with a gate that can be fully driven at low, logic-level voltages (as low as 4.5V) — a combination that's genuinely useful, and part of why it developed a following well beyond its original industrial target applications, as covered later in this guide.

Full Datasheet Specifications

All figures below are pulled directly from Infineon's official product page and datasheet for the IRLB3034.

Why the "343A" Rating Is Misleading

Most secondhand descriptions of this part quote "343A" as if it's a usable continuous current rating. It isn't, and understanding why matters if you're actually sizing a circuit around this MOSFET rather than just quoting a spec sheet number.

Infineon's own datasheet lists two continuous drain current figures, not one:

• 343A — silicon-limited. This is the theoretical maximum the silicon die itself could handle if nothing else in the package were a limiting factor. It assumes ideal, unrealistic conditions.
• 195A — package-limited. This is the real ceiling once you account for the TO-220 package's bond wires and leads, which simply cannot carry 343A without failing regardless of how well the die is cooled.

195A is the number that reflects reality — and even that assumes a 25°C case temperature and near-ideal heatsinking, which is rarely achievable in a real enclosure. For any real design, treat 195A as a theoretical ceiling, not a target, and apply the derating guidance later in this article.

Is the IRLB3034 Still Available? Verified Replacements

As of this writing, the IRLB3034 (and its lead-free variant, the IRLB3034PBF) is listed as obsolete and no longer manufactured by major distributors. If you're specifying this part for a new design rather than working with stock you already have on hand, you'll need a replacement.

Infineon's officially recommended replacement, confirmed across multiple authorized distributor listings, is the IPP015N04NF2SAKMA1. A few other parts are commonly cited in the industry as functional substitutes, though these are not manufacturer-designated replacements:

If you're designing a new PCB around a replacement part, double-check its footprint and thermal pad requirements against your board layout before finalizing — TO-220 variants can differ slightly in lead spacing and tab dimensions between manufacturers. If you're not sure whether this is the only obsolete part hiding in an existing BOM, NextPCB's free BOM checker flags discontinued and hard-to-source parts before they hold up a production run.

Common Applications

The IRLB3034's low RDS(on) and logic-level gate drive also make power MOSFETs like this a common choice for the kind of external pass-transistor boost circuit discussed in our 78H24 pinout and voltage regulator guide — using a MOSFET to carry the bulk of the load current alongside a linear regulator is a well-established way to push a regulator's output current beyond its own rated maximum.

Why Hobbyists Search for This Part: Airsoft MOSFET Trigger Circuits

If you found this page searching for "3034 mosfet" rather than the full part number, there's a good chance you're not an industrial power electronics engineer — you're likely working on an airsoft gearbox upgrade. This part has a long-standing following in the airsoft hobbyist community, and it's worth explaining why, since most datasheets and distributor pages don't cover this use case at all.

Airsoft "MOSFET" upgrades add a MOSFET switching circuit between an airsoft gun's trigger contacts and its motor. Instead of the mechanical trigger contacts carrying the full motor current directly (which causes arcing and wear over time), the MOSFET carries the high current while the low-current trigger contacts just switch the MOSFET's gate. The IRLB3034's combination of logic-level gate drive (it switches on fully from the low voltages typical of airsoft battery packs) and very low RDS(on) (minimal heat buildup even at the high pulsed currents a gearbox motor draws) made it a popular, if somewhat oversized, choice for these builds.

If you're building or repairing a MOSFET trigger board for this kind of project, the same pinout, specs, and — importantly — the same 195A package-limited current ceiling from earlier in this guide apply. The part is genuinely overspecified for this application (a gearbox motor draws nowhere near 195A), which is part of why it became popular: the margin makes the circuit very forgiving of imperfect heatsinking in a tight gearbox shell.

Safe Design Margins

Whether you're working on an industrial design or a hobbyist project, the same general engineering practice applies: don't design against a part's absolute maximum ratings. A common rule of thumb is to keep continuous operating conditions at least 20% below the datasheet's absolute maximums — for the IRLB3034's package-limited current, that means treating roughly 150–156A as a practical continuous ceiling, not 195A, and leaving similar headroom on the 40V VDS rating. Combine this with a heatsink sized for your actual enclosure and ambient temperature, not just the datasheet's idealized case temperature.

FAQ

What is the pinout of the IRLB3034?

Facing the part with the branding toward you and pins pointing down, the three pins from left to right are Gate, Drain, and Source. The metal tab on the back is internally connected to Drain, standard for this TO-220 MOSFET family.

Is the IRLB3034 still in production?

No. The IRLB3034 and IRLB3034PBF are listed as obsolete by major distributors. Infineon's officially recommended replacement is the IPP015N04NF2SAKMA1.

What does the IRLB3034's 343A rating actually mean?

343A is the theoretical silicon-limited maximum, not a usable rating. The realistic ceiling is 195A (package-limited), and that figure assumes ideal case temperature and cooling that's rarely achievable in a real enclosure. Practical designs should derate well below even the 195A figure.

Why is the IRLB3034 popular for airsoft MOSFET builds?

Its logic-level gate drive and very low on-resistance make it easy to switch fully on from typical airsoft battery voltages while generating minimal heat, even though its current rating far exceeds what a gearbox motor actually draws. The large margin makes it forgiving of the imperfect heatsinking common in a compact gearbox shell.