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Infineon Technologies IRFZ44Z — Discrete Semiconductors

IRFZ44Z HEXFET N-Channel MOSFET, 55V 51A TO-220

MPNIRFZ44Z
Obsolete

Infineon HEXFET® series, IRFZ44Z, N-Channel MOSFET, 55 V drain-to-source, 51 A continuous drain at 25°C, 13.9 mOhm Rds(on) at 31 A and 10 V gate drive, 43 nC gate charge, TO-220-3 through-hole package, -55°C to 175°C junction temperature.

$0.9900Ref. price · indicative, final on quote
Infineon Technologies IRFZ44Z datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

IRFZ44Z specifications
ParameterValue
SeriesHEXFET®
FET typeN-Channel
MountingThrough Hole
Drain to source voltage55 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C51A (Tc)
Power dissipation80W (Tc)
Operating temperature-55°C~175°C(TJ)
PackageTube
Vgs±20V
TechnologyMOSFET (Metal Oxide)
CaseTO-220-3
Vgs(th) (Max) @ id4V @ 250µA
Rds on (Max) @ id, vgs13.9mOhm @ 31A, 10V
Gate charge (Qg) (Max) @ vgs43 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds1420 pF @ 25 V

Product details

The 80 W power dissipation limit at the case sets the thermal budget — real-world current derating depends on heatsink selection and ambient temperature, not just the headline 51 A figure.

Gate drive voltage — 10 V required for rated Rds(on)

This part specifies a drive voltage of 10 V for the maximum Rds(on) rating, with a gate threshold of 4 V maximum at 250 µA. A 5 V logic-level gate signal will not fully enhance the channel — expect on-resistance roughly double the 13.9 mOhm spec at 4.5 V drive.

MSL 1 out of the bag — no bake needed before reflow if stored dry.

For a new design or a BOM line that needs supply continuity, qualifying a current-production N-channel MOSFET in the same 55 V / 50 A class with a TO-220 footprint is the practical next step.

Frequently asked questions

Is IRFZ44Z obsolete?

Yes, the IRFZ44Z carries an obsolete lifecycle status. It is no longer in production and must be sourced through surplus or independent channels.

What is a direct replacement for IRFZ44Z?

No official successor is listed for the IRFZ44Z. A current-production N-channel MOSFET in the 55 V to 60 V range with a TO-220 package, 50 A+ continuous drain rating, and similar gate charge should be evaluated for pin-compatible fit and Rds(on) parity.