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Infineon Technologies IRFZ44ZS — Discrete Semiconductors

IRFZ44ZS MOSFET, N-Channel 55V 51A D2Pak, Obsolete

MPNIRFZ44ZS
Obsolete

Infineon HEXFET® IRFZ44ZS, N-Channel MOSFET, 55 V Vdss, 51 A Id, 13.9 mOhm Rds(on) @ 10 V, D2Pak (TO-263), -55°C to 175°C.

$2.8800Ref. price · indicative, final on quote
Infineon Technologies IRFZ44ZS datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

IRFZ44ZS specifications
ParameterValue
SeriesHEXFET®
FET typeN-Channel
MountingSurface Mount
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-263-3, D²Pak (2 Leads + Tab), TO-263AB
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 55 V Vdss rating gives you headroom for 12 V and 24 V systems, including load-dump transients in automotive environments. The 51 A continuous current rating is specified at case temperature 25°C — derate significantly at elevated temperatures; the 80 W power dissipation ceiling (at Tc=25°C) is the real thermal limit in a practical layout. The 13.9 mOhm Rds(on) at 10 V gate drive means conduction losses stay low for a 51 A part, but the gate threshold voltage (max 4 V at 250 µA) requires a full 10 V gate drive to achieve that low resistance — logic-level drive at 5 V will leave you with much higher on-resistance. Gate charge of 43 nC at 10 V is moderate; the driver needs to source that charge quickly for fast switching.

Lifecycle reality — obsolete, but still sourced

For new designs, a replacement should be selected.

The D2Pak (TO-263) is a surface-mount power package with three leads and a large metal tab.

Frequently asked questions

What is the replacement for IRFZ44ZS?

A functionally similar N-channel MOSFET with 55 V Vdss, 51 A Id, and D2Pak package would be a starting point for cross-referencing. Check parametric search tools for parts with similar Rds(on) and gate charge.

What are the specifications of IRFZ44ZS?

It comes in a D2Pak (TO-263) surface-mount package.

Where can I buy IRFZ44ZS?

The IRFZ44ZS is obsolete and not available through standard authorized distribution channels. It can be sourced through independent semiconductor distributors. Submit an RFQ to confirm current availability and pricing — quotes are provided on request.