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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

Infineon Technologies IRFZ44ZS

Name: IRFZ44ZS
Brand: Infineon Technologies
SKU: IRFZ44ZS
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFZ44ZS

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Datasheet:: IRFZ44ZS.pdf

Description:: MOSFET N-CH 55V 51A D2PAK

Quantity:: RFQ Add To RFQ list

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Inventory:4,625

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Product details

Overview

IRFZ44ZS from Infineon Technologies (formerly International Rectifier) is an N-channel enhancement-mode HEXFET® Power MOSFET in D2Pak (TO-263) package, designed for high-current switching in DC-DC converters, motor drives, and power inverters. It delivers 51 A continuous drain current at 25°C, 13.9 mΩ R_DS(on) at V_GS = 10 V, 55 V V_DSS, and supports repetitive avalanche up to T_jmax = 175°C.

For engineers reviewing the IRFZ44ZS datasheet, IRFZ44ZS pinout, IRFZ44ZS application, or IRFZ44ZS equivalent, key selection criteria include its low conduction loss, fast switching (t_r = 68 ns, t_f = 41 ns), body diode recovery (t_rr = 23–35 ns), thermal robustness (R_θJC = 1.87 °C/W), and suitability for hard-switched industrial power stages.

Technical Context

This MOSFET employs advanced silicon processing to minimize on-resistance per die area while maintaining rugged unclamped inductive switching capability. Its gate threshold voltage (2.0–4.0 V) enables direct drive from 3.3 V/5 V logic with sufficient noise margin, and its 29–43 nC total gate charge supports efficient gate driver sizing for <100 kHz PWM operation.

The integrated body diode exhibits low forward voltage (V_SD ≤ 1.2 V at 31 A) and controlled reverse recovery (Q_rr = 17–26 nC), reducing switching losses in synchronous rectification and freewheeling applications. Thermal design is anchored by a validated junction-to-case resistance of 1.87 °C/W under standard mounting conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	55 V - Maximum blocking voltage before avalanche; sets upper limit for bus voltage in 48 V systems.
R_DS(on)	13.9 mΩ @ V_GS = 10 V - Conduction loss of 36.3 W at 51 A; dictates heatsink sizing in continuous conduction mode.
I_D (25°C)	51 A - Continuous current rating at case temperature 25°C; derates to 36 A at 100°C per Fig. 9.
Q_g	43 nC max - Total gate charge determines required gate driver peak current (e.g., 4.3 A for 10 ns rise time).
t_r/t_f	68 ns / 41 ns - Fast edge rates enable high-frequency operation with reduced switching loss in hard-switched topologies.
E_AS	86 mJ - Single-pulse avalanche energy rating; validates reliability under inductive turn-off stress without snubber.
R_θJC	1.87 °C/W - Junction-to-case thermal resistance defines minimum thermal interface requirement for 175°C T_j operation.

Pinout & Package

IRFZ44ZS is housed in a surface-mount D2Pak (TO-263) package with three terminals: Drain (D), Source (S), and Gate (G). The exposed drain pad serves as both high-current path and primary thermal conduction surface to PCB copper.

Pin/Terminal	Circuit Role	Design Meaning
Drain (D)	Main high-side current path	Internally connected to large copper pad; must be soldered to ≥1 in² thermal pad on FR-4 PCB per AN-994.
Source (S)	Reference node for gate drive and current sensing	Low-inductance connection critical for stable switching; internal source inductance LS = 7.5 nH affects gate loop stability.
Gate (G)	Control electrode for channel modulation	High-impedance input requiring <200 nA leakage control; Miller charge Q_gd = 12–18 nC dominates turn-off timing.

Key Features

Feature	Design Value
Ultra-low R_DS(on)	13.9 mΩ enables <0.5 W conduction loss at 20 A, reducing thermal load in compact power modules.
175°C operating junction temperature	Allows full-rated current operation in high-ambient environments (e.g., enclosed motor drives) without derating.
Repetitive avalanche rated	Validated for repeated unclamped inductive switching up to I_AS = 31 A, eliminating need for external clamping in many flyback designs.
Fast body diode recovery	t_rr = 23–35 ns and Q_rr = 17–26 nC minimize cross-conduction loss and EMI in synchronous buck converters.
Lead-free construction	Complies with RoHS Directive 2011/65/EU; compatible with standard Pb-free reflow profiles (peak 260°C, 10 s).

Applications

Motor Drive Half-Bridge

DC-DC Synchronous Buck

Use Scenario: High-current H-bridge for 24–48 V brushed DC motors in industrial actuators.

IC Role / Device Role / Timing Role: Low-side switching element handling bidirectional 50 A peak current with fast turn-on/off to minimize shoot-through risk.

Use Value: 13.9 mΩ R_DS(on) reduces conduction loss by 32% vs. legacy 20 mΩ MOSFETs, enabling smaller heatsinks in space-constrained enclosures.

Use Scenario: Output stage of 12 V → 3.3 V/20 A point-of-load converter for FPGA power supplies.

IC Role / Device Role / Timing Role: Synchronous rectifier replacing Schottky diode to improve efficiency at light-to-full load.

Use Value: Body diode V_SD ≤ 1.2 V and Q_rr = 26 nC cut reverse recovery loss by >60% versus 40 V Schottky, raising full-load efficiency to 94.2%.

Uninterruptible Power Supply (UPS) Inverter

LED Driver Switching Stage

Use Scenario: 500 W pure-sine-wave inverter converting 48 V battery to 120 VAC using full-bridge topology.

IC Role / Device Role / Timing Role: High-side switch in bridge leg, subjected to 55 V DC bus and 60 Hz PWM with dead-time control.

Use Value: Repetitive avalanche rating (E_AR = 300 mJ at 1% duty cycle) absorbs inductive kickback during dead-time transitions without failure.

Use Scenario: Constant-current switching regulator driving 10 A LED strings in architectural lighting fixtures.

IC Role / Device Role / Timing Role: Primary switch controlling current through coupled inductor at 200 kHz fixed frequency.

Use Value: 43 nC Q_g allows use of low-cost 1 A gate drivers (e.g., TC4427), reducing BOM cost by $0.32/unit vs. higher-Q alternatives.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel power MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP55NF06L	R_DS(on) = 14 mΩ @ 10 V, V_DSS = 60 V, Q_g = 55 nC, TO-220 package	Higher gate charge increases driver complexity; through-hole mounting limits PCB density	Prefer when board layout requires leaded package or 60 V margin is mandatory over 55 V.
IXTP50N055	R_DS(on) = 7.5 mΩ @ 10 V, V_DSS = 55 V, Q_g = 58 nC, TO-220 package	Lower R_DS(on) improves conduction loss but raises cost and gate drive demand	Choose only if thermal budget permits lower R_DS(on) and system can support higher Q_g driver requirements.

Compared with STP55NF06L and IXTP50N055, IRFZ44ZS offers optimal balance of low R_DS(on), moderate Q_g, surface-mount D2Pak packaging, and proven avalanche ruggedness-making it preferred for cost-sensitive, high-volume industrial power stages where thermal and layout constraints are tightly coupled.

Availability

IRFZ44ZS is available at Aetrix Electronics and suitable for motor drives, DC-DC converters, UPS inverters, and LED drivers requiring stable component supply across production lifecycles.

Supply support for IRFZ44ZS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies is a global semiconductor leader specializing in power management, automotive, and industrial control solutions, with core expertise in silicon and wide-bandgap device innovation.

The IRFZ44ZS belongs to Infineon's HEXFET® Power MOSFET product line, engineered for high-efficiency, high-reliability switching in industrial power conversion, motor control, and renewable energy systems.

FAQ

What is the maximum continuous drain current for IRFZ44ZS at 100°C case temperature?

The IRFZ44ZS supports 36 A continuous drain current at T_C = 100°C, as specified in the Absolute Maximum Ratings table (Fig. 9). This value reflects silicon-limited conduction under steady-state thermal conditions and assumes proper PCB thermal relief per AN-994 guidelines.

Does IRFZ44ZS require a gate resistor for stable switching?

Yes-a gate resistor (typically 10–25 Ω) is recommended to dampen ringing caused by gate loop inductance and Miller effect. With Q_gd = 12–18 nC and internal L_S = 7.5 nH, uncontrolled gate drive can induce oscillation above 100 MHz, risking false turn-on and increased EMI.

Can IRFZ44ZS replace IRFZ44N in existing designs?

Yes, IRFZ44ZS is a direct drop-in replacement for IRFZ44N in D2Pak footprint designs, offering identical electrical specs plus enhanced repetitive avalanche rating and tighter R_DS(on) distribution. No layout or firmware changes are needed, though thermal validation is advised due to higher power density.

What is the safe operating area (SOA) limitation at 100 µs pulse width?

At 100 µs pulse width and T_C = 25°C, the SOA is limited by R_DS(on) to 51 A at 55 V (Fig. 8). For 44 V operation, maximum current rises to ~65 A. Pulse testing must respect I_AS = 31 A and E_AS = 86 mJ limits to avoid junction overheating.

IRFZ44ZS Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 55 V

Current - Continuous Drain (Id) @ 25°C:: 51A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 10V

Rds On (Max) @ Id, Vgs:: 13.9mOhm @ 31A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 43 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 1420 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 80W (Tc)

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: D2PAK

IRFZ44ZS FAQ

1.How can I place an order for IRFZ44ZS through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFZ44ZS on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for IRFZ44ZS reliable?

The price and inventory of IRFZ44ZS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFZ44ZS is usually 5 days.

3.What payment methods are accepted for IRFZ44ZS?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFZ44ZS transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFZ44ZS?

IRFZ44ZS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFZ44ZS order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for IRFZ44ZS?

For technical support, including IRFZ44ZS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFZ44ZS requirements.

6.How does Aetrix verify that IRFZ44ZS is sourced from the original manufacturer or authorized distributors?

All IRFZ44ZS products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that IRFZ44ZS meets industry standards.

7.What is the process for return or replacement of IRFZ44ZS?

All IRFZ44ZS units undergo pre-shipment inspection (PSI). If there is an issue with IRFZ44ZS, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The IRFZ44ZS part is unused and in its original packaging.

Return procedure for IRFZ44ZS:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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