IRLZ44L N-Channel 60V 50A MOSFET Equivalent & Substitute Parts

Part Overview

The IRLZ44L is an N-Channel metal oxide semiconductor field-effect transistor (MOSFET) rated for 60V drain-to-source voltage and 50A continuous drain current in a Through Hole TO-262-3 package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing production and maintenance applications.

The IRLZ44L serves in switching and amplification circuits where N-Channel MOSFETs with 60V ratings and high current capacity are required. Due to its obsolete status, alternative parts with compatible electrical and mechanical specifications are essential for design continuity and component sourcing.

Substiute Parts

IRLZ44L

Vishay SiliconixIn Stock: 1136IRLZ44L Datasheet

Current PartRFQ

HUF76423P3

onsemiIn Stock: 1435HUF76423P3 Datasheet

MFR RecommendedRFQ

IRFZ44EPBF

Infineon TechnologiesIn Stock: 10516IRFZ44EPBF Datasheet

MFR RecommendedRFQ

NDP6060

onsemiIn Stock: 1695NDP6060 Datasheet

MFR RecommendedRFQ

STP45NF06

STMicroelectronicsIn Stock: 8832STP45NF06 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRLZ44L is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Drain-to-Source Voltage (Vdss) must equal or exceed 60V
• Continuous Drain Current (Id) must equal or exceed 50A at 25°C
• Gate Threshold Voltage (Vgs(th)) must be compatible with existing drive circuits
• On-State Resistance (Rds On) must not significantly degrade circuit performance
• Operating temperature range must encompass -55°C to 175°C

Mechanical Compatibility Requirements:

• Mounting type must be Through Hole
• Package must be physically compatible with existing PCB layouts

The substitute parts listed below meet these electrical and mechanical criteria. However, package differences (TO-220-3 versus TO-262-3) represent a mechanical change that requires PCB layout modification. Parts are grouped by their ability to satisfy the core electrical parameters while noting package variations.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

IRFZ44EPBF (Infineon Technologies) provides the closest electrical match with 48A continuous drain current and 23mOhm on-state resistance. This part is rated for 110W power dissipation and features ROHS3 compliance. However, the product status is listed as "Not For New Designs," limiting its suitability for new applications. The TO-220AB package requires PCB layout modification from the original TO-262-3.

NDP6060 (onsemi) delivers 48A continuous drain current with 25mOhm on-state resistance and 100W power dissipation. This part maintains Active product status and ROHS3 compliance. The extended operating temperature range (-65°C to 175°C) provides additional margin. The TO-220-3 package requires PCB layout modification.

Secondary Substitutes (Reduced Current Rating):

STP45NF06 (STMicroelectronics) provides 38A continuous drain current with 28mOhm on-state resistance and 80W power dissipation. This part is Active and ROHS3 compliant. The reduced current rating (38A versus 50A) requires circuit analysis to confirm adequacy for the intended application. The TO-220 package requires PCB layout modification.

HUF76423P3 (onsemi) delivers 35A continuous drain current with 30mOhm on-state resistance and 85W power dissipation. This part is Active and ROHS3 compliant. The reduced current rating (35A versus 50A) represents the largest deviation from the original specification and requires thorough circuit validation. The TO-220-3 package requires PCB layout modification.

Compliance Considerations:

All substitute parts are ROHS3 compliant, whereas the IRLZ44L is RoHS non-compliant. This compliance improvement supports regulatory requirements for new and ongoing production. All parts maintain REACH Unaffected status and EAR99 export classification consistent with the original part.

Frequently Asked Questions (FAQ)

Q: Can I directly replace the IRLZ44L with any of these substitute parts without PCB modification?

A: No. The IRLZ44L uses a TO-262-3 package, while all substitute parts use TO-220 or TO-220AB packages. These packages have different pin configurations and physical dimensions, requiring PCB layout modification. Pin-to-pin electrical compatibility does not exist between these package types.

Q: Which substitute part most closely matches the IRLZ44L electrical specifications?

A: IRFZ44EPBF provides the closest match with 48A continuous drain current (versus 50A) and superior on-state resistance of 23mOhm. However, its "Not For New Designs" status limits recommendation for new applications. NDP6060 offers the best balance of electrical performance (48A, 25mOhm) with Active product status.

Q: What is the significance of the continuous drain current difference between the IRLZ44L (50A) and substitute parts (35A to 48A)?

A: The continuous drain current rating determines the maximum sustained current the device can conduct without exceeding thermal limits. Substitutes with lower ratings (HUF76423P3 at 35A, STP45NF06 at 38A) may require circuit analysis to confirm they can handle the intended load. Thermal management and duty cycle must be evaluated.

Q: Are all substitute parts RoHS compliant?

A: Yes. All four substitute parts are ROHS3 compliant, whereas the IRLZ44L is RoHS non-compliant. This represents an improvement in regulatory compliance for new production.

Q: How do gate charge differences affect circuit performance?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. The IRLZ44L has 66nC at 5V, while substitutes range from 34nC to 70nC at 10V. Lower gate charge reduces switching losses and allows faster switching speeds. Differences in gate charge may require adjustment of gate drive circuits, particularly in high-frequency applications.

Q: What does "Not For New Designs" mean for the IRFZ44EPBF?

A: This product status indicates that while the part is currently available, the manufacturer does not recommend its use in new circuit designs. Existing designs using this part may continue to receive support, but new applications should select parts with Active status such as NDP6060 or STP45NF06.

Q: Can I use a substitute part with lower current rating if my circuit only requires partial current capacity?

A: Potentially, but this requires detailed circuit analysis. The continuous drain current rating must accommodate the maximum sustained current in your application, including transient peaks and thermal conditions. Thermal modeling and worst-case analysis are necessary to confirm adequacy.

Q: How do the different gate threshold voltages affect drive circuit compatibility?

A: The IRLZ44L has a gate threshold voltage of 2V, while substitutes range from 3V to 4V. This affects the minimum gate voltage required to turn the device on. Existing gate drive circuits designed for 2V threshold may require adjustment or validation to ensure reliable switching with higher threshold voltage parts.

Q: What is the impact of input capacitance differences on switching performance?

A: Input capacitance (Ciss) affects gate charge and switching speed. The IRLZ44L has 3300pF at 25V, significantly higher than substitutes (980pF to 1800pF). Lower input capacitance in substitutes results in faster switching and reduced gate drive power requirements, which may improve overall circuit efficiency.