IRLR3103 Equivalent & Substitute Parts Reference

Part Overview

The IRLR3103 is an N-Channel 30V 55A MOSFET manufactured by Infineon Technologies in the HEXFET® series, housed in a TO-252AA (DPAK) surface mount package. This device is rated for 107W power dissipation and features a maximum on-resistance of 19mOhm at 33A and 10V gate-source voltage. The part is currently classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement.

Substiute Parts

IRLR3103

Infineon TechnologiesIn Stock: 17164IRLR3103 Datasheet

Current PartRFQ

AOD480

Alpha & Omega Semiconductor Inc.In Stock: 19766AOD480 Datasheet

MFR RecommendedRFQ

STD26P3LLH6

STMicroelectronicsIn Stock: 10461STD26P3LLH6 Datasheet

MFR RecommendedRFQ

STD35NF3LLT4

STMicroelectronicsIn Stock: 7558STD35NF3LLT4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IRLR3103 is determined by the following criteria:

Primary Matching Parameters:

• FET Type: N-Channel (required)
• Drain to Source Voltage (Vdss): 30V (required)
• Package: TO-252-3 (DPAK) surface mount (required for mechanical compatibility)
• Operating Temperature Range: -55°C to 175°C (required)

Secondary Performance Parameters:

• Continuous Drain Current (Id): Minimum 55A at 25°C (required for current handling equivalence)
• On-Resistance (Rds On): Maximum 19mOhm or lower at specified gate voltage (required for thermal and efficiency equivalence)
• Power Dissipation: Minimum 107W (required for thermal management equivalence)

Compliance Parameters:

• RoHS Status: Compliance preferred for new designs
• Moisture Sensitivity Level (MSL): Level 1 (Unlimited)

From the provided substitute list, the following parts meet the N-Channel 30V DPAK criteria:

• AOD480: N-Channel 30V 25A MOSFET (current rating below requirement; not equivalent)
• STD26P3LLH6: P-Channel 30V 12A MOSFET (incorrect channel type; not equivalent)
• STD35NF3LLT4: N-Channel 30V 35A MOSFET (meets channel type, voltage, and package; current rating below requirement but closest match)

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalence Assessment:

No part from the provided substitute list achieves full electrical equivalence to the IRLR3103. The primary limitation is continuous drain current rating:

• AOD480 provides only 25A continuous drain current, representing 45% of the IRLR3103 specification. This part is unsuitable for applications requiring the full 55A rating.

• STD35NF3LLT4 provides 35A continuous drain current, representing 64% of the IRLR3103 specification. While this part shares identical Vdss (30V), package type (TO-252-3 DPAK), and comparable on-resistance characteristics (19.5mOhm vs. 19mOhm), the current rating deficit of 20A is significant for high-current applications.

Compliance Considerations:

Both AOD480 and STD35NF3LLT4 carry ROHS3 compliance status, whereas the IRLR3103 is RoHS non-compliant. For new designs subject to RoHS requirements, either substitute provides regulatory advantage despite electrical limitations.

Product Status Impact:

Both substitute parts carry obsolescence or restricted status (AOD480: Not For New Designs; STD35NF3LLT4: Obsolete), limiting their suitability for long-term production programs.

Frequently Asked Questions (FAQ)

Q: Can AOD480 directly replace IRLR3103 in existing designs?

A: No. The AOD480 is rated for 25A continuous drain current versus the IRLR3103's 55A rating. Applications requiring the full 55A specification will experience current limiting and potential thermal stress with AOD480. Use only in designs where actual operating current does not exceed 25A.

Q: Is STD35NF3LLT4 a suitable alternative for IRLR3103?

A: STD35NF3LLT4 shares the same 30V Vdss, TO-252-3 DPAK package, and comparable on-resistance (19.5mOhm). However, its 35A continuous drain current rating is 20A below the IRLR3103 specification. This part is suitable only for applications where actual operating current does not exceed 35A. Thermal performance will be reduced due to lower power dissipation rating (50W vs. 107W).

Q: Why is STD26P3LLH6 listed but not recommended?

A: STD26P3LLH6 is a P-Channel MOSFET, whereas IRLR3103 is N-Channel. These devices have opposite polarity and are not interchangeable. P-Channel and N-Channel MOSFETs serve different circuit functions and cannot substitute for one another.

Q: What package compatibility exists between these parts?

A: IRLR3103, AOD480, and STD35NF3LLT4 all use TO-252-3 (DPAK) surface mount packaging with identical pinout (2 leads + tab). Physical board-level compatibility is confirmed. However, electrical parameter differences must be evaluated for each application.

Q: Are there RoHS compliance advantages to using substitutes?

A: Yes. Both AOD480 and STD35NF3LLT4 carry ROHS3 compliance certification, whereas IRLR3103 is RoHS non-compliant. For applications subject to RoHS directives, either substitute provides regulatory compliance. This advantage must be weighed against electrical parameter limitations.

Q: What is the impact of different gate threshold voltages?

A: IRLR3103 has Vgs(th) of 1V maximum, while both AOD480 and STD35NF3LLT4 have 2.5V maximum. Higher threshold voltage requires greater gate drive voltage to achieve full on-state conduction. Circuits designed for 1V threshold may require gate driver adjustment when using substitutes with 2.5V threshold.

Q: Can these parts be used in parallel to achieve higher current ratings?

A: Parallel operation of MOSFETs with different on-resistance characteristics (19mOhm vs. 23mOhm vs. 19.5mOhm) introduces current sharing imbalance. This practice is not recommended without additional current-sharing circuitry and thermal management analysis.