IRFSL38N20DPBF N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The IRFSL38N20DPBF is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 200V drain-to-source voltage with 43A continuous drain current at 25°C. This device features a Through Hole TO-262 package and is part of the HEXFET® series. The part is currently classified as Obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement continuity.

Substiute Parts

IRFSL38N20DPBF

Infineon TechnologiesIn Stock: 1233IRFSL38N20DPBF Datasheet

Current PartRFQ

IRFSL4127PBF

Infineon TechnologiesIn Stock: 1357IRFSL4127PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRFSL38N20DPBF is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• FET Type: N-Channel (polarity must be identical)
• Drain to Source Voltage (Vdss): 200 V (voltage rating must equal or exceed)
• Package / Case: TO-262-3 Long Leads, I2PAK, TO-262AA (physical and electrical footprint compatibility)
• Mounting Type: Through Hole (assembly method compatibility)

Performance Parameters for Functional Equivalence:

• Current - Continuous Drain (Id) @ 25°C: Substitute must support minimum 43A
• Rds On (Max): Lower or equal values indicate improved performance
• Gate Charge (Qg): Affects switching speed and driver requirements
• Input Capacitance (Ciss): Influences gate drive circuit design

The IRFSL4127PBF meets all mandatory matching criteria and exceeds performance specifications, making it a direct functional substitute for the obsolete IRFSL38N20DPBF.

Parameter Comparison

Engineering Selection Recommendations

The IRFSL4127PBF is the qualified substitute for the obsolete IRFSL38N20DPBF based on the following engineering criteria:

Voltage and Current Ratings: Both devices are rated for 200V Vdss. The IRFSL4127PBF provides 72A continuous drain current, exceeding the 43A requirement of the original part. This provides design margin for thermal and electrical stress conditions.

Package and Footprint Compatibility: Both parts use the TO-262-3 Long Leads package with identical pinout and mechanical dimensions, ensuring direct PCB compatibility without layout modifications.

Compliance and Certifications: Both parts are ROHS3 Compliant with MSL 1 (Unlimited) moisture sensitivity rating, maintaining equivalent environmental and handling requirements. Both carry REACH Unaffected and EAR99 ECCN classifications.

Product Status: The substitute part is in Active production status, ensuring long-term availability and supply chain continuity compared to the Obsolete status of the original part.

Gate Drive Considerations: The IRFSL4127PBF requires higher gate charge (150 nC vs. 91 nC) and has increased input capacitance (5380 pF vs. 2900 pF). Existing gate drive circuits must be evaluated to confirm adequate drive capability. Lower on-state resistance (22 mOhm vs. 54 mOhm) reduces conduction losses and heat dissipation requirements.

Frequently Asked Questions (FAQ)

Q: Can the IRFSL4127PBF be used as a direct replacement for the IRFSL38N20DPBF without PCB modifications?

A: Yes. Both devices use the TO-262-3 Long Leads package with identical pinout and mechanical footprint. No PCB layout changes are required for physical installation.

Q: What are the key electrical differences between these two parts?

A: The IRFSL4127PBF provides higher continuous drain current (72A vs. 43A), lower on-state resistance (22 mOhm vs. 54 mOhm), higher gate charge (150 nC vs. 91 nC), and higher input capacitance (5380 pF vs. 5380 pF). Voltage rating and gate threshold voltage remain identical at 200V and 5V respectively.

Q: Will my existing gate drive circuit work with the IRFSL4127PBF?

A: The higher gate charge and input capacitance of the IRFSL4127PBF require evaluation of the existing gate drive circuit. The drive circuit must supply sufficient current to charge the gate within the required switching time. Consult the gate drive circuit specifications and the IRFSL4127PBF datasheet to confirm compatibility.

Q: Is the IRFSL4127PBF available in the same packaging options as the IRFSL38N20DPBF?

A: Both parts are supplied in TO-262-3 Long Leads package. The IRFSL4127PBF is available in Tube packaging, while the original part was supplied in standard packaging. Both are Through Hole mounted devices with identical case dimensions.

Q: What is the product status difference, and why does it matter?

A: The IRFSL38N20DPBF is classified as Obsolete, indicating it is no longer in production and subject to limited availability. The IRFSL4127PBF is in Active production status, ensuring reliable long-term supply and continued manufacturer support.

Q: Are there any compliance or environmental differences between these parts?

A: No. Both parts are ROHS3 Compliant, carry MSL 1 (Unlimited) moisture sensitivity rating, are REACH Unaffected, and share the same EAR99 ECCN classification. Environmental and regulatory requirements are equivalent.

Q: How does the lower on-state resistance of the IRFSL4127PBF affect circuit performance?

A: Lower Rds On (22 mOhm vs. 54 mOhm) reduces conduction losses and heat dissipation in the device. This improves overall circuit efficiency and may reduce cooling requirements. The substitute part will operate cooler under identical load conditions.

Q: Can I use the IRFSL4127PBF in applications requiring lower current than 43A?

A: Yes. The IRFSL4127PBF is rated for 72A continuous drain current, so it can be used in applications requiring 43A or less. The higher current rating provides design margin and does not restrict use in lower-current applications.