FDA8440 N-Channel MOSFET 40V 30A/100A Equivalent & Substitute Parts

Part Overview

The FDA8440 is an N-Channel MOSFET manufactured by onsemi, rated for 40V drain-to-source voltage with continuous drain current of 30A (Ta) or 100A (Tc). This device features the PowerTrench® technology platform and is housed in a TO-3PN package for through-hole mounting applications. The FDA8440 is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement continuity.

Substiute Parts

FDA8440

onsemiIn Stock: 1611FDA8440 Datasheet

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IRFP4004PBF

Infineon TechnologiesIn Stock: 26057IRFP4004PBF Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDA8440 is based on the following critical electrical and mechanical parameters:

Voltage Rating Compatibility: The substitute part must maintain the same 40V Vdss rating to ensure safe operation within the original circuit design envelope.

Current Handling Capability: The substitute must support continuous drain current at or above the 100A (Tc) specification to maintain thermal performance equivalence.

On-State Resistance: The substitute's Rds On must be equal to or lower than the FDA8440 specification to prevent increased power dissipation and thermal stress.

Gate Drive Compatibility: The substitute must operate within the same gate voltage range (±20V maximum) and maintain compatible gate threshold voltage characteristics.

Thermal Performance: The substitute must support equivalent or superior power dissipation capability to ensure thermal management in the application.

Package and Mounting: The substitute must be compatible with through-hole mounting and physically compatible with the circuit board layout.

The IRFP4004PBF meets these substitution criteria through equivalent voltage rating, superior current handling, lower on-state resistance, compatible gate characteristics, and enhanced thermal performance.

Parameter Comparison

Engineering Selection Recommendations

The FDA8440 is classified as obsolete, making the IRFP4004PBF the primary substitute for ongoing applications. The IRFP4004PBF is classified as "Not For New Designs," indicating limited future availability; however, it provides superior electrical performance characteristics compared to the FDA8440.

Electrical Performance: The IRFP4004PBF delivers 195A continuous drain current versus the FDA8440's 100A, representing a 95% increase in current capacity. The on-state resistance is reduced to 1.7 mOhm compared to 2.1 mOhm, resulting in lower conduction losses. Gate charge is reduced to 330 nC from 450 nC, enabling faster switching characteristics. Input capacitance is significantly lower at 8920 pF versus 24740 pF, reducing gate drive requirements.

Thermal Management: Power dissipation capability increases to 380W from 306W, providing superior thermal headroom in the application.

Regulatory Compliance: Both devices maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity.

Package Consideration: The IRFP4004PBF uses TO-247AC packaging versus the FDA8440's TO-3PN. Physical board layout modifications are required to accommodate the different package footprint and pin configuration.

For applications requiring exact package compatibility with TO-3PN, alternative substitutes must be evaluated from the extended substitute list provided by the manufacturer.

Frequently Asked Questions (FAQ)

Q: Can the IRFP4004PBF directly replace the FDA8440 without circuit modifications?

A: The IRFP4004PBF is electrically compatible with the FDA8440 based on voltage rating, current capacity, and gate drive characteristics. However, the package change from TO-3PN to TO-247AC requires physical board layout modifications. Gate drive circuits may benefit from the reduced gate charge and input capacitance, but existing designs will function without gate driver changes.

Q: What is the significance of the lower on-state resistance in the IRFP4004PBF?

A: The reduction from 2.1 mOhm to 1.7 mOhm decreases conduction losses during the on-state, resulting in lower power dissipation and reduced thermal stress. This improvement is particularly beneficial in high-current applications operating near the 100A continuous rating of the FDA8440.

Q: Why is the gate charge specification important for substitution?

A: Gate charge directly affects switching speed and gate driver power requirements. The IRFP4004PBF's 330 nC specification versus the FDA8440's 450 nC represents a 27% reduction, enabling faster switching transitions and reduced gate driver stress. Existing gate drivers designed for the FDA8440 will operate more efficiently with the IRFP4004PBF.

Q: Are there package-compatible alternatives to the IRFP4004PBF?

A: The IRFP4004PBF uses TO-247AC packaging. Applications requiring TO-3PN package compatibility must reference the extended substitute list or consult with the component manufacturer for package-specific alternatives.

Q: What is the impact of reduced input capacitance on circuit design?

A: The IRFP4004PBF's input capacitance of 8920 pF is 64% lower than the FDA8440's 24740 pF. This reduction decreases the capacitive load on the gate driver, enabling faster switching transitions and reducing gate driver power dissipation. Existing gate driver designs will experience improved performance margins.

Q: Are both devices suitable for new design implementations?

A: The FDA8440 is obsolete and unsuitable for new designs. The IRFP4004PBF is classified as "Not For New Designs," indicating limited future availability. For new design implementations, consultation with the manufacturer is recommended to identify actively supported alternatives with long-term availability.

Q: What regulatory certifications apply to both devices?

A: Both the FDA8440 and IRFP4004PBF maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory continuity for applications subject to these requirements.