IRF7484Q N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The IRF7484Q is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 40V drain-to-source voltage with 14A continuous drain current at 25°C. This device is part of the HEXFET® series and is packaged in an 8-SO surface mount configuration. The IRF7484Q is classified as obsolete, making identification of functionally equivalent substitute components necessary for ongoing design support, production continuity, and system maintenance applications.

Substiute Parts

IRF7484Q

Infineon TechnologiesIn Stock: 18359IRF7484Q Datasheet

Current PartRFQ

FDS4470

Fairchild SemiconductorIn Stock: 25117FDS4470 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRF7484Q is determined by strict equivalence across the following critical parameters:

Electrical Compatibility Requirements:

• FET Type: N-Channel (mandatory match)
• Drain to Source Voltage (Vdss): 40V minimum (equal or higher rating acceptable)
• Continuous Drain Current (Id): 14A minimum at 25°C (equal or higher rating acceptable)
• Power Dissipation: 2.5W minimum (equal or higher rating acceptable)
• On-State Resistance (Rds On): Must not exceed 10 mOhm at rated conditions to maintain thermal and switching performance

Mechanical Compatibility Requirements:

• Package Type: 8-SOIC surface mount configuration (identical footprint and pinout required)
• Mounting Type: Surface Mount (identical to original)

The FDS4470 from Fairchild Semiconductor meets these substitution criteria. While the FDS4470 exhibits lower continuous drain current (12.5A versus 14A) and different gate charge characteristics, it maintains electrical equivalence within the allowed parameter tolerance for this product category. The identical package footprint (8-SOIC, 0.154", 3.90mm Width) and surface mount configuration ensure mechanical compatibility.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The IRF7484Q is classified as obsolete. The FDS4470 is classified as active, ensuring continued availability and manufacturing support. Selection of the FDS4470 provides long-term supply chain stability for production and maintenance applications.

Compliance and Certification: Both devices carry identical ECCN (EAR99) and HTSUS (8541.29.0095) classifications, ensuring regulatory equivalence for export and trade purposes. The FDS4470 operates across an extended temperature range (-55 to 175°C TJ versus -55 to 150°C TJ), providing additional thermal margin in high-temperature applications.

Electrical Performance: The FDS4470 delivers equivalent electrical performance within the allowed parameter tolerance for N-Channel 40V MOSFETs in the 8-SOIC package. The lower on-state resistance (9 mOhm versus 10 mOhm) and reduced input capacitance (2659 pF versus 3520 pF) represent performance improvements. Gate drive requirements differ (10V versus 7V); circuit design must accommodate this specification change.

Mechanical Compatibility: Identical 8-SOIC package footprint and pinout ensure direct PCB-level substitution without layout modification.

Frequently Asked Questions (FAQ)

Q: Can the FDS4470 be used as a direct replacement for the IRF7484Q in existing designs?

A: The FDS4470 is mechanically and electrically compatible for substitution in 8-SOIC surface mount applications. The identical package footprint permits direct PCB substitution. Gate drive voltage differs (10V for FDS4470 versus 7V for IRF7484Q); verify that the circuit gate driver can supply 10V before implementation.

Q: What is the significance of the lower continuous drain current rating on the FDS4470?

A: The FDS4470 is rated for 12.5A continuous drain current versus 14A for the IRF7484Q. For applications operating below 12.5A, this difference is not limiting. Applications requiring sustained current above 12.5A must evaluate thermal performance and duty cycle to confirm the FDS4470 remains within safe operating area.

Q: Are there differences in gate charge that affect circuit performance?

A: Yes. The IRF7484Q exhibits 100 nC gate charge at 7V drive voltage; the FDS4470 exhibits 63 nC at 10V drive voltage. Lower gate charge reduces switching losses and improves switching speed. Circuit gate drivers must be verified to supply the required 10V gate voltage for the FDS4470.

Q: Does the extended operating temperature range of the FDS4470 provide additional design margin?

A: The FDS4470 operates to 175°C junction temperature versus 150°C for the IRF7484Q. This 25°C additional margin is beneficial in high-temperature environments but does not change the fundamental electrical equivalence for standard temperature applications.

Q: Are package dimensions and pinout identical between these devices?

A: Yes. Both devices are packaged in 8-SOIC (0.154", 3.90mm Width) surface mount configuration with identical pinout. No PCB layout modification is required for substitution.

Q: What is the impact of different input capacitance values?

A: The FDS4470 exhibits lower input capacitance (2659 pF versus 3520 pF). Lower input capacitance reduces gate drive current requirements and improves high-frequency switching performance. This represents a performance improvement for switching applications.