IXFX25N90 Equivalent & Substitute Parts

Part Overview

The IXFX25N90 is an N-Channel 900V 25A MOSFET manufactured by IXYS in the HiPerFET™ series. This device is packaged in a TO-247-3 (PLUS247™-3) through-hole configuration and is rated for 560W maximum power dissipation at the case temperature. The part is currently classified as obsolete, making identification of equivalent and substitute components necessary for ongoing design support, maintenance, and production continuity.

Substiute Parts

IXFX25N90

IXYSIn Stock: 865IXFX25N90 Datasheet

Current PartRFQ

IXFX40N90P

IXYSIn Stock: 1131IXFX40N90P Datasheet

SimilarRFQ

STW20N95K5

STMicroelectronicsIn Stock: 9710STW20N95K5 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the IXFX25N90 is determined by the following critical electrical and mechanical parameters:

Voltage Rating: The drain-to-source voltage (Vdss) must be equal to or greater than 900V to maintain circuit protection margins.

Current Rating: The continuous drain current (Id) must meet or exceed 25A at 25°C to ensure the substitute can handle the design load without thermal stress.

On-State Resistance (Rds On): The maximum on-state resistance at 10V gate drive must be compatible with the thermal and efficiency requirements of the application. The IXFX25N90 specifies 330mOhm maximum.

Package and Mounting: The substitute must be compatible with TO-247-3 through-hole mounting to ensure mechanical and thermal interface compatibility.

Operating Temperature Range: The substitute must support the full -55°C to 150°C operating range.

Gate Drive Voltage: The substitute must operate with standard 10V gate drive voltage.

Based on these criteria, two substitute parts are identified:

1. IXFX40N90P — Higher current rating (40A) with improved on-state resistance (230mOhm), same voltage class, same package, active product status.
2. STW20N95K5 — Slightly higher voltage rating (950V), lower current rating (17.5A), same package, active product status with RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

IXFX40N90P is the primary substitute for direct replacement in applications where the IXFX25N90 is specified. This part maintains identical voltage rating (900V) and package configuration (TO-247-3 through-hole), while providing superior electrical performance through higher current capacity (40A versus 25A) and lower on-state resistance (230mOhm versus 330mOhm). The IXFX40N90P is an active product with current manufacturing support, ensuring long-term availability and supply chain stability. The increased power dissipation rating (960W versus 560W) provides additional thermal margin for demanding applications.

STW20N95K5 is an alternative substitute suitable for applications where current requirements are lower than the original design specification. This part offers a marginally higher voltage rating (950V versus 900V), providing enhanced voltage margin. The STW20N95K5 is manufactured by STMicroelectronics and carries RoHS3 compliance certification. However, the reduced continuous drain current (17.5A versus 25A) and lower power dissipation rating (250W versus 560W) restrict its use to designs with current demands below 17.5A. The significantly lower gate charge (40nC versus 240nC) and input capacitance (1500pF versus 10800pF) indicate faster switching characteristics, which may benefit high-frequency applications.

Both substitute parts are active products with RoHS3 compliance, ensuring regulatory alignment and supply continuity. Selection between IXFX40N90P and STW20N95K5 depends on application current requirements and thermal design constraints.

Frequently Asked Questions (FAQ)

Q: Can the IXFX40N90P directly replace the IXFX25N90 in all applications?

A: The IXFX40N90P is electrically and mechanically compatible with the IXFX25N90 for applications requiring up to 25A continuous drain current. The higher current rating (40A) and lower on-state resistance (230mOhm) of the IXFX40N90P provide performance improvement without introducing compatibility issues. The identical 900V voltage rating and TO-247-3 package ensure pin-for-pin and thermal interface compatibility.

Q: What are the key differences between IXFX40N90P and STW20N95K5?

A: The IXFX40N90P is optimized for higher current applications (40A continuous) with moderate switching speed, while the STW20N95K5 is designed for lower current applications (17.5A continuous) with faster switching characteristics. The IXFX40N90P maintains the same 900V voltage class as the original IXFX25N90, whereas the STW20N95K5 offers 950V rating. Gate charge and input capacitance differ significantly: IXFX40N90P has 230nC gate charge and 14000pF input capacitance, while STW20N95K5 has 40nC gate charge and 1500pF input capacitance, indicating substantially different switching dynamics.

Q: Is the STW20N95K5 suitable for applications originally designed for the IXFX25N90?

A: The STW20N95K5 is suitable only for applications where the continuous drain current requirement does not exceed 17.5A. Applications requiring the full 25A continuous current rating of the IXFX25N90 cannot use the STW20N95K5 without circuit redesign. The STW20N95K5 offers higher voltage margin (950V versus 900V) and faster switching characteristics, making it appropriate for lower-current, high-frequency designs.

Q: Are both substitute parts available in the same package configuration?

A: Yes, both IXFX40N90P and STW20N95K5 are available in TO-247-3 through-hole packages, ensuring mechanical and thermal interface compatibility with the original IXFX25N90. This package compatibility allows for direct socket substitution without PCB redesign.

Q: What is the significance of the product status difference between the IXFX25N90 and its substitutes?

A: The IXFX25N90 is classified as obsolete, indicating that the manufacturer has discontinued production and support. Both substitute parts (IXFX40N90P and STW20N95K5) are active products with ongoing manufacturing and supply chain support. Selection of an active product ensures long-term availability, technical support, and compliance with current regulatory standards.

Q: Do the substitute parts meet RoHS3 compliance requirements?

A: The IXFX40N90P and STW20N95K5 are both RoHS3 compliant. The original IXFX25N90 does not specify RoHS status. For applications requiring RoHS3 compliance, either substitute part is acceptable from a regulatory standpoint.

Q: How do gate charge differences affect circuit design?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. The IXFX25N90 requires 240nC at 10V gate drive, while the IXFX40N90P requires 230nC and the STW20N95K5 requires only 40nC. Lower gate charge reduces driver power dissipation and enables faster switching transitions. The STW20N95K5, with significantly lower gate charge, is advantageous in high-frequency switching applications where driver efficiency is critical.

Q: What thermal considerations apply when substituting these parts?

A: The IXFX40N90P has a higher power dissipation rating (960W) compared to the IXFX25N90 (560W), allowing operation at higher power levels with the same thermal interface. The STW20N95K5 has a lower power dissipation rating (250W), restricting its use to lower-power applications. All three parts operate across the same temperature range (-55°C to 150°C), ensuring thermal compatibility in the specified operating environment.