IXFP4N85X N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The IXFP4N85X is an N-Channel MOSFET manufactured by IXYS, rated for 850V drain-to-source voltage with 3.5A continuous drain current at 25°C. This device is part of the HiPerFET™ Ultra X series and is designed for high-voltage switching applications in through-hole TO-220AB packaging. The part is currently active in production with full RoHS3 compliance and unlimited moisture sensitivity rating.

Substitute parts are necessary when the original IXFP4N85X is unavailable, when design requirements demand alternative voltage or current ratings, or when supply chain optimization requires qualified alternatives from different manufacturers. All substitute parts listed maintain compatibility with the original mounting package and electrical drive requirements while offering variations in voltage rating, current capacity, and power dissipation characteristics.

Substiute Parts

IXFP4N85X

IXYSIn Stock: 18379IXFP4N85X Datasheet

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STP5N95K5

STMicroelectronicsIn Stock: 3658STP5N95K5 Datasheet

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STP6NK90Z

STMicroelectronicsIn Stock: 7818STP6NK90Z Datasheet

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STP7N105K5

STMicroelectronicsIn Stock: 2196STP7N105K5 Datasheet

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STP8NK100Z

STMicroelectronicsIn Stock: 1498STP8NK100Z Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IXFP4N85X is determined by the following criteria:

Primary Compatibility Requirements:

• FET Type: N-Channel (all substitutes must be N-Channel)
• Mounting Type: Through Hole (all substitutes must be through-hole)
• Package Case: TO-220-3 (all substitutes must use TO-220 family packaging)
• Drive Voltage: 10V gate drive (all substitutes must support 10V drive)
• Gate Voltage Maximum: ±30V (all substitutes must support ±30V maximum gate voltage)
• Operating Temperature Range: -55°C to 150°C (all substitutes must support this range)
• Compliance: RoHS3 compliant, REACH unaffected, MSL 1 (unlimited)

Electrical Parameter Flexibility: Substitutes may vary in Drain-to-Source Voltage (Vdss), Continuous Drain Current (Id), On-State Resistance (Rds On), Power Dissipation, and Gate Charge characteristics. These variations allow selection based on specific application requirements while maintaining functional compatibility with the original circuit topology.

All four substitute parts meet the primary compatibility requirements and are qualified alternatives for the IXFP4N85X.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts are active products with full RoHS3 compliance and REACH unaffected status, matching the regulatory and environmental compliance profile of the IXFP4N85X.

STP5N95K5 provides equivalent continuous drain current (3.5A) with a higher voltage rating (950V). This part is suitable for applications requiring higher voltage margin while maintaining identical current capacity. Power dissipation is reduced to 70W, which may limit use in high-power applications.

STP6NK90Z offers increased continuous drain current (5.8A) at a slightly higher voltage rating (900V) with comparable power dissipation (140W). This part accommodates higher current demands while maintaining voltage compatibility within the 850V design envelope.

STP7N105K5 provides a higher voltage rating (1050V) with increased current capacity (4A) and reduced on-state resistance (2Ω @ 2A). This part is suitable for designs requiring higher voltage headroom with moderate current increases.

STP8NK100Z delivers the highest current capacity (6.5A) and voltage rating (1000V) with the lowest on-state resistance (1.85Ω @ 3.15A) and highest power dissipation (160W). This part accommodates the most demanding current and power requirements while maintaining voltage compatibility.

Selection should be based on application-specific requirements for voltage rating, current capacity, and thermal management capability. All parts maintain compatibility with 10V gate drive and ±30V gate voltage specifications.

Frequently Asked Questions (FAQ)

Q: Can the STP5N95K5 be used as a direct replacement for the IXFP4N85X?

A: The STP5N95K5 is electrically compatible with the IXFP4N85X in terms of continuous drain current (3.5A), gate drive voltage (10V), and operating temperature range (-55°C to 150°C). Both devices use TO-220 through-hole packaging and are RoHS3 compliant. However, the STP5N95K5 has a lower maximum power dissipation rating (70W versus 150W), which may limit its use in high-power applications. The higher voltage rating (950V) provides additional voltage margin.

Q: What is the difference between the IXFP4N85X and STP6NK90Z in terms of current handling?

A: The STP6NK90Z supports 5.8A continuous drain current compared to the IXFP4N85X at 3.5A. This represents a 66% increase in current capacity. The STP6NK90Z also has lower on-state resistance (2Ω @ 2.9A versus 2.5Ω @ 2A), resulting in reduced conduction losses. Both devices operate at comparable voltage ratings (900V versus 850V) and power dissipation levels (140W versus 150W).

Q: Are all substitute parts compatible with the same PCB footprint as the IXFP4N85X?

A: All substitute parts use TO-220 through-hole packaging with TO-220-3 case configuration, which is mechanically compatible with the IXFP4N85X TO-220AB footprint. Pin spacing and mounting hole locations are identical across all listed parts. No PCB redesign is required for mechanical compatibility.

Q: Which substitute part has the lowest on-state resistance?

A: The STP8NK100Z has the lowest on-state resistance at 1.85Ω measured at 3.15A and 10V gate voltage. This represents a 26% reduction compared to the IXFP4N85X (2.5Ω @ 2A, 10V). Lower on-state resistance reduces conduction losses and heat generation during switching operations.

Q: What is the gate charge difference between the IXFP4N85X and the substitute parts?

A: The IXFP4N85X has a gate charge of 7 nC @ 10V, which is the lowest among all listed parts. The STP5N95K5 has 12.5 nC, STP7N105K5 has 17 nC, STP6NK90Z has 60.5 nC, and STP8NK100Z has 102 nC. Higher gate charge increases driver power requirements and switching losses. Selection should consider gate driver capability and switching frequency requirements.

Q: Can the STP8NK100Z replace the IXFP4N85X in a 850V application?

A: The STP8NK100Z is rated for 1000V drain-to-source voltage, which exceeds the 850V requirement of the IXFP4N85X. This provides additional voltage margin and safety headroom. The STP8NK100Z supports higher current (6.5A versus 3.5A) and has lower on-state resistance (1.85Ω versus 2.5Ω). Compatibility is confirmed for gate drive voltage (10V), operating temperature (-55°C to 150°C), and packaging (TO-220 through-hole). The higher power dissipation rating (160W versus 150W) accommodates increased current handling.

Q: What compliance certifications do all substitute parts share with the IXFP4N85X?

A: All substitute parts are RoHS3 compliant, REACH unaffected, and carry MSL 1 (unlimited) moisture sensitivity rating, matching the IXFP4N85X compliance profile. All parts are classified under ECCN EAR99 and HTSUS 8541.29.0095. No additional compliance documentation or qualification is required when substituting between these parts.

Q: How does the input capacitance vary among the substitute parts?

A: Input capacitance (Ciss) varies significantly across substitute parts. The IXFP4N85X has 247 pF @ 25V. The STP5N95K5 has 220 pF @ 100V (lowest), STP7N105K5 has 380 pF @ 100V, STP6NK90Z has 1350 pF @ 25V, and STP8NK100Z has 2180 pF @ 25V (highest). Higher input capacitance increases gate charge and switching losses. Applications with high switching frequencies or limited gate driver current should prioritize parts with lower input capacitance.