IXFK48N50Q N-Channel 500V 48A MOSFET Equivalent & Substitute Parts

Part Overview

The IXFK48N50Q is an N-Channel MOSFET manufactured by IXYS, rated for 500V drain-to-source voltage with 48A continuous drain current at 25°C. This device is part of the HiPerFET™ Q Class series and is housed in a TO-264AA through-hole package. The part is currently Active in product status with full RoHS3 compliance and unlimited moisture sensitivity rating.

Substitute parts are identified when equivalent electrical performance can be achieved within the specified parameter ranges while maintaining compatible package configurations and thermal characteristics. The IXFK48N50Q serves applications requiring high-voltage switching with moderate to high current handling, making alternative sources valuable for supply chain continuity and design flexibility.

Substiute Parts

IXFK48N50Q

IXYSIn Stock: 1366IXFK48N50Q Datasheet

Current PartRFQ

IXFK44N50P

IXYSIn Stock: 2229IXFK44N50P Datasheet

SimilarRFQ

FQL40N50F

onsemiIn Stock: 18775FQL40N50F Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the IXFK48N50Q is determined by the following critical parameters:

Voltage Rating Requirement: All substitute parts must maintain the 500V Vdss specification to ensure safe operation in the intended application circuit.

Current Handling Capability: Substitute parts must support continuous drain current ratings that meet or exceed the application requirements. The IXFK48N50Q operates at 48A; substitutes with lower current ratings (44A, 40A) are acceptable only when the application circuit does not demand the full 48A specification.

On-State Resistance (Rds On): This parameter directly affects power dissipation and thermal performance. Substitutes with higher Rds On values will generate increased heat and may require thermal management adjustments.

Package Compatibility: All identified substitutes use TO-264AA or TO-264-3 through-hole packages, ensuring mechanical and thermal interface compatibility with existing PCB designs.

Gate Charge and Threshold Voltage: These parameters influence switching speed and gate drive circuit requirements. Variations within the provided ranges indicate different switching characteristics but do not preclude substitution when the application circuit accommodates the specified gate drive voltage (10V).

Temperature Operating Range: All parts share the -55°C to 150°C operating range, ensuring thermal compatibility across the full application envelope.

Compliance Status: RoHS3 compliance and REACH unaffected status are maintained across all substitute options.

Parameter Comparison

Engineering Selection Recommendations

IXFK44N50P (IXYS): This substitute maintains the same 500V voltage rating and shares the IXYS HiPerFET™ platform. The 44A continuous drain current rating is 8% lower than the IXFK48N50Q, making this part suitable for applications where the full 48A specification is not required. The IXFK44N50P exhibits lower gate charge (98 nC versus 190 nC), enabling faster switching transitions. Higher Rds On (140 mOhm versus 100 mOhm) results in increased on-state power dissipation. This part is Active in product status with full RoHS3 compliance and higher power dissipation capability (658W). The Polar series designation indicates different internal architecture compared to the Q Class original part. Inventory availability is higher at 2130 pieces.

FQL40N50F (onsemi): This substitute provides the same 500V voltage rating within the FRFET® series. The 40A continuous drain current rating is 17% lower than the IXFK48N50Q, restricting use to lower-current applications. The FQL40N50F carries Obsolete product status, indicating discontinued manufacturing and potential long-term supply constraints. Gate charge specification (200 nC) is comparable to the original part. Rds On (110 mOhm) falls between the original and IXFK44N50P values. Power dissipation capability (460W) is lower than both the original and IXFK44N50P. Despite obsolete status, inventory availability is substantial at 18700 pieces. RoHS3 compliance is maintained. This part is suitable only for immediate replacement needs where supply from active product lines is unavailable.

Recommendation Priority: For new designs and long-term supply assurance, the IXFK44N50P is the preferred substitute when application current requirements do not exceed 44A. For existing designs currently using the IXFK48N50Q, substitution to IXFK44N50P requires verification that the application circuit operates within the 44A specification and accommodates the higher Rds On value. The FQL40N50F should be considered only when current requirements are limited to 40A or below and immediate availability is critical, with awareness of its obsolete status.

Frequently Asked Questions (FAQ)

Q: Can the IXFK44N50P directly replace the IXFK48N50Q in all applications?

A: Direct replacement is possible only when the application circuit does not require continuous drain current exceeding 44A. The IXFK44N50P is rated for 44A continuous drain current, which is 8% lower than the IXFK48N50Q. If the application operates at or near the 48A specification, substitution is not appropriate. Additionally, the higher Rds On value (140 mOhm versus 100 mOhm) will increase on-state power dissipation, requiring thermal analysis to confirm adequate heat dissipation within the application's thermal design.

Q: What is the significance of the different gate charge values between these parts?

A: Gate charge (Qg) determines the amount of charge required to switch the MOSFET from off to on state. The IXFK48N50Q requires 190 nC, while the IXFK44N50P requires only 98 nC. Lower gate charge enables faster switching transitions and reduces gate drive circuit power consumption. The FQL40N50F requires 200 nC, similar to the original part. These differences do not prevent substitution but indicate varying switching speed characteristics. The gate drive circuit must supply sufficient current at the specified 10V drive voltage to achieve the required switching performance.

Q: Are the TO-264AA and TO-264-3 packages mechanically compatible?

A: Both TO-264AA and TO-264-3 are through-hole packages with compatible pin configurations and thermal interface characteristics. The IXFK48N50Q and IXFK44N50P use TO-264AA packaging, while the FQL40N50F uses TO-264-3. These packages are mechanically interchangeable on standard PCB layouts designed for TO-264 family devices. Thermal performance may vary slightly due to internal die and lead frame differences, but PCB footprints and mounting procedures are identical.

Q: Why is the FQL40N50F marked as Obsolete?

A: Obsolete product status indicates that onsemi has discontinued manufacturing of the FQL40N50F. While inventory may be available from distributors, long-term supply cannot be assured. New designs should not incorporate obsolete parts. Existing designs using the FQL40N50F should transition to active product alternatives such as the IXFK44N50P or IXFK48N50Q to ensure supply continuity and access to manufacturer support.

Q: How do differences in Rds On affect circuit performance?

A: On-state resistance (Rds On) directly determines the voltage drop across the MOSFET when conducting current. At 24A, the IXFK48N50Q exhibits 100 mOhm Rds On, producing a 2.4V drop. The IXFK44N50P exhibits 140 mOhm Rds On at 22A, producing a 3.08V drop at equivalent current. The FQL40N50F exhibits 110 mOhm Rds On at 20A. Higher Rds On values increase power dissipation (P = I²R), requiring larger heat sinks or thermal management adjustments. Circuit efficiency and thermal performance must be recalculated when substituting parts with different Rds On specifications.

Q: Are all three parts suitable for new product designs?

A: The IXFK48N50Q and IXFK44N50P are both Active products and suitable for new designs. The FQL40N50F is Obsolete and should not be selected for new product development. Active product status ensures ongoing manufacturer support, availability of technical documentation, and supply chain reliability. New designs should prioritize the IXFK48N50Q for maximum current capability or the IXFK44N50P when current requirements are lower and cost optimization is a design objective.

Q: What compliance certifications are maintained across all substitute parts?

A: All three parts maintain RoHS3 compliance and REACH unaffected status. These certifications ensure compliance with environmental regulations in the European Union and other regulated markets. Moisture sensitivity level (MSL) is rated as 1 (Unlimited) for the IXFK48N50Q and IXFK44N50P, indicating no special moisture handling requirements during storage and assembly. The FQL40N50F lists MSL as Not Applicable. All parts share the same ECCN (EAR99) and HTSUS (8541.29.0095) classifications for export and tariff purposes.