STW50NB20 Equivalent & Substitute Parts

Part Overview

The STW50NB20 is an N-Channel MOSFET manufactured by STMicroelectronics, rated for 200V drain-to-source voltage with 50A continuous drain current at 25°C. The device is housed in a TO-247-3 through-hole package and is designed for high-power switching applications with a maximum power dissipation of 280W. The STW50NB20 is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

STW50NB20

STMicroelectronicsIn Stock: 13412STW50NB20 Datasheet

Current PartRFQ

IXTH48N20T

IXYSIn Stock: 1069IXTH48N20T Datasheet

DirectRFQ

IRFP260PBF

Vishay SiliconixIn Stock: 1532IRFP260PBF Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the STW50NB20 is determined by strict alignment of the following electrical and mechanical parameters:

Critical Matching Parameters:

• FET Type: N-Channel (required)
• Drain to Source Voltage (Vdss): 200V (required)
• Package Type: TO-247-3 or compatible TO-247 variant (required)
• Mounting Type: Through Hole (required)
• Continuous Drain Current (Id): Minimum 50A at 25°C (required)
• Power Dissipation: Minimum 280W (required)

Acceptable Tolerance: Substitute parts may have drain current ratings within ±10% of the main part specification and power dissipation within ±5% of the main part specification, provided all critical parameters are met.

The two substitute parts identified—IXTH48N20T and IRFP260PBF—meet the core electrical and mechanical requirements for direct substitution in applications designed for the STW50NB20.

Parameter Comparison

Engineering Selection Recommendations

IXTH48N20T (IXYS): This substitute is an active product with RoHS3 compliance. The continuous drain current rating of 48A is within acceptable tolerance of the main part specification (96% of 50A). Power dissipation of 275W meets the minimum requirement. The TO-247 package is mechanically compatible with TO-247-3 footprints. Selection of this part is appropriate for applications where RoHS compliance is required and the 4% reduction in current capacity is acceptable within system design margins.

IRFP260PBF (Vishay Siliconix): This substitute is an active product with RoHS3 compliance and extended operating temperature range (-55°C to 150°C). The continuous drain current rating of 46A is within acceptable tolerance of the main part specification (92% of 50A). Power dissipation of 280W matches the main part exactly. Rds On specification of 55 mOhm at 28A, 10V is equivalent to the main part. The TO-247AC package is mechanically compatible with TO-247-3 footprints. Selection of this part is appropriate for applications requiring RoHS compliance and extended temperature operation.

Both substitute parts are suitable for direct replacement in applications where the STW50NB20 is specified, provided system design margins accommodate the reduced current ratings.

Frequently Asked Questions (FAQ)

Q: Can the IXTH48N20T be used as a direct replacement for the STW50NB20?

A: The IXTH48N20T is electrically and mechanically compatible with the STW50NB20. Both devices share identical Vdss (200V), package type (TO-247-3), and mounting configuration (through-hole). The continuous drain current of 48A is 96% of the main part specification. Direct substitution is valid provided system design margins accommodate the 2A reduction in current capacity.

Q: What is the difference between TO-247 and TO-247-3 packages?

A: Both designations refer to the same three-lead through-hole package configuration used for power MOSFETs. The packages are mechanically and electrically compatible. The IXTH48N20T is specified as TO-247 (IXTH variant), while the main part and IRFP260PBF are specified as TO-247-3. These are interchangeable in PCB layouts designed for TO-247-3 footprints.

Q: Why is the STW50NB20 listed as obsolete?

A: The STW50NB20 is classified as obsolete by STMicroelectronics, indicating it is no longer in active production. The IXTH48N20T and IRFP260PBF are active products from alternative manufacturers that provide equivalent electrical performance and are suitable for new designs and legacy system support.

Q: Are the substitute parts RoHS compliant?

A: Both substitute parts—IXTH48N20T and IRFP260PBF—are RoHS3 compliant. The main part STW50NB20 is RoHS non-compliant. Selection of either substitute part satisfies RoHS compliance requirements for new designs and system upgrades.

Q: How do the Rds On specifications compare?

A: The STW50NB20 specifies Rds On of 55 mOhm at 25A, 10V. The IRFP260PBF specifies Rds On of 55 mOhm at 28A, 10V, providing equivalent on-state resistance performance. The IXTH48N20T does not provide Rds On specification in the available data. For applications where on-state resistance is critical, the IRFP260PBF provides documented equivalence.

Q: What is the impact of the 4A current reduction in the IXTH48N20T?

A: The IXTH48N20T is rated for 48A continuous drain current compared to the STW50NB20 at 50A. This represents a 4% reduction in current capacity. Substitution is valid for applications where the system design includes sufficient margin to accommodate this reduction. Thermal analysis should confirm that the 275W power dissipation rating is adequate for the intended application.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes. All three devices share the TO-247-3 package configuration and through-hole mounting type. PCB layouts designed for the STW50NB20 accommodate the IXTH48N20T and IRFP260PBF without modification. Pin assignments and lead spacing are identical across all three parts.