STU6N65K3 Equivalent & Substitute Parts

Part Overview

The STU6N65K3 is an N-Channel MOSFET manufactured by STMicroelectronics, rated for 650V drain-to-source voltage with 5.4A continuous drain current. This device is packaged in TO-251 (IPAK) through-hole configuration and is part of the SuperMESH3™ series. 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

STU6N65K3

STMicroelectronicsIn Stock: 17437STU6N65K3 Datasheet

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DMJ70H1D3SJ3

Diodes IncorporatedIn Stock: 845DMJ70H1D3SJ3 Datasheet

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IPS65R950C6AKMA1

Infineon TechnologiesIn Stock: 1151IPS65R950C6AKMA1 Datasheet

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IPU80R1K4P7AKMA1

Infineon TechnologiesIn Stock: 1097IPU80R1K4P7AKMA1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the STU6N65K3 is determined by the following critical parameters:

Voltage Rating Compatibility: The drain-to-source voltage (Vdss) must equal or exceed 650V to maintain circuit protection margins. Substitute parts with higher voltage ratings (700V, 800V) are acceptable as they provide enhanced voltage headroom.

Current Handling Capability: The continuous drain current (Id) at 25°C must support the application's current requirements. The STU6N65K3 specifies 5.4A; substitute parts with equal or higher current ratings ensure thermal and electrical compatibility.

On-State Resistance (Rds On): This parameter directly affects power dissipation and switching losses. Substitute parts must maintain comparable or lower Rds On values to prevent thermal runaway and ensure equivalent performance.

Gate Charge (Qg): Lower gate charge values reduce switching losses and driver circuit stress. Substitute parts with lower Qg values offer improved efficiency.

Power Dissipation Rating: The maximum power dissipation (110W for STU6N65K3) must be matched or exceeded in substitute parts to ensure thermal stability under worst-case operating conditions.

Package Compatibility: All substitute parts must use TO-251 through-hole packaging to ensure mechanical and electrical compatibility with existing PCB layouts.

Compliance and Certifications: All substitute parts must maintain ROHS3 compliance and equivalent environmental certifications.

Parameter Comparison

Engineering Selection Recommendations

DMJ70H1D3SJ3 (Diodes Incorporated): This substitute offers active product status, ensuring long-term availability and supply chain stability. The 700V Vdss rating provides 50V additional voltage margin over the STU6N65K3. The 4.6A continuous drain current is slightly lower than the main part but remains suitable for applications not requiring the full 5.4A specification. Rds On matching at 1.3 Ohm ensures equivalent power dissipation characteristics. The significantly reduced gate charge (13.9 nC versus 33 nC) improves switching efficiency. Operating temperature range extends to 155°C, providing enhanced thermal margin. This part is recommended for new designs and production continuity where active component status is required.

IPS65R950C6AKMA1 (Infineon Technologies CoolMOS™): This substitute maintains the same 650V Vdss rating as the main part, providing direct voltage compatibility. The 4.5A continuous drain current is lower than the STU6N65K3 specification. The on-state resistance of 0.95 Ohm is superior, reducing conduction losses. Gate charge is significantly lower at 15.3 nC, improving switching performance. However, this part is classified as obsolete, limiting its suitability for new production. This substitute is applicable for maintenance and repair of existing systems where component replacement is necessary.

IPU80R1K4P7AKMA1 (Infineon Technologies CoolMOS™): This substitute provides active product status and the highest voltage rating at 800V, offering maximum voltage headroom for circuit protection. The 4.0A continuous drain current is the lowest among all substitutes, requiring verification against application current demands. The 1.4 Ohm Rds On is slightly higher than the main part but remains within acceptable range. Gate charge is the lowest at 10.05 nC, providing superior switching efficiency. Operating temperature range matches the main part at 150°C. This part is recommended for applications requiring higher voltage margins and long-term component availability.

Frequently Asked Questions (FAQ)

Q: Can the DMJ70H1D3SJ3 directly replace the STU6N65K3 in existing designs?

A: The DMJ70H1D3SJ3 is mechanically and electrically compatible with the STU6N65K3 in TO-251 through-hole applications. The 700V Vdss rating exceeds the 650V requirement, and the 4.6A continuous drain current supports most applications designed for 5.4A operation. Rds On matching ensures equivalent power dissipation. Verification of application current requirements is necessary to confirm suitability.

Q: What is the primary advantage of the IPS65R950C6AKMA1 over the STU6N65K3?

A: The IPS65R950C6AKMA1 offers significantly lower on-state resistance (0.95 Ohm versus 1.3 Ohm) and reduced gate charge (15.3 nC versus 33 nC), resulting in lower conduction losses and improved switching efficiency. However, the lower continuous drain current (4.5A) and obsolete product status limit its application scope.

Q: Why does the IPU80R1K4P7AKMA1 have a lower power dissipation rating despite higher voltage rating?

A: Power dissipation is determined by the combination of on-state resistance, continuous drain current, and thermal design. The IPU80R1K4P7AKMA1 has a lower continuous drain current (4.0A) compared to the STU6N65K3 (5.4A), resulting in lower absolute power dissipation under rated conditions. The higher voltage rating (800V) does not directly increase power dissipation; it provides enhanced voltage margin for circuit protection.

Q: Are all substitute parts ROHS3 compliant?

A: Yes, all substitute parts listed (DMJ70H1D3SJ3, IPS65R950C6AKMA1, and IPU80R1K4P7AKMA1) are ROHS3 compliant, matching the environmental compliance status of the STU6N65K3.

Q: What is the difference between TO-251-3 Short Leads and TO-251-3 Stub Leads packaging?

A: Both are TO-251 through-hole packages with three leads. Short Leads and Stub Leads refer to variations in lead length and mechanical profile. These variations may affect PCB layout compatibility. Verification of PCB footprint compatibility is necessary when substituting between these package variants.

Q: Which substitute part is recommended for new production designs?

A: The DMJ70H1D3SJ3 or IPU80R1K4P7AKMA1 are recommended for new production designs due to their active product status, ensuring long-term availability and supply chain stability. Selection between these two depends on application current requirements (4.6A for DMJ70H1D3SJ3 versus 4.0A for IPU80R1K4P7AKMA1) and voltage margin preferences.

Q: Can the IPU80R1K4P7AKMA1 be used in applications requiring 5.4A continuous drain current?

A: The IPU80R1K4P7AKMA1 is rated for 4.0A continuous drain current, which is lower than the 5.4A requirement of the STU6N65K3. Use of this part in applications requiring 5.4A operation exceeds its rated specification and is not recommended without thermal analysis and derating calculations.