BUT12TU Equivalent & Substitute Parts

Part Overview

The BUT12TU is an NPN bipolar junction transistor manufactured by onsemi, rated for 400 V collector-emitter breakdown voltage and 8 A maximum collector current in a TO-220-3 through-hole package. This device is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and production continuity. The 100 W power rating and 150°C maximum junction temperature establish the thermal and electrical operating envelope for substitute selection.

Substiute Parts

BUT12TU

onsemiIn Stock: 1003BUT12TU Datasheet

Current PartRFQ

ST13007

STMicroelectronicsIn Stock: 1296ST13007 Datasheet

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ST13007D

STMicroelectronicsIn Stock: 680301ST13007D Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BUT12TU is determined by matching the following critical electrical and mechanical parameters:

• Transistor Type: NPN configuration required
• Voltage Rating: Minimum 400 V collector-emitter breakdown voltage
• Current Rating: Minimum 8 A maximum collector current
• Package: TO-220-3 through-hole mounting
• Operating Temperature: 150°C maximum junction temperature support
• Mounting Configuration: Through-hole assembly compatibility

The ST13007 and ST13007D from STMicroelectronics satisfy these core requirements. Both devices are active products with identical voltage and current ratings, matching package specifications, and equivalent thermal operating ranges. The primary distinction between substitute options relates to saturation voltage characteristics and cutoff current specifications, which affect switching performance in specific circuit topologies but do not preclude functional equivalence for general-purpose switching applications.

Parameter Comparison

Engineering Selection Recommendations

ST13007D is the primary substitute for BUT12TU applications. This device maintains active product status with STMicroelectronics, ensuring long-term availability and supply chain stability. The ST13007D demonstrates superior saturation voltage performance (2V @ 2A, 8A) compared to ST13007 (3V @ 2A, 8A), resulting in lower power dissipation during saturation-mode operation. RoHS3 compliance and REACH unaffected status align with current regulatory requirements.

ST13007 serves as an alternative substitute where ST13007D availability is constrained. Both STMicroelectronics devices provide equivalent voltage and current ratings with identical thermal operating ranges. The 80 W power rating of both substitutes is lower than the original BUT12TU specification (100 W); however, this difference does not preclude functional equivalence in applications where thermal management and circuit design accommodate the reduced power envelope.

The obsolete status of BUT12TU necessitates transition to active alternatives. Both ST13007 and ST13007D are manufactured by a major semiconductor supplier with established distribution networks, supporting design continuity and production scheduling.

Frequently Asked Questions (FAQ)

Q: Can ST13007 and ST13007D be used interchangeably with BUT12TU?

A: Both ST13007 and ST13007D satisfy the core electrical and mechanical requirements for BUT12TU substitution: 400 V breakdown voltage, 8 A collector current, TO-220-3 package, and 150°C operating temperature. Functional equivalence is established for general-purpose switching applications. Selection between ST13007 and ST13007D depends on saturation voltage performance requirements in specific circuit topologies.

Q: What is the significance of the power rating difference (100 W vs. 80 W)?

A: The BUT12TU is rated for 100 W maximum power dissipation, while ST13007 and ST13007D are rated for 80 W. This difference reflects thermal design specifications under defined operating conditions. Circuit designs must verify that actual power dissipation remains within the 80 W envelope of substitute devices. Thermal management and heat sink design may require adjustment to accommodate the lower power rating.

Q: Are there compliance or regulatory differences between BUT12TU and the substitute parts?

A: ST13007 and ST13007D are RoHS3 compliant and REACH unaffected. BUT12TU carries REACH unaffected status but does not specify RoHS compliance due to its obsolete classification. Both substitute devices meet current regulatory requirements for new designs and production.

Q: What is the difference between ST13007 and ST13007D?

A: Both devices share identical voltage, current, and package specifications. The primary differences are saturation voltage (ST13007D: 2V @ 2A, 8A; ST13007: 3V @ 2A, 8A) and collector cutoff current (ST13007D: 100µA; ST13007: 10µA). ST13007D exhibits lower saturation voltage, reducing power dissipation during saturation-mode switching. ST13007D also demonstrates higher cutoff current, which may affect leakage characteristics in specific applications.

Q: Is the TO-220-3 package identical across all three devices?

A: All three devices—BUT12TU, ST13007, and ST13007D—utilize the TO-220-3 through-hole package. Mechanical compatibility and PCB layout requirements are identical. No modifications to board design or assembly procedures are required for substitution.

Q: Why is BUT12TU classified as obsolete?

A: Obsolete classification indicates that onsemi has discontinued production and support for this device. Existing inventory may be available through authorized distributors, but long-term supply cannot be guaranteed. Transition to active alternatives such as ST13007 or ST13007D ensures design sustainability and production continuity.