BUT12AX,127 Equivalent & Substitute Parts

Part Overview

The BUT12AX,127 is an NPN bipolar junction transistor manufactured by NXP USA Inc., designed for high-voltage switching applications. This device features a 450 V collector-emitter breakdown voltage rating with an 8 A maximum collector current and 23 W power dissipation capability in a Through Hole TO-220-3 Full Pack isolated tab package.

The BUT12AX,127 is classified as obsolete. Locating equivalent substitute parts is necessary to support ongoing maintenance, repair, and production requirements for legacy systems utilizing this component. Active alternatives with compatible electrical and mechanical specifications are available to ensure circuit continuity.

Substiute Parts

BUT12AX,127

NXP USA Inc.In Stock: 982BUT12AX,127 Datasheet

Current PartRFQ

MJF18008G

onsemiIn Stock: 1345MJF18008G Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BUT12AX,127 is determined by strict alignment of the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Transistor type must be NPN
• Maximum collector current (Ic) must be 8 A or greater
• Collector-emitter breakdown voltage (VCEO) must be 450 V or greater
• Maximum power dissipation must support the application requirements

Mechanical Compatibility Criteria:

• Mounting type must be Through Hole
• Package must be TO-220-3 Full Pack configuration
• Pin configuration must be compatible with existing PCB layouts

Compliance Requirements:

• RoHS3 compliance required
• REACH unaffected status required

The MJF18008G meets all substitution criteria and is classified as an active product, providing long-term availability and supply chain stability compared to the obsolete BUT12AX,127.

Parameter Comparison

Engineering Selection Recommendations

The MJF18008G is a direct electrical and mechanical substitute for the BUT12AX,127. Both devices share identical maximum ratings for collector current (8 A) and collector-emitter breakdown voltage (450 V), with compatible TO-220-3 Full Pack through-hole packaging.

The MJF18008G offers superior performance characteristics, including higher maximum power dissipation (45 W versus 23 W), improved DC current gain (14 versus 10 at 1 A, 5 V), and lower saturation voltage (0.7 V versus 1.5 V). These enhancements provide operational margin and improved efficiency in switching applications.

Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements. The MJF18008G is classified as an active product with established supply chain availability, eliminating obsolescence risk associated with the BUT12AX,127.

Frequently Asked Questions (FAQ)

Q: Can the MJF18008G directly replace the BUT12AX,127 in existing circuits?

A: Yes. Both devices are NPN transistors with identical maximum collector current (8 A) and collector-emitter breakdown voltage (450 V) ratings. Both use TO-220-3 Full Pack through-hole packaging with compatible pin configurations. No PCB modifications are required.

Q: What are the key differences between these parts?

A: The MJF18008G provides higher maximum power dissipation (45 W versus 23 W), improved DC current gain (14 versus 10 at 1 A, 5 V), and lower saturation voltage (0.7 V versus 1.5 V). These differences represent performance enhancements rather than incompatibilities.

Q: Are there package differences between the BUT12AX,127 and MJF18008G?

A: Both devices use TO-220-3 Full Pack through-hole packages. The BUT12AX,127 specifies an isolated tab configuration, while the MJF18008G uses standard TO-220-3 Full Pack. Pin spacing and mounting hole locations are compatible.

Q: What is the product status difference?

A: The BUT12AX,127 is obsolete, indicating discontinued manufacturing and limited availability. The MJF18008G is active, ensuring ongoing production and reliable supply chain access for future requirements.

Q: Do both parts meet current regulatory requirements?

A: Yes. Both the BUT12AX,127 and MJF18008G are ROHS3 compliant and REACH unaffected, satisfying current environmental and regulatory standards.

Q: Are there temperature rating differences?

A: Both devices support identical maximum junction temperatures of 150°C. The MJF18008G specifies an extended operating temperature range of −65°C to 150°C, providing additional low-temperature capability.