BU406 Equivalent & Substitute Parts

Part Overview

The BU406 is an NPN bipolar junction transistor (BJT) manufactured by onsemi, designed for high-voltage switching and amplification applications. The device is rated for 200 V collector-emitter breakdown voltage with a maximum collector current of 7 A and 60 W power dissipation in a Through Hole TO-220-3 package. The BU406 is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. The BU406G serves as the direct active substitute, maintaining identical electrical specifications while offering current manufacturing availability.

Substiute Parts

BU406

onsemiIn Stock: 105416BU406 Datasheet

Current PartRFQ

BU406G

onsemiIn Stock: 1477BU406G Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BU406 with the BU406G is based on strict electrical and mechanical parameter equivalence. Both devices share identical ratings across all critical performance specifications: 200 V maximum collector-emitter breakdown voltage, 7 A maximum collector current, 60 W maximum power dissipation, 10 MHz transition frequency, and 1 V saturation voltage at specified bias conditions. Both transistors are packaged in the TO-220-3 Through Hole configuration, ensuring mechanical and thermal compatibility in existing PCB layouts. The substitution is valid based on matching transistor type (NPN), voltage rating, current rating, power rating, frequency response, saturation characteristics, and package form factor. Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for equivalent component selection.

Parameter Comparison

Engineering Selection Recommendations

The BU406G is the direct equivalent substitute for the obsolete BU406. Selection of BU406G is appropriate for all applications previously designed with BU406 components. The BU406G maintains active product status with current manufacturing availability, eliminating supply chain risk associated with obsolete part sourcing. Both devices are manufactured by onsemi and carry identical electrical specifications, ensuring functional compatibility without circuit redesign. The BU406G operates across an extended temperature range of −65°C to 150°C, compared to the BU406 operating temperature specification of 150°C maximum, providing improved thermal margin in applications subject to low-temperature environments. Both parts satisfy ROHS3 compliance and REACH regulatory requirements. The TO-220-3 package form factor is identical between both devices, permitting direct PCB layout compatibility. For new designs and production transitions from obsolete BU406 inventory, BU406G is the specified equivalent part.

Frequently Asked Questions (FAQ)

Q: Can BU406G directly replace BU406 in existing circuit designs?

A: Yes. The BU406G is electrically and mechanically equivalent to the BU406 across all specified parameters. Both devices share identical voltage ratings (200 V), current ratings (7 A), power ratings (60 W), saturation characteristics, and TO-220-3 package configuration. Direct substitution is valid without circuit modification.

Q: What is the primary difference between BU406 and BU406G?

A: The BU406 is classified as obsolete, while BU406G maintains active product status with current manufacturing availability. The BU406G also specifies an extended operating temperature range of −65°C to 150°C compared to the BU406 maximum operating temperature of 150°C. All electrical performance specifications are identical.

Q: Are there any package or pinout differences between BU406 and BU406G?

A: No. Both devices are packaged in the TO-220-3 Through Hole configuration with identical pinout and mechanical dimensions. PCB layouts designed for BU406 require no modification for BU406G installation.

Q: Do both parts meet current regulatory compliance standards?

A: Yes. Both BU406 and BU406G are ROHS3 compliant and REACH unaffected, satisfying current regulatory requirements for electronic component manufacturing and distribution.

Q: What is the inventory status of these parts?

A: BU406 inventory is limited to existing stock (105,400 pcs reported). BU406G is actively manufactured with current availability (1,427 pcs reported in active inventory). For new production requirements, BU406G is the recommended source.

Q: Are there any thermal or performance advantages to using BU406G over BU406?

A: The BU406G specifies an extended operating temperature range extending to −65°C, providing improved performance margin in low-temperature applications. All other electrical and thermal specifications are identical between the two devices.