BUL58D Equivalent & Substitute Parts

Part Overview

The BUL58D is an NPN bipolar junction transistor manufactured by STMicroelectronics, designed for high-voltage switching applications. This device operates at 450 V collector-emitter breakdown voltage with a maximum collector current of 8 A and 85 W power dissipation capability. The BUL58D is housed in a TO-220-3 through-hole package and maintains active product status with extensive inventory availability.

Substitute parts become necessary when the BUL58D reaches end-of-life status, when supply constraints occur, or when design requirements necessitate alternative electrical characteristics within compatible parameter ranges. The substitute parts listed maintain electrical and mechanical compatibility through matching voltage ratings, collector current capabilities, and package configurations.

Substiute Parts

BUL58D

STMicroelectronicsIn Stock: 34106BUL58D Datasheet

Current PartRFQ

BUT11A

STMicroelectronicsIn Stock: 2451BUT11A Datasheet

SimilarRFQ

MJE18004G

onsemiIn Stock: 1405MJE18004G Datasheet

SimilarRFQ

MJE18008G

onsemiIn Stock: 8170MJE18008G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BUL58D is determined by the following critical parameters:

Mandatory Matching Criteria:

• Transistor Type: NPN configuration
• Voltage - Collector Emitter Breakdown (Max): 450 V minimum
• Package / Case: TO-220-3 through-hole configuration
• Mounting Type: Through Hole

Compatible Variation Criteria:

• Current - Collector (Ic) (Max): Equal to or greater than 8 A
• Power - Max: Equal to or greater than 85 W
• Operating Temperature: Maximum junction temperature of 150°C or higher
• RoHS Status: ROHS3 Compliant

The substitute parts identified maintain these electrical and mechanical parameters within acceptable ranges for direct circuit board replacement. Parts with reduced current ratings (5 A) are listed as substitutes for applications where the full 8 A capability is not required, provided all other parameters remain compatible.

Parameter Comparison

Engineering Selection Recommendations

MJE18008G (onsemi) - Primary Equivalent

The MJE18008G provides the closest electrical match to the BUL58D with identical 450 V breakdown voltage and 8 A collector current rating. This part exceeds the power dissipation requirement at 125 W versus 85 W, providing additional thermal margin. The MJE18008G maintains active product status with robust inventory levels. Extended operating temperature range (-65°C to 150°C) provides broader environmental compatibility. ROHS3 compliance and REACH unaffected status align with regulatory requirements.

MJE18004G (onsemi) - Current-Limited Equivalent

The MJE18004G maintains 450 V breakdown voltage and TO-220-3 package compatibility but operates at reduced maximum collector current of 5 A. This part is suitable for applications where circuit design does not require the full 8 A capability. Active product status and extended temperature range support long-term availability. Power rating of 75 W remains adequate for reduced current operation.

BUT11A (STMicroelectronics) - Obsolete Alternative

The BUT11A shares STMicroelectronics manufacturing origin and identical 450 V voltage rating with TO-220-3 package configuration. However, this part carries obsolete product status, limiting its suitability for new designs or long-term supply assurance. Maximum collector current of 5 A and 83 W power rating restrict application scope. ROHS3 compliance remains valid.

Frequently Asked Questions (FAQ)

Q: Can MJE18008G directly replace BUL58D in existing circuit designs?

A: Yes. The MJE18008G maintains identical voltage rating (450 V), collector current capability (8 A), and TO-220-3 package configuration. Pin assignments in TO-220-3 packages are standardized (Base, Collector, Emitter), enabling direct board-level substitution without circuit modification.

Q: What is the primary difference between MJE18004G and MJE18008G?

A: The MJE18004G operates at maximum 5 A collector current with 75 W power dissipation, while MJE18008G supports 8 A with 125 W power dissipation. Both maintain 450 V breakdown voltage and TO-220-3 packaging. Selection depends on circuit current requirements.

Q: Why is BUT11A listed as a substitute despite obsolete status?

A: BUT11A is included for reference in legacy system documentation and retrofit scenarios where existing inventory exists. For new designs, active alternatives (MJE18008G or MJE18004G) are preferred due to ongoing manufacturing and supply continuity.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. BUL58D, BUT11A, MJE18004G, and MJE18008G all carry ROHS3 Compliant status, meeting environmental and regulatory requirements for lead-free manufacturing.

Q: What thermal considerations apply when substituting with MJE18008G?

A: MJE18008G provides 125 W maximum power dissipation versus BUL58D at 85 W, offering 40 W additional thermal capacity. Both devices specify 150°C maximum junction temperature. Thermal management through heatsinking remains dependent on circuit application and ambient conditions.

Q: Do substitute parts have different saturation voltage characteristics?

A: Yes. MJE18008G exhibits 700mV saturation voltage at 900mA base current and 4.5A collector current, compared to BUL58D at 2V under 1A base and 5A collector conditions. Lower saturation voltage in MJE18008G reduces power dissipation in saturated switching applications.

Q: Is the extended temperature range of MJE18008G (-65°C to 150°C) significant for substitution?

A: Extended temperature range provides operational flexibility in extreme environment applications. BUL58D specifies 150°C maximum only. For standard industrial applications operating within 0°C to 85°C, this difference is not operationally significant.