BUL138FP Equivalent & Substitute Parts

Part Overview

The BUL138FP is an NPN bipolar junction transistor manufactured by STMicroelectronics, rated for 400 V collector-emitter breakdown voltage and 5 A maximum collector current in a TO-220FP through-hole package. This device is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement continuity. Substitute parts must maintain electrical compatibility across voltage, current, and thermal specifications while accommodating the through-hole TO-220FP package format.

Substiute Parts

BUL138FP

STMicroelectronicsIn Stock: 795BUL138FP Datasheet

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ST13007DFP

STMicroelectronicsIn Stock: 2308ST13007DFP Datasheet

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MJF18004G

onsemiIn Stock: 2190MJF18004G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BUL138FP is determined by the following criteria:

Primary Compatibility Requirements:

• Transistor type must be NPN
• Collector-emitter breakdown voltage must be greater than or equal to 400 V
• Maximum collector current must be greater than or equal to 5 A
• Maximum power dissipation must be greater than or equal to 33 W
• Package must be TO-220-3 Full Pack (TO-220FP)
• Mounting type must be through-hole

Secondary Compatibility Considerations:

• Vce saturation characteristics
• DC current gain (hFE) specifications
• Operating temperature range
• RoHS3 compliance status

The identified substitute parts meet or exceed the primary electrical and mechanical requirements of the BUL138FP, enabling direct functional replacement in circuit applications.

Parameter Comparison

Engineering Selection Recommendations

ST13007DFP (STMicroelectronics): This substitute maintains identical voltage and thermal specifications to the BUL138FP while providing enhanced current handling capability at 8 A maximum collector current. Both devices share obsolete product status and ROHS3 compliance. The ST13007DFP exhibits higher Vce saturation voltage (2V at rated current) compared to the BUL138FP (700mV), which may impact power dissipation in saturation-mode applications. Selection is appropriate for applications where increased current capacity is beneficial and saturation voltage elevation is acceptable.

MJF18004G (onsemi): This substitute provides active product status, ensuring long-term availability and supply chain continuity. The MJF18004G exceeds the BUL138FP in collector-emitter breakdown voltage (450 V versus 400 V) and offers an extended operating temperature range (−65°C to 150°C). Current and power ratings are equivalent to the BUL138FP at 5 A and 35 W respectively. The MJF18004G includes transition frequency specification (13 MHz) and operates within the SWITCHMODE™ series. This device is recommended for new designs and applications requiring long-term component availability.

Both substitute parts maintain TO-220FP package compatibility and through-hole mounting configuration, enabling direct mechanical and electrical integration into existing circuit layouts.

Frequently Asked Questions (FAQ)

Q: Can the ST13007DFP directly replace the BUL138FP in all applications?

A: The ST13007DFP meets the primary electrical and mechanical requirements for substitution. However, the elevated Vce saturation voltage (2V at 2A, 8A versus 700mV at 1A, 5A) results in increased power dissipation during saturation operation. Circuit designs sensitive to saturation voltage characteristics require thermal and performance analysis before implementation.

Q: Why is the MJF18004G recommended over the ST13007DFP?

A: The MJF18004G maintains active product status, providing assured long-term availability and supply chain support. The ST13007DFP is classified as obsolete, presenting potential future procurement challenges. For new designs and applications requiring extended component lifecycle, the MJF18004G is the preferred selection.

Q: Are all substitute parts available in the same TO-220FP package?

A: Yes. The BUL138FP, ST13007DFP, and MJF18004G are all packaged in TO-220-3 Full Pack (TO-220FP) configuration with through-hole mounting. Mechanical compatibility is maintained across all three devices, enabling direct board-level substitution without layout modification.

Q: What is the significance of the MJF18004G's 450 V breakdown voltage rating compared to the BUL138FP's 400 V?

A: The higher breakdown voltage rating (450 V) provides additional voltage margin and enhanced overvoltage protection. This characteristic is beneficial in applications subject to transient voltage spikes or marginal supply regulation. The 50 V additional rating does not compromise functionality in circuits designed for 400 V operation.

Q: Does the MJF18004G's extended temperature range (−65°C to 150°C) provide operational advantages?

A: The extended lower temperature limit (−65°C versus unspecified minimum for BUL138FP) enables operation in cold-environment applications. The upper temperature limit remains equivalent at 150°C. Selection based on temperature range is application-dependent and should be evaluated against specific operating environment requirements.

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

A: All three devices maintain ROHS3 compliance and REACH unaffected status. No regulatory or compliance barriers exist to substitution. The MJF18004G and ST13007DFP are both classified under ECCN EAR99 with identical HTSUS coding (8541.29.0095), matching the BUL138FP classification.