BC107B Equivalent & Substitute Parts

Part Overview

The BC107B is an NPN bipolar junction transistor manufactured by STMicroelectronics, housed in a TO-18 metal can package. This device is rated for 45 V collector-emitter breakdown voltage and 100 mA maximum collector current, with a maximum power dissipation of 300 mW. The BC107B is classified as obsolete, making identification of suitable substitute components necessary for ongoing design support and production continuity. Equivalent parts must maintain electrical compatibility across critical parameters including voltage ratings, current handling, and thermal characteristics while accommodating the through-hole TO-18 mounting standard.

Substiute Parts

BC107B

STMicroelectronicsIn Stock: 4145BC107B Datasheet

Current PartRFQ

BCY59-VII PBFREE

Central Semiconductor CorpIn Stock: 737BCY59-VII PBFREE Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC107B is determined by strict equivalence across the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Transistor type must be NPN
• Collector-emitter breakdown voltage must equal or exceed 45 V
• Maximum collector current must equal or exceed 100 mA
• Vce saturation characteristics must be compatible with circuit bias conditions
• DC current gain (hFE) must support intended amplification requirements
• Collector cutoff current must remain within acceptable leakage specifications

Mechanical Compatibility Criteria:

• Package must be TO-18 metal can (TO-206AA, TO-18-3)
• Through-hole mounting configuration required
• Physical dimensions must match existing PCB footprints

Regulatory Compliance:

• RoHS3 compliance required
• REACH unaffected status required

The BCY59-VII PBFREE meets all electrical and mechanical substitution criteria while maintaining regulatory compliance. This part is classified as active product status, ensuring continued availability and supply chain stability.

Parameter Comparison

Engineering Selection Recommendations

The BCY59-VII PBFREE is a direct substitute for the obsolete BC107B across all critical electrical and mechanical parameters. Selection of this substitute is supported by the following factors:

Product Status Consideration: The BC107B is classified as obsolete, creating supply chain risk. The BCY59-VII PBFREE is classified as active product, ensuring long-term availability and manufacturing continuity.

Regulatory Compliance: Both components maintain ROHS3 compliance and REACH unaffected status, satisfying current environmental and regulatory requirements.

Electrical Performance: The BCY59-VII PBFREE meets or exceeds all critical electrical specifications. The higher power rating (1 W versus 300 mW) and extended operating temperature range (−65°C to 200°C versus 175°C maximum) provide enhanced thermal margin and environmental flexibility. The lower collector cutoff current (10 nA versus 15 nA) indicates superior leakage characteristics.

Design Consideration: The BC107B exhibits higher minimum DC current gain (200 versus 120). Circuits designed with the BC107B may require base current adjustment when substituting the BCY59-VII PBFREE to achieve equivalent collector current levels. This adjustment is straightforward in resistive bias networks and does not affect circuit topology or functionality.

Package Compatibility: Both components utilize identical TO-18 metal can packaging with through-hole mounting, ensuring direct PCB footprint compatibility without layout modification.

Frequently Asked Questions (FAQ)

Q: Can the BCY59-VII PBFREE directly replace the BC107B without circuit modification?

A: The BCY59-VII PBFREE is mechanically and electrically compatible with the BC107B. However, the lower DC current gain (120 versus 200) requires adjustment of base bias resistors to maintain equivalent collector current levels. The circuit topology remains unchanged; only resistor values require recalculation based on the new hFE specification.

Q: What is the significance of the higher Vce saturation voltage in the BCY59-VII PBFREE?

A: The BCY59-VII PBFREE exhibits 700 mV saturation voltage compared to 600 mV for the BC107B. This 100 mV difference is negligible in most switching applications and linear amplifier circuits. Applications requiring extremely low saturation voltage should evaluate circuit performance with the substitute part.

Q: Why does the BCY59-VII PBFREE have a higher power rating?

A: The BCY59-VII PBFREE is rated for 1 W maximum power dissipation compared to 300 mW for the BC107B. This higher rating reflects superior thermal design and packaging characteristics of the Central Semiconductor device. The higher rating provides additional thermal margin but does not change the electrical operating point of the circuit.

Q: Are there any temperature-related considerations when substituting these parts?

A: The BCY59-VII PBFREE operates across a wider temperature range (−65°C to 200°C) compared to the BC107B (maximum 175°C). This extended range accommodates broader environmental conditions. Both parts maintain ROHS3 compliance across their respective operating ranges.

Q: Is the TO-18 package identical between both parts?

A: Both the BC107B and BCY59-VII PBFREE utilize the TO-206AA, TO-18-3 metal can package. Physical dimensions, lead spacing, and through-hole mounting configuration are identical, enabling direct PCB footprint compatibility without layout modification.

Q: What is the inventory status of these parts?

A: The BC107B has 4038 pieces in stock but is classified as obsolete. The BCY59-VII PBFREE has 724 pieces in stock and is classified as active product, ensuring continued availability for future production requirements.

Q: Do both parts meet current environmental compliance standards?

A: Both the BC107B and BCY59-VII PBFREE are ROHS3 compliant and REACH unaffected. Both parts satisfy current environmental and regulatory requirements for electronic component manufacturing and distribution.