BC547ATA Equivalent & Substitute Parts

Part Overview

The BC547ATA is a small-signal NPN bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. It features a maximum collector current of 100 mA, collector-emitter breakdown voltage of 45 V, and a transition frequency of 300 MHz. The device is housed in a TO-92-3 through-hole package with a maximum power dissipation of 500 mW.

The BC547ATA is classified as obsolete. Locating equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications utilizing this transistor.

Substiute Parts

BC547ATA

onsemiIn Stock: 8781BC547ATA Datasheet

Current PartRFQ

BC547BTA

Fairchild SemiconductorIn Stock: 1332BC547BTA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC547ATA is determined by strict equivalence across the following critical electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Transistor type must be NPN
• Maximum collector current must be 100 mA or greater
• Collector-emitter breakdown voltage must be 45 V or greater
• Vce saturation must not exceed 600 mV at specified bias conditions
• Collector cutoff current must not exceed 15 nA
• Transition frequency must be 300 MHz or greater
• Maximum power dissipation must be 500 mW or greater

Mechanical Equivalence Criteria:

• Package type must be TO-92-3 (TO-226-3)
• Mounting configuration must be through-hole

The BC547BTA meets all specified electrical and mechanical parameters and qualifies as a direct substitute for the BC547ATA.

Parameter Comparison

Engineering Selection Recommendations

The BC547BTA is a qualified substitute for the BC547ATA based on the following factors:

Electrical Compatibility: The BC547BTA meets or exceeds all critical electrical parameters specified for the BC547ATA. The DC current gain (hFE) of 200 at 2 mA, 5 V exceeds the minimum requirement of 110, and the maximum power dissipation of 625 mW exceeds the 500 mW specification. These performance margins ensure functional compatibility in existing circuit designs.

Mechanical Compatibility: Both devices utilize identical TO-92-3 through-hole packaging, enabling direct physical substitution without PCB layout modifications.

Product Status and Supply: The BC547BTA is classified as active product status, ensuring ongoing availability and supply chain continuity. The BC547ATA is obsolete, making the BC547BTA the appropriate alternative for new procurement and production support.

Compliance and Certifications: Both parts carry equivalent regulatory classifications (ECCN: EAR99, HTSUS: 8541.21.0075). The BC547BTA maintains the same electrical safety and environmental compliance framework as the BC547ATA.

Frequently Asked Questions (FAQ)

Q: Can the BC547BTA be used as a direct replacement for the BC547ATA in existing designs?

A: Yes. The BC547BTA is electrically and mechanically equivalent to the BC547ATA. All critical parameters—collector current, breakdown voltage, saturation voltage, cutoff current, and transition frequency—are identical or exceed the BC547ATA specifications. The TO-92-3 package is identical, permitting direct substitution without circuit redesign.

Q: What are the differences between the BC547ATA and BC547BTA?

A: The primary differences are manufacturer (onsemi versus Fairchild Semiconductor) and product status (obsolete versus active). The BC547BTA provides higher DC current gain (200 versus 110 minimum), greater power dissipation capability (625 mW versus 500 mW), and an extended operating temperature range (−55°C to 150°C versus 150°C maximum). These differences represent performance enhancements that do not compromise compatibility.

Q: Are there any package or pinout differences between these devices?

A: No. Both the BC547ATA and BC547BTA use the TO-92-3 (TO-226-3) through-hole package with identical pinout and lead configuration. Physical substitution requires no modifications to PCB layouts or component mounting procedures.

Q: What is the significance of the higher DC current gain in the BC547BTA?

A: The BC547BTA minimum DC current gain of 200 at 2 mA, 5 V exceeds the BC547ATA specification of 110. This higher gain provides improved circuit performance and may reduce base drive requirements in switching applications. The higher gain is compatible with designs specified for the BC547ATA and does not introduce functional incompatibility.

Q: Why is the BC547ATA listed as obsolete?

A: The BC547ATA is classified as obsolete by the manufacturer. The BC547BTA, manufactured by Fairchild Semiconductor, is the active equivalent product. For new designs and ongoing production, the BC547BTA is the recommended selection to ensure long-term supply availability.

Q: Are both devices RoHS compliant?

A: The BC547ATA is RoHS3 compliant. Compliance information for the BC547BTA is not provided in the available technical data. Verification of RoHS compliance status for the BC547BTA should be obtained from the manufacturer or authorized distributor if RoHS certification is a design requirement.