BC327BU Equivalent & Substitute Parts

Part Overview

The BC327BU is a PNP bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. It features a maximum collector current of 800 mA, collector-emitter breakdown voltage of 45 V, and maximum power dissipation of 625 mW in a Through Hole TO-92-3 package. The BC327BU is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity. Active alternatives with comparable electrical characteristics are available to maintain circuit functionality in new production runs or replacement applications.

Substiute Parts

BC327BU

onsemiIn Stock: 2063BC327BU Datasheet

Current PartRFQ

2N3906BU

Fairchild SemiconductorIn Stock: 502362N3906BU Datasheet

SimilarRFQ

BC32740TA

onsemiIn Stock: 4970BC32740TA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC327BU is determined by strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Transistor Type: PNP configuration required
• Package / Case: TO-92-3 Through Hole package
• Voltage - Collector Emitter Breakdown (Max): Minimum 45 V
• Current - Collector (Ic) (Max): Minimum 800 mA
• Power - Max: Minimum 625 mW
• Operating Temperature: Maximum 150°C (TJ)

Substitute parts are grouped into two categories:

1. Direct Equivalents (Identical Electrical Ratings): Parts matching all primary electrical specifications with identical or superior performance characteristics.

2. Functional Substitutes (Reduced Current Rating): Parts with lower maximum collector current but meeting voltage, power, and package requirements. These substitutes are suitable for applications where the full 800 mA current capability is not required.

Parameter Comparison

Engineering Selection Recommendations

BC32740TA (onsemi): This part is the primary substitute for the BC327BU. It maintains identical electrical specifications including 800 mA maximum collector current, 45 V collector-emitter breakdown voltage, and 625 mW power dissipation. The BC32740TA is manufactured by onsemi, the same supplier as the main part, and carries Active product status. It is ROHS3 Compliant and REACH Unaffected, meeting current regulatory requirements. The BC32740TA is supplied in Cut Tape (CT) packaging with formed leads, providing a direct functional replacement for Through Hole assembly applications. The higher DC current gain (250 @ 100mA, 1V versus 100 @ 100mA, 1V) offers improved performance characteristics.

2N3906BU (Fairchild Semiconductor): This part is a functional substitute suitable for applications where the maximum collector current requirement does not exceed 200 mA. The 2N3906BU meets the TO-92-3 package and Through Hole mounting requirements, with identical 625 mW power dissipation and 150°C maximum operating temperature. The collector-emitter breakdown voltage is 40 V, which is 5 V lower than the BC327BU specification. The 2N3906BU features a higher transition frequency of 250 MHz compared to 100 MHz for the main part. This substitute is suitable for lower-current switching applications and is available in Active product status with high inventory levels.

Frequently Asked Questions (FAQ)

Q: Can the BC32740TA directly replace the BC327BU in all applications?

A: Yes. The BC32740TA maintains identical electrical specifications for maximum collector current (800 mA), collector-emitter breakdown voltage (45 V), power dissipation (625 mW), and operating temperature range (150°C). Both parts use the TO-92-3 Through Hole package. The BC32740TA is the direct equivalent and requires no circuit modifications.

Q: What are the limitations of using the 2N3906BU as a substitute?

A: The 2N3906BU has a maximum collector current of 200 mA, compared to 800 mA for the BC327BU. This limits its use to applications where the circuit current demand does not exceed 200 mA. Additionally, the collector-emitter breakdown voltage is 40 V instead of 45 V, reducing the maximum voltage rating by 5 V. The 2N3906BU is suitable only for lower-current switching and amplification circuits.

Q: Are there package compatibility concerns when substituting these parts?

A: All three parts use the TO-92-3 Through Hole package with identical pinout and physical dimensions. Direct mechanical substitution is possible without PCB modifications. The BC32740TA is supplied with formed leads, while the BC327BU and 2N3906BU specifications do not specify lead formation; verify lead configuration with the specific supplier lot if precision lead bending is required for automated assembly.

Q: What is the difference in DC current gain between the main part and substitutes?

A: The BC327BU specifies a minimum DC current gain (hFE) of 100 @ 100mA, 1V. The BC32740TA specifies 250 @ 100mA, 1V, providing 2.5 times higher current gain. The 2N3906BU specifies 100 @ 10mA, 1V, which is measured at a lower collector current. Higher current gain in the BC32740TA may reduce base drive requirements in switching applications.

Q: Are regulatory compliance certifications equivalent across all three parts?

A: The BC327BU and BC32740TA are both ROHS3 Compliant and REACH Unaffected. The 2N3906BU compliance certifications are not specified in the provided data. Verify compliance documentation with the supplier before selecting the 2N3906BU for applications with specific regulatory requirements.

Q: Why is the BC327BU classified as obsolete?

A: The BC327BU is listed as obsolete by onsemi. The BC32740TA is the active replacement part from the same manufacturer, offering identical electrical performance with current product support and availability.

Q: Can the 2N3906BU be used in high-frequency applications?

A: The 2N3906BU has a transition frequency of 250 MHz, compared to 100 MHz for the BC327BU. This higher frequency capability makes the 2N3906BU suitable for higher-frequency switching applications, provided the 200 mA current limit is acceptable for the circuit design.