BC550B Equivalent & Substitute Parts

Part Overview

The BC550B is an NPN bipolar junction transistor manufactured by Taiwan Semiconductor Corporation, designed for general-purpose switching and amplification applications. The device operates at a maximum collector-emitter voltage of 45 V with a maximum collector current of 100 mA and power dissipation of 500 mW. The BC550B is housed in a TO-92 through-hole package and maintains Active product status with full RoHS3 compliance. Substitute parts are identified when equivalent electrical and mechanical parameters are required due to inventory constraints, manufacturing discontinuation, or design flexibility within specified parameter ranges.

Substiute Parts

BC550B

Taiwan Semiconductor CorporationIn Stock: 5212BC550B Datasheet

Current PartRFQ

2N5232A PBFREE

Central Semiconductor CorpIn Stock: 178042N5232A PBFREE Datasheet

SimilarRFQ

BC546ABU

onsemiIn Stock: 5653BC546ABU Datasheet

SimilarRFQ

BC550CBU

onsemiIn Stock: 2948BC550CBU Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BC550B is determined by strict adherence to the following electrical and mechanical parameters:

Critical Parameters for Substitution:

• Transistor Type: NPN (must match)
• Maximum Collector Current (Ic): 100 mA (must match or exceed)
• Maximum Collector-Emitter Breakdown Voltage (Vce): 45 V minimum (must meet or exceed)
• Maximum Power Dissipation: 500 mW (must meet or exceed)
• DC Current Gain (hFE): Minimum 200 @ 2mA, 5V (must meet or exceed)
• Mounting Type: Through Hole (must match)
• Package: TO-92-3 (must match)
• RoHS3 Compliance: Required (must match)

Acceptable Parameter Variations:

• Collector-Emitter Breakdown Voltage may exceed 45 V
• Power dissipation may exceed 500 mW
• DC Current Gain may exceed minimum specification
• Transition Frequency may be specified or unspecified
• Collector Cutoff Current may vary within device specifications

All identified substitute parts meet these criteria and are classified as direct electrical and mechanical equivalents.

Parameter Comparison

Engineering Selection Recommendations

2N5232A PBFREE (Central Semiconductor Corp)

This device is suitable for direct substitution in applications where the BC550B is specified. The 2N5232A PBFREE exceeds the BC550B in collector-emitter breakdown voltage (50 V vs. 45 V) and power dissipation (625 mW vs. 500 mW). The DC current gain of 250 @ 2mA, 5V exceeds the BC550B minimum of 200. The device maintains ROHS3 compliance and operates across the identical temperature range. Moisture Sensitivity Level is rated 1 (Unlimited), indicating no moisture-related constraints during storage or handling.

BC546ABU (onsemi)

This device operates at a higher collector-emitter breakdown voltage of 65 V, providing additional voltage margin beyond the BC550B specification of 45 V. The BC546ABU includes a specified transition frequency of 300 MHz, whereas the BC550B does not specify this parameter. The DC current gain of 110 @ 2mA, 5V is lower than the BC550B minimum of 200, making this device suitable only for applications where lower current gain is acceptable. The device maintains ROHS3 compliance and identical operating temperature range.

BC550CBU (onsemi)

This device is a direct electrical equivalent to the BC550B, matching the 45 V collector-emitter breakdown voltage and 500 mW power dissipation. The BC550CBU provides a higher DC current gain of 420 @ 2mA, 5V compared to the BC550B minimum of 200. The device includes a specified transition frequency of 300 MHz. Both devices share identical package specifications (TO-92-3), RoHS3 compliance, and operating temperature range (-65°C to 150°C). The BC550CBU is manufactured by onsemi and maintains full compatibility with BC550B circuit designs.

All substitute parts are Active products with current manufacturing status and full regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can the 2N5232A PBFREE replace the BC550B in all applications?

A: The 2N5232A PBFREE meets or exceeds all critical electrical parameters of the BC550B. The higher breakdown voltage (50 V vs. 45 V) and power dissipation (625 mW vs. 500 mW) provide additional design margin. The DC current gain of 250 exceeds the BC550B minimum of 200. Substitution is valid for applications designed within BC550B specifications.

Q: Why does the BC546ABU have a lower DC current gain than the BC550B?

A: The BC546ABU is specified with a minimum DC current gain of 110 @ 2mA, 5V, which is lower than the BC550B minimum of 200. This reflects different device characterization within the BC546 product line. The BC546ABU is suitable only for applications where the lower current gain does not compromise circuit performance or where higher current gain is not required.

Q: Are all substitute parts available in the same TO-92-3 package?

A: All substitute parts identified (2N5232A PBFREE, BC546ABU, BC550CBU) are packaged in the TO-92-3 configuration, matching the BC550B package specification. Pin configuration and physical dimensions are compatible with existing PCB layouts designed for the BC550B.

Q: Do all substitute parts comply with RoHS3 requirements?

A: All substitute parts listed are RoHS3 compliant, matching the BC550B regulatory status. All devices are REACH Unaffected and classified under ECCN EAR99.

Q: What is the operating temperature range for substitute parts?

A: All substitute parts operate across the identical temperature range of -65°C to 150°C (TJ), matching the BC550B specification. This ensures thermal compatibility in applications with defined operating temperature requirements.

Q: Can the BC550CBU be used as a direct replacement for the BC550B?

A: The BC550CBU is a direct electrical and mechanical equivalent to the BC550B. Both devices share identical collector-emitter breakdown voltage (45 V), maximum collector current (100 mA), power dissipation (500 mW), and package configuration (TO-92-3). The BC550CBU provides higher DC current gain (420 vs. 200 minimum) and includes a specified transition frequency of 300 MHz. Direct substitution is valid without circuit modification.

Q: What is the difference between the BC550B and BC550CBU?

A: The BC550B and BC550CBU are both NPN transistors with identical electrical ratings (45 V, 100 mA, 500 mW). The primary differences are manufacturer (Taiwan Semiconductor vs. onsemi) and DC current gain specification (200 minimum vs. 420 minimum). The BC550CBU includes a specified transition frequency of 300 MHz. Both devices are packaged in TO-92-3 and maintain RoHS3 compliance.

Q: Are there inventory considerations when selecting substitute parts?

A: Inventory levels vary by part number. The BC550B has 5200 pieces in stock, the 2N5232A PBFREE has 17706 pieces, the BC546ABU has 5556 pieces, and the BC550CBU has 2860 pieces. Inventory availability should be evaluated based on project lead time and volume requirements.