BC556TFR Equivalent & Substitute Parts

Part Overview

The BC556TFR is a PNP bipolar junction transistor manufactured by onsemi, rated for 65 V collector-emitter breakdown voltage and 100 mA maximum collector current. This device is packaged in a TO-92-3 through-hole configuration and is designed for small-signal switching and amplification applications. The BC556TFR is classified as obsolete, necessitating identification of equivalent substitute components for ongoing design support and procurement continuity.

Substiute Parts

BC556TFR

onsemiIn Stock: 984BC556TFR Datasheet

Current PartRFQ

BC556ATA

onsemiIn Stock: 65415BC556ATA Datasheet

DirectRFQ

BC556BTA

Fairchild SemiconductorIn Stock: 18331BC556BTA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BC556TFR are identified based on electrical and mechanical parameter equivalence. All substitute candidates must satisfy the following criteria:

Electrical Equivalence Requirements:

• Transistor Type: PNP
• Current - Collector (Ic) Max: 100 mA
• Voltage - Collector Emitter Breakdown (Max): 65 V
• Vce Saturation (Max): 650 mV @ 5mA, 100mA
• Current - Collector Cutoff (Max): 15 nA
• Power - Max: 500 mW
• Frequency - Transition: 150 MHz
• Operating Temperature (TJ): 150 °C

Mechanical Equivalence Requirements:

• Mounting Type: Through Hole
• Package / Case: TO-92-3 (TO-226AA)

DC Current Gain Consideration: The DC Current Gain (hFE) minimum specification of 110 @ 2mA, 5V establishes the baseline performance threshold. Substitute parts with equal or higher hFE values maintain functional compatibility within the specified operating conditions.

Parameter Comparison

Engineering Selection Recommendations

BC556ATA (Direct Substitute - onsemi)

The BC556ATA is a direct electrical and mechanical equivalent manufactured by onsemi under the same base product number BC556. This part maintains identical electrical specifications including collector current, breakdown voltage, saturation voltage, and DC current gain. The BC556ATA is classified as Last Time Buy, indicating continued availability with defined procurement windows. This part carries ROHS3 compliance certification, supporting environmental regulatory requirements. The BC556ATA is supplied in Cut Tape packaging, suitable for automated assembly processes.

BC556BTA (Functional Equivalent - Fairchild Semiconductor)

The BC556BTA is manufactured by Fairchild Semiconductor and satisfies all electrical and mechanical substitution criteria. This part is classified as Active, ensuring long-term availability and supply chain stability. The BC556BTA exhibits a higher DC Current Gain minimum specification of 200 @ 2mA, 5V, compared to the 110 specification of the BC556TFR. This elevated gain characteristic does not compromise compatibility and may provide improved performance margin in gain-dependent circuit topologies. The BC556BTA is supplied in Bulk packaging.

Both substitute parts are suitable for direct replacement in applications currently utilizing the BC556TFR, with no circuit modifications required.

Frequently Asked Questions (FAQ)

Q: Can the BC556ATA be used as a direct replacement for the BC556TFR?

A: Yes. The BC556ATA meets all electrical and mechanical specifications of the BC556TFR, including collector current, breakdown voltage, saturation voltage, DC current gain, power dissipation, transition frequency, and operating temperature. Both devices use identical TO-92-3 through-hole packaging. The primary difference is product status: BC556TFR is obsolete while BC556ATA is Last Time Buy.

Q: What is the significance of the higher DC Current Gain in the BC556BTA?

A: The BC556BTA specifies a minimum DC Current Gain of 200 @ 2mA, 5V, compared to 110 for the BC556TFR. This higher gain value indicates improved current amplification capability. In circuits where base current is limited, the BC556BTA provides greater collector current output for the same base drive. This characteristic does not create incompatibility; it represents an enhancement that maintains functional equivalence while potentially improving circuit performance margins.

Q: Are there packaging differences between the substitute parts?

A: All three parts use identical TO-92-3 through-hole package geometry and pin configuration. The differences lie in supplier packaging format: BC556TFR is supplied as individual units, BC556ATA in Cut Tape, and BC556BTA in Bulk. These packaging formats do not affect electrical performance or circuit-level compatibility.

Q: Which substitute part should be selected for new designs?

A: The BC556BTA is recommended for new designs due to its Active product status, ensuring long-term availability and supply chain continuity. The BC556ATA is suitable for designs requiring onsemi-specific sourcing or where Last Time Buy inventory is available. Both parts are electrically and mechanically equivalent to the BC556TFR.

Q: Are there compliance or regulatory differences between these parts?

A: The BC556ATA carries ROHS3 compliance certification. All three parts are REACH Unaffected and classified under ECCN EAR99. Compliance requirements should be evaluated against specific application and regional regulatory standards.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes. All substitute parts use the TO-92-3 through-hole package with identical pin assignments and lead geometry. No PCB modifications are required for substitution. Existing through-hole assembly processes remain unchanged.