BC550 NPN Transistor Guide: Pin Configuration, Datasheet, and Replacement Options

The BC550, a popular NPN transistor from the renowned BC547 series, stands out for its impressive versatility and reliability in various electronic applications. You can appreciate its high gain and low noise performance, making it especially suited for audio amplification. Its ability to boost weak signals while minimizing interference ensures crisp sound quality, used in audio systems where clarity is dominant. With a collector current of up to 100mA and voltage handling of 45V, the BC550 offers a robust solution for both simple and complex circuits, making it a preferred choice for you.

Catalog

BC550 Transistor Overview

The BC550 is an adaptable NPN transistor, part of the respected BC547 series, valued for its dependable performance in both commercial and classroom settings. With the capability to manage switching currents up to 100mA, it functions efficiently as an amplifier, thanks to its 500mW collector dissipation and impressive DC gain reaching 800. Gain categories include.

• BC550A: 110-220

• BC550B: 200-450

• BC550C/CG: 420-800

The wide gain range of the BC550 suits various applications, from audio amplifiers to signal processing. You can appreciate its sturdiness, which ensures consistent output across different conditions, illustrating a thoughtful design. In educational environments, this transistor helps demonstrate ultimate switching and amplification concepts, appreciated for its predictability and ease of use.

In application, selecting the right gain version of the BC550 enhances circuit efficiency. For instance, opting for a higher gain variant like the BC550C/CG can increase sensitivity in amplifier circuits. Moreover, appropriately managed heat dissipation through proper heat sinks or cooling methods can prolong the component’s life, boosting overall performance.

BC550 Pinout Configuration

BC550 Design Insights

Schematic Symbol

Physical Layout

3D Representation

Characteristics of BC550

Feature	BC550 Specification
Package Type	TO-92
Transistor Type	NPN
Max Collector Current (IC)	100 mA
Max Collector-Emitter Voltage (VCEO)	45 V
Max Collector-Base Voltage (VCBO)	50 V
Max Emitter-Base Voltage (VEBO)	5 V
Power Dissipation (PD)	500 mW
Max Transition Frequency (fT)	300 MHz
DC Current Gain (hFE)	110 - 800
Storage & Operating Temperature	-65 to +150 °C

Technical Specifications

Type	Parameter
Mount	Through Hole
Mounting Type	Through Hole
Package / Case	TO-226-3, TO-92-3 (TO-226AA)
Number of Pins	3
Supplier Device Package	TO-92-3
Weight	201 mg
Collector-Emitter Breakdown Voltage	45V
Current-Collector (Ic) (Max)	100mA
Number of Elements	1
hFE Min	110
Operating Temperature	150°C TJ
Packaging	Bulk
Part Status	Obsolete
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Termination	Through Hole
Max Operating Temperature	150°C
Min Operating Temperature	-65°C
Voltage - Rated DC	45V
Max Power Dissipation	500mW
Current Rating	100mA
Frequency	300MHz
Base Part Number	BC550
Polarity	NPN
Element Configuration	Single
Power Dissipation	500mW
Power - Max	500mW
Gain Bandwidth Product	300MHz
Transistor Type	NPN
Collector Emitter Voltage (VCEO)	45V
Max Collector Current	100mA
DC Current Gain (hFE) (Min) @ Ic, Vce	110 @ 2mA, 5V
Current - Collector Cutoff (Max)	15nA ICBO
Vce Saturation (Max) @ Ib, Ic	600mV @ 5mA, 100mA
Voltage - Collector Emitter Breakdown (Max)	45V
Frequency - Transition	300MHz
Collector Base Voltage (VCBO)	50V
Emitter Base Voltage (VEBO)	5V
REACH SVHC	No SVHC
RoHS Status	RoHS Compliant
Lead Free	Lead Free

Alternatives to the BC550 Transistor

Part Number	Description	Manufacturer
MPQ6530	Small Signal Bipolar Transistor, 0.6A (IC), 40V (VBR), 1-Element, NPN, Silicon, TO-92	Motorola Semiconductor Products
ZTX557SM	Small Signal Bipolar Transistor, 0.5A (IC), 300V (VBR), 1-Element, PNP, Silicon, TO-92 COMPATIBLE, E-LINE PACKAGE-3	Zetex / Diodes Inc
BC550-TR	Transistor 100 mA, 45 V, NPN, Si, SMALL SIGNAL TRANSISTOR, TO-92, BIP General Purpose Small Signal	NXP Semiconductors
FXT5550	Small Signal Bipolar Transistor, 1A (IC), 60V (VBR), 1-Element, NPN, Silicon, PLASTIC, E-LINE PACKAGE-3	Zetex / Diodes Inc
ZTX555M	Small Signal Bipolar Transistor, 1A (IC), 100V (VBR), 1-Element, NPN, Silicon, TO-92 COMPATIBLE, E-LINE PACKAGE-3	Diodes Incorporated
UTZX549ASMT C	Small Signal Bipolar Transistor, 1A (IC), 30V (VBR), 1-Element, PNP, Silicon, TO-92 COMPATIBLE, E-LINE PACKAGE-3	Diodes Incorporated
ZTX450F	Small Signal Bipolar Transistor, 1A (IC), 60V (VBR), 1-Element, NPN, Silicon, PLASTIC, E-LINE PACKAGE-3	Diodes Incorporated
UTZX549ASTOA	Small Signal Bipolar Transistor, 1A (IC), 30V (VBR), 1-Element, PNP, Silicon, TO-92 COMPATIBLE, E-LINE PACKAGE-3	Diodes Incorporated
ZTX1090T8	Small Signal Bipolar Transistor, 1A (IC), 30V (VBR), 1-Element, NPN, Silicon, TO-92 STYLE, E-LINE PACKAGE-3	Diodes Incorporated
UTZX4499MTC	Small Signal Bipolar Transistor, 1A (IC), 30V (VBR), 1-Element, NPN, Silicon, TO-92 COMPATIBLE, E-LINE PACKAGE-3	Diodes Incorporated

Equivalents Transistor Choices for BC550

• BC337

• BC546

• BC547

• BC548

• BC549

• BC639

• 2N2222

• 2N3904

• C945

• 2SC1815

• 2SC3198

PNP Complementary Component

• BC560

Comparison of BC550 and BC547

BC550 and BC547 belong to the NPN transistor family, a staple in numerous electronic circuits. Despite sharing many attributes, they differ notably in their voltage capacities, influencing their roles in various applications.

• BC550: Exhibits a higher voltage capacity and excels in reducing noise, making it particularly suited for audio systems where clarity of sound is highly valued.

• BC547: Alongside BC548, it features a higher breakdown voltage, making it versatile for general-purpose use.

In the world of audio equipment, the BC550’s proficiency in curbing noise substantially boosts sound quality—a necessity derived from stringent audio design standards. This characteristic makes it a preferred choice for high-fidelity systems where reducing signal interference is insistent. For projects demanding greater voltage resilience, such as certain switch-mode power supplies, the BC547 provides a dependable option. This is mostly beneficial in scenarios where withstanding voltage spikes are a priority.

Uses of the BC550

The BC550 is a transistor with remarkable versatility, often celebrated for its broad applicability across electronic circuits. Known for its low noise and notable gain, it plays notable roles in analog and digital environments, making it a cherished option for small signal amplification and switching.

• Darlington Pairs: The BC550 excels in Darlington configurations, effectively pairing transistors to achieve high current gain. Often employed to amplify weak signals, it enhances sensitivity exquisitely in audio equipment.

• Audio Amplification: With an affinity for audio amplification, this transistor is ideal, especially where noise reduction is active. You might embrace the BC550 to augment input signals in preamplifiers for pristine clarity.

• Signal Amplification: Its substantial gain supports signal amplification across various circuit applications. It fortifies signals in radio frequency (RF) circuits with minimal distortion impact.

• Microcontroller Outputs: When interfacing microcontrollers with external devices, the BC550 amplifies control signals, adeptly driving loads that surpass the microcontroller’s current capacity, proving valuable in embedded systems.

• Switching Below 100mA: Serving efficiently in switching circuits under 100mA, it adeptly manages minor electronic components. You can leverage this for low-power device control without stressing the transistor.

• Relays and LEDs: In relay circuits, the BC550 interfaces between low and high-power outputs, reliably activating relay coils. It also serves in LED circuits for precise on/off control.

• PWM Applications: Pulse Width Modulation (PWM) applications benefit from the BC550’s rapid switching ability. It modulates signal width in motor speed control, enhancing system responsiveness.

• LED Dimmers: The BC550 enables adjustable brightness control in LED dimming circuits by modulating current flow, ensuring efficient energy use.

• H-Bridge Circuits: Supporting motor control in H-Bridge configurations, it allows directional changes and speed modulation. You can often employ this transistor to execute precise motion commands.

• Current Mirrors: The BC550 is active in current mirror circuits, offering consistent current flow, a cornerstone in analog integrated circuit design for stable performance.

• Impedance Buffering: Used in impedance buffering, it shields sensitive circuit stages from load variations, preserving signal integrity and high-quality analog signal processing.

• Oscillators and Comparators: In oscillators and comparators, the BC550's stability and reliability are prized, ensuring accurate timing and waveform generation, basic in digital clocks and waveform generators.

BC550 Package

Manufacturer Information

ON Semiconductor excels in crafting energy-efficient solutions, reaching various sectors including automotive and consumer electronics. Their pursuit of technological advancement is showcased through the creation of innovative components that align with modern infrastructures. This focus not only enhances device performance but also plays a role in fostering global energy conservation efforts.

A dependable supply chain underpins ON Semiconductor's operational success. Through advanced logistics and strategic partnerships, they ensure timely delivery and uphold high-quality standards. Such a careful approach aids in reducing disruptions and maintaining a seamless flow of components to satisfy market needs. Industry leaders frequently draw inspiration from these strategies to refine their logistics and sustain their market standing.

Their global commitment to quality is mirrored by inconsistent standards across all facilities. These standards not only ensure uniform product quality but also build confidence with industry partners. Delivering excellence on a worldwide scale demands an exact understanding of local regulations and customer expectations, nurturing trust, and fostering enduring partnerships.

Datasheet PDF

BC550B Datasheets:

BC546-50 Datasheet.pdf

Frequently Asked Questions [FAQ]

1. What is BC550?

The BC550 is appreciated for its flexibility as an NPN transistor, frequently utilized in scenarios with loads below 100mA. Its dual roles, enhancing signals as an amplifier and controlling operations as a switch, serve various circuit applications. You value its sustained stability and reliability in low-power contexts, often weighing the decision between its roles based on specific circuit needs.

2. How to safely long-run BC550 in a circuit?

Ensure that the current stays under 100mA while the voltage is kept below 45V DC. A suitable base resistor can protect against unwanted current surges. Storing the component between -65°C and 150°C is advisable. From hands-on experience, routinely monitoring these conditions during design and testing can avoid potential issues.

3. Why it is called a bipolar junction transistor?

Bipolar junction transistors (BJTs) use both holes and electrons as charge carriers, setting them apart from unipolar field-effect transistors. This distinctive charge carrier interaction enhances gain and improves switching speed, beneficial for high-frequency applications. The interplay of these carriers is instrumental in achieving targeted electronic results.

4. Can BC550 be replaced by BC547?

Replacing the BC550 with the BC547 is doable if their hFE values are considered. The BC550 typically provides a higher hFE, indicating a greater gain. You can adjust for this to ensure that substitution doesn't negatively impact circuit function. Thoughtful evaluation of these factors is used to uphold circuit performance.