BC547B transistor
BC546 / BC547 / BC548 / BC549 / BC550 NPN Epitaxial Silicon Transistor
BC547 is the general purpose NPN Silicon Bipolar junction transistor used to Switching and Amplification. The maximum output current capability is 100ma to drive a load across the collector to the emitter with 65v DC max. These can be used for switching to small loads like small Relays, LEDs etc, and for Audio amplifiers and signal amplifiers. Widely used in small electronics projects and other low-power consumer electronics circuits. This transistor is very popular and widely available.
Pinout of BC546 / BC547 / BC548 / BC549 / BC550 are Same (CBE)
These NPN general purpose transistors are commonly used for switching and Amplification.
Packaging: TO-92; SOT54 plastic package
FEATURES
- Low current (max. 100 mA)
- Low voltage (max. 65 V).
APPLICATIONS
- General purpose switching and amplification.
- Switching and Amplifier
- High-Voltage: BC546, VCEO = 65 V
- Low-Noise: BC549, BC550
PNP Complement of BC547 : BC556, BC557, BC558, BC559, BC560(pin CBE) | 2N3906(pin EBC)
DESCRIPTION
- NPN transistor in a TO-92; SOT54 plastic package. PNP complements: BC556 and BC557.
- (VCBO ) Collector-Base Voltage –
- BC546 : 80V
- BC547/BC550 : 50V
- BC548/549 : 30V
- Maximum Collector Current (DC) IC : 100 mA (continuous)
- ICM peak collector current: 200 mA
(VCEO ) Collector-Emitter Voltage
- BC546 : 65V
- BC547 / BC550: 45V
- BC548 / BC549: 30V
(VEBO ) Emitter-Base Voltage
- BC546 / BC547 : 6V
- BC548 / BC549 / BC550: 5V
- PC Collector Power Dissipation: 500 mW
- TJ Junction Temperature: 150 °C
- TSTG Storage Temperature Range -65 to +150 °C
BC547 transistor equivalent
BC548, BC549, BC546(Pin CBE), 2N3904 (pin EBC), 2N2222 (Pin EBC)– These transistors can be used at the place of bc547 or other NPN than these transistors also can be used but pinout configuration needs to be checked before use.
TO-92 Package
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FAQ About BC547, BC546, BC548, and BC549 Transistors
1. What are BC547, BC546, BC548, and BC549 transistors?
These are NPN bipolar junction transistors (BJTs) used in low-power switching and amplifier applications. They are commonly found in audio amplifiers, signal processing, and general-purpose electronic circuits.
2. What is the main difference between BC547, BC546, BC548, and BC549?
BC547 vs BC546 vs BC548 transistor comparison
| Transistor | Max Voltage (Vceo) | Noise Level | Application |
|---|---|---|---|
| BC546 | 65V | Low | High voltage applications |
| BC547 | 45V | Low | General-purpose use |
| BC548 | 30V | Medium | Audio and signal amplification |
| BC549 | 30V | Low (low-noise) | Low-noise audio applications |
3. What is the maximum current rating for these transistors?
All these transistors can handle a maximum collector current (Ic) of 100mA, making them suitable for low-power applications.
4. What is the pin configuration of BC547, BC546, BC548, and BC549?
For all four transistors (TO-92 package, flat side facing you):
CBE
5. What are the main applications of these transistors?
- BC546 & BC547 – Used in switching circuits, voltage amplification, and microcontroller interfacing.
- BC548 – Ideal for audio signal amplification and switching applications.
- BC549 – Preferred for low-noise amplifier circuits, such as audio preamps and microphone circuits.
6. What is the typical gain (hFE) of these transistors?
- BC546 & BC547: 110 – 800
- BC548 & BC549: 110 – 900
These values vary depending on the suffix (A, B, or C), where “C” has the highest gain.
7. Are BC547, BC546, BC548, and BC549 interchangeable?
Yes, they are interchangeable depending on the voltage and noise requirements.
- If the voltage requirement is high, use BC546 or BC547.
- If low noise is needed, BC549 is the best choice.
- BC548 is a good all-rounder for general-purpose applications.
8. What is the SMD equivalent of these transistors?
The SMD equivalent of BC547, BC546, BC548, and BC549 is BC847, BC846, BC848, and BC849 respectively (in SOT-23 package).
9. Do these transistors require a heat sink?
No, since their power dissipation is low (500mW max), they do not require a heat sink.
10. Can BC547, BC546, BC548, or BC549 be used in amplifier circuits?
Yes! They are widely used in small signal amplification, such as:
- BC549 – Best for low-noise audio amplifiers.
- BC548 – Commonly used in general audio amplifiers.
- BC547 & BC546 – Suitable for voltage amplification in circuits.
BC547, BC548 transistor Footprint dimension size
Image credit- ON semiconductor
Download Datasheet PDF
- BC546 BC547 datasheet (Motorola)- Download
- BC548CBU datasheet (Fairchild)- Download
- BC546 BC547 datasheet (Philips)- Download
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