BC547 is a 100 V, 200 mA, NPN transistors, which is a general purpose small signal transistor. The following paragraphs discuses the datasheet of BC547 transistor for a quick reference.
The following diagrams shows the pinout configuration and the symbol of the transistor BC547:
Absolute Maximum Ratings:
- Collector-Emitter Voltage (VCEO): 45V
- Collector-Base Voltage (VCBO): 50V
- Emitter-Base Voltage (VEBO): 6V
- Collector Current (IC): 100mA
- Total Device Dissipation (PD): 625mW
- Junction Temperature (Tj): -55 to +150°C
- Storage Temperature Range (Tstg): -55 to +150°C
- DC Current Gain (hFE): 110 to 800 (IC = 2mA, VCE = 5V)
- Collector-Emitter Saturation Voltage (VCE(sat)): 0.7V (IC = 10mA, IB = 0.5mA)
- Base-Emitter Saturation Voltage (VBE(sat)): 0.6V (IC = 10mA, IB = 0.5mA)
- Base-Emitter On Voltage (VBE(on)): 0.7V (IC = 10mA, VCE = 5V)
- Input Impedance (hie): 2.5kΩ (VCE = 5V, IC = 1mA, f = 1kHz)
2N2222: Another typical NPN BJT that is used as a substitute for the BC547. It has equivalent maximum voltage and current ratings and is suitable for a wide range of applications.
BC548: This transistor is identical to the BC547 but has a little greater gain and a exactly same pinout.
BC549: Like the BC547, this transistor has a little lower gain and a similar pinout.
BC546: This is a low-power NPN BJT that may be utilised in low-voltage and low-current applications as an alternative to the BC547.
2N3904: Another common NPN BJT that can be used in place of the BC547. It is widely accessible and has comparable highest voltage and current specifications.
A popular NPN bipolar junction transistor (BJT) that may be utilised in a variety of electrical circuits is the BC547. The following are a few uses for BC547:
Low-level signals can be amplified using the BC547 as an amplifier in tiny signal circuits. It is appropriate for audio pre-amplifiers, signal amplifiers, and other low-power applications due to its high current gain and low noise.
Digital circuits may also employ the BC547 as a switch. It may be utilized in a variety of digital applications, including logic gates, power supply, and other switching circuits, when employed as a switch since it has the ability to regulate the flow of current between two locations.
Circuits that produce periodic signals or waves can employ the BC547 in oscillator circuits. Because of this, it is advantageous for uses such as sine wave oscillators, waveform generators, and other oscillating circuits.
Circuits that maintain a constant output voltage from a fluctuating input value can employ the BC547 in voltage regulation circuits. It may therefore be utilised in a variety of power supply, battery chargers, and other voltage control circuits.
Many audio circuits, including microphone preamplifiers, audio mixers, and other audio amplifiers, can employ the BC547 because of its low noise and high gain.
Simple Relay Driver Application Circuit using BC547 Transistor
The following diagram shows how a single BC547 transistor can be used to construct a simple relay driver circuit:
The formula for calculating the base resistor is as given below:
R1 = (Base Voltage - BC547 base forward drop) x hFE / Relay Coil Current