BC547/BC548 transistor pin configuration, data sheet and application characteristics
BC547/BC548 transistor pin configuration, data sheet and application characteristics
What is a BC547 transistor?
BC547 is a common NPN bipolar transistor, so it is widely used in electronic circuits when the base pin is connected to ground, the collector and emitter will remain open circuit (reverse biased), while when the base pin is grounded When a signal is provided, the collector and emitter are turned off (forward biased).
BC547 transistor pin configuration
BC547 usually has three pins, namely collector (C), base (B) and emitter (E)
BC547 transistor characteristics:
Type: NPN bipolar transistor
Voltage:
Collector to Base Voltage (V_CBO): Typically 50V
Collector to emitter voltage (V_CEO): 45V maximum
Emitter to base voltage (V_EBO): 6V maximum
Current: The maximum collector current (I_C) is approximately 100mA.
Power: The total power consumption of this transistor is 625 mW.
Available in To-92 package
Applications: Due to its small size and low current/voltage levels, the BC547 is primarily used in small signal amplification applications. For example, it is often used as a switch or amplifier in the audio frequency range.
BC547 equivalent transistor:
BC548, BC549, BC636, BC639, 2N2222 TO - 92, 2N2222 TO - 18, 2N2369, 2N3055, 2N3904, 2N3906, 2SC5200, BC550, etc.
BC547 Introduction:
The gain value of the BC547 triode is 110~800. This value determines the amplification capability of the triode. The maximum current flowing through the collector pin is 100mA, so we cannot use this transistor to connect a load that consumes more than 100mA. To bias the transistor we have to supply current to the base pin and this current (I B ) should be limited to 5mA.
When the transistor is fully biased, it can allow a maximum current of 100mA to flow through the collector and emitter. This phase is called the saturation region, and the typical voltages allowed on the collector-emitter (V CE ) or base-emitter (V BE ) are 200 and 900 mV respectively. When the base current is removed, the transistor is completely cut off, this stage is called the cutoff region, and the base emitter voltage may be around 660 mV.
BC547 as switch:
When a transistor is used as a switch, it operates in the saturation and cutoff regions as described above. As discussed, the transistor will act as an open switch during forward bias and a closed switch during reverse bias. This biasing can be achieved by supplying the required amount of current to the base pin. As mentioned before, the bias current should be 5mA maximum. Any current above 5mA will damage the transistor; therefore, always put a resistor in series with the base pin. The value of this resistor (RB) can be calculated using the following formula.
R B = V BE / I B
Where, the V BE value of the BC547 should be 5V, the base current (I B depends on the collector current (I C )). The I B value should not exceed mA.
BC547 as amplifier:
The transistor acts as an amplifier when operating in the active region. It can amplify power, voltage and current in different configurations.
Some configurations used in amplifier circuits are
common emitter amplifier
common collector amplifier
common base amplifier
Of the above types, the common emitter type is the most popular and commonly used configuration. When used as an amplifier, the DC current gain of a transistor can be calculated using the following formula
DC current gain = collector current (I C ) / base current (I B )
BC546/BC547/BC548/BC549/BC550 Transistors: Datasheet PDF
Application areas:
Drive modules such as relay drivers, LED drivers, etc.
Amplifier modules, such as audio amplifiers, signal amplifiers, etc.
