BC547 NPN General Purpose Transistor

Description

BC547 is an NPN transistor.  Hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground. and will be closed (Forward biased) when a signal is provided to base pin. It has a gain value of 110 to 800, this value determines the amplification capacity of the transistor.

When this transistor is fully biased  it allows a maximum of 100mA to flow across the collector and emitter. This stage is called Saturation Region. So the typical voltage allowed across the Collector-Emitter or Base-Emitter could be 200 and 900 mV respectively. When base current is removed the transistor becomes fully off, this stage is called as the Cut-off Region and the Base Emitter voltage could be around 660 mV.

BC547 as Switch

It operates in Saturation and Cut-Off Region when used as a switch. It acts as an open switch during Forward Bias and as a Closed switch during Reverse Bias. Biasing achieved by supplying the required amount of current to the base pin. The biasing current should be a maximum of 5 mA.

BC547 as Amplifier

It acts as an Amplifier when operating in Active Region. It can amplify power, voltage and current at different configurations.

BC547 Transistor Features

• It is a Bi-Polar NPN Transistor
• Has a DC Current Gain of 800 maximum
• Its Continuous Collector current is 100mA
• Has an Emitter Base Voltage of 6V
• Maximum Base Current of 5 mA
• Lastly, available in To-92 Package

Applications

• Used in Driver Modules like Relay Driver, LED driver etc.
• Also in Amplifier modules like Audio amplifiers, signal Amplifier etc.
•  Moreover, as a Darlington pair

BC547 Equivalent Transistors

BC549, 2N2222 , 2N2369, 2N3055, 2N3904, 2N3906,

Datasheet