BC547 Transistor Pinout, Features, Uses, Equivalent & Applications.

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In this article, the BC547 transistor pinout, features, and specifications with other information concerning the transistor are well discussed there.

BC547 transistor pinout, features, and Datasheets

BC547 Transistor Pin Description

Pin NumberPin NameDescription
1CollectorCurrent flows in yhe transistor through Collector pin.
2BaseControl the operation of the transistor with Base current.
3EmitterCurrent flow out of the transistor through Emitter pin.

Features & technical specifications of BC547 Transistor.

Transistor Package TypeTO-92
Transistor TypeNPN
Max. Collector current (Ic)100mA
Max. Collector-Emitter Voltage (Vce)45V
Max. Collector-Base Voltage (Vcb) 50V
Max. Emitter-Base Voltage (Veb)6V
Max. Collectors dissipation (Pc)500 milliwatt
Max. Transition Frequency300 MHz
Mini. & Max. DC Current Gain110 to 800
Storage and Operation Temperate range-50 to +150 Centigrade

PNP Complementary.

The PNP complement of BC547 transistor is BC557

BC547 Equivalent transistors / Replacements.

BC337, BC549, BC636, BC639, 2N2222, 2N3055, 2N3904, 2N3906, and 2N4401 all these transistors are equivalent to BC547. So therefore they can serve as a replacement on a circuit in place of each other.

Note: Before replacing the transistor in place of BC547 in a circuit, study their pin configuration. This is because some of their pinout varies with BC547 pinout.

Description & Explanation of BC547 transistor.

BC547 is a BJT NPN general-purpose transistor, used for many purposes in a circuit. It can be used as a replacement for many other transistors, switch or amplification of signals.

The transistor has a current gain value of 110 to 800 which makes it good for amplification purposes. It has a collector current of 100mA and therefore shouldn’t be used to drive a load that consumes a current greater than 100mA. The transistor can be triggered ON by applying a base current through the Base. The base current should be limited to 5mA.

At the saturation region, i.e. when the maximum current (100mA) flows through the collector and Emitter, the voltage across the collector-emitter or Base-emitter will be around 200V and 900mV respectively. The transistor turns off the transistor after turning it ON, by reducing the base current to 0V.

How to use BC547 transistor & when to use them.

The transistor is a general-purpose transistor and thus it can be used in a variety of electronic applications. It can be used as a switch ON small loads, varying low input voltage and current. It can also be used to amplify small electrical signals. BC547 also serves as a replacement for other transistors.


  • Audio Amplification circuits
  • Switching loads under 100mA
  • Transistor Darlington pair.
  • Push Pull ttransistor
  • Class B amplifier
  • Low signal Application.
  • Radio Frequency circuit

How to safely Operate the Transistor.

For good performance and longer operation of BC547, the following tips should be adhered to.

  • Do not use the transistor to drive a load that drives more than 100mA current.
  • Do not exceed the basing base voltage of the transistor. Always make use of a suitable base resistor to limit the base current.
  • The voltage of the transistor shouldn’t in any case be greater than 45V.
  • Store and operate the transistor for a temperature range of -55 to +150.

BC547 transistor used as a Switch.

The transistor can be used as a switch, in switching many electronic loads in a circuit, such as relays, and sensors.

when using BC547 as a switch, The base serves as the control for the transistor. A base current (5mA) is applied to the transistor base to turn the transistor ON and allow current to flow through the collector to the emitter. A resistor is added in series to the base of the transistor to limit the base current to 5mA. When a current greater than 5mA flows through the base, the transistor gets damaged. When the base current is removed or reduced to 0V the transistor returns to the off state. The formula below is used to calculate the value of the resistor connected in series with the base (base resistor),

Base resistor = Base emitter voltage / Base current.

The base emitter voltage should be 5V while the base current should not be greater than 5mA.

BC547 used as Amplifier.

The BC547 can serve as an amplifier when operating at the Active region. It can be used as an amplifier to amplify many signals like power, voltage, and current at different configurations.

when using a transistor as an amplifier, it can be configured using the following amplifier circuits below.

  • Common Emitter amplifier
  • Common Base amplifier
  • Common Collector amplifier

But among all the above configurations, a common emitter is commonly used.

BC547 Datasheet.

Other detailed information concerning the bc547 which wasn’t mentioned in this article can be found on the transistor datasheet.

copy and paste the link below to your web browser to download the bc547 datasheet.


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