BC549 Transistor Pinout, Uses, Equivalent

The BC549 is an NPN transistor so the collector and emitter will be on when supply small current to base. BC549 Transistor is a low current transistor so the max amount of current that could flow through the Collector pin (Ic) is 100mA, so we cannot connect loads that use above 100mA and load voltage above 30volt using this transistor. Transistor BC549 has a reasonable gain value (HEF) from 420 to 800; this value control the amplification capacity of the transistor.

When the transistor is fully biased then it can permit a max of 100mA to flow across the collector and emitter so This step is called Saturation Region. When base current is removed the transistor will be fully off, this step is called  Cut-off Region. The pin configuration of BC549.

 BC549 pinout

BC549 Transistor pin configurations

Pin No. Pin Name Description
1 Emitter Current Drains in through emitter.
2 Base Controls the current between collector and Emitter.
3 Collector Current flows out through collector.

Features of BC549:

  • Type of Package : TO-92
  • Type of Transistor: NPN
  • Maximum Collector Current(IC): 100mA
  • Max Collector & Emitter Voltage (VCE): 30V
  • Maximum Collector-Base Voltage (VCB): 30volt
  • Max Emitter-Base Voltage (VEBO): 5volt
  • Maximum Collector Dissipation (Pc):  500mW
  • Maximum Transition Frequency (fT): 150 MHz
  • Minimum & Max DC Current Gain (hFE): 110 to 800
  • Maximum Storage and Operating temperature Should Be: -65 to +150 Centigrade

 Complement of bc549

The Complement of this transistor is: BC557,BC558,BC559

BC549 equivalent

Bc549 transistor substitute, alternate and equivalent are:BC548, 2N2222, 2N3904, BC550, C945, PN100, BC337

BC549 smd

There is a list of smd alternate of To-92

  • BC546 NPN (TO-92) BC846 NPN (SOT-23)
  • BC547 NPN (TO-92) BC847 NPN (SOT-23)
  • BC548 NPN (TO-92) BC848 NPN (SOT-23)
  • BC549 NPN (TO-92) BC849 NPN(SOT-23)
  • BC556 PNP (TO-92) BC856 PNP (SOT-23)
  • BC557 PNP (TO-92) BC857 PNP (SOT-23)
  • BC558 PNP (TO-92) BC858 PNP (SOT-23)
  • BC559 PNP (TO-92) BC859 PNP (SOT-23)

Bc549 transistor working

The working of this transistor is same like NPN transistor. When a small amount of current on base is applied the emitter and collector start to flow the high level of current. It is NPN transistor that is way + current is applied on base of the transistor. When the base is connected with the ground the transistor remain in fully cut-off stage.

How We Can Use BC549:

BC549transister can also be used in many general purpose applications for example it can be used in audio preamplifier, audio amplifier and circuits, this transistor can also be used for signal amplification purposes due to its high gain characteristic, the emitter base voltage is only 5V  which BC549 can be used at the output of the microcontrollers, with the 100mA collector current NPN transistor can be used to control variety of loads in the electronic circuit like power transistors, relays, MOSFETs, LEDs,  etc.

Applications of NPN transistor

  • Darlington pair
  • Switching small loads
  • Audio Noise filters
  • LED array sequence controller
  • Small signal amplifiers

Bc549 vs BC547

BC547 and bc549 both are NPN transistor and both are alternate of each other with little difference. The difference between these two are
BC549 datasheet