BC179 Transistor Pinout, Features, Applications, Equivalent and Other Useful details

This article contains all the important information of BC179 component such as BC179 transistor pinout, features, applications, equivalent and other useful details about this device.




Absolute Maximum Ratings:

  • Package Type: TO-18
  • Transistor Type: PNP
  • Max Collector Current(IC): -100mA or -200mA (See text) *
  • Max Collector-Emitter Voltage (VCEO): -20V
  • Max Emitter-Base Voltage (VEBO): -5V
  • Max Collector Dissipation (PC): 300 Milliwatt
  • Max Transition Frequency (fT): 130 MHz or 200 MHz (See text)*
  • Minimum & Maximum DC Current Gain (hFE): 180 to 800
  • Max Storage & Operating temperature: -65 to +175 Centigrade


NPN Complementary:

NPN Complementary of BC178 is BC109


Replacement and Equivalent:

BC177B, BC177A, BC477, BC292, BC291, BCY77, BCY71, BC266, 2SA1218. TO-92 package replacements are: BD559, BD558, BD560, BC557, BC556, and BC560.


BC179 Transistor Explained / Description:

BC179 is a transistor of BC17x series which is a series of TO-18 package PNP transistors. The series also contains other transistors such as BC177 and BC178.

The pin layout of BC179 is as follows. The nearest pin of the tag is the pin1 of the transistor which is Emitter, the middle pin or the pin that is near to the pin1 is the pin2 which is the Base and the last one is pin2 which is Collector.

Understanding the absolute maximum ratings of the transistor the maximum collector-emitter voltage (VCEO) is -20V, regarding to the maximum collector current Some manufacturers make it in 100mA and some in 200mA so it is important to check the datasheet of the manufacturer before purchasing*. Moreover, the max emitter-base voltage is -5V and the collector dissipation is 300mW.

The transistor is designed to be used in audio amplifier stages but due to its good electrical characteristics, it can also be used for wide variety of other purposes such as due to its good DC current gain and low noise capabilities it can also be used as a preamplifier or any for any kind of low level signal amplification. Moreover, the transition frequency of 200MHz also makes it ideal to use in RF circuits (Some manufacturers also make it in 100MHz so it is suggested to check the datasheet of the manufacturer before purchasing)*. The detailed list of its applications can be found under the “Applications” heading below.


Where We Can Use it & How to Use:

As already discussed above BC179 is designed to be used in audio amplifier stages but it can also be used in wide variety of other applications such as switching, audio preamplification, signal amplification, etc. It is a BJT transistor so the using procedure same as we use any other BJT transistor.



Audio Amp Stages

Signal Amplification

Audio amplifier circuits



Output of Microcontrollers for Driving Different Loads

Drive Loads Under 100mA


Safe Operating Guidelines:

Here are some guidelines for using the transistor safely

  • Do not use the transistor to its absolute maximum ratings and stay at least 20% below from these ratings.
  • So the maximum collector current of the transistor is -200mA but by staying 20% below we will only use -160mA. If the transistor’s gain is 100mA we will use under 80mA.
  • The maximum collector-emitter voltage is -20V so following the 20% below rule we will use not more than 16V.
  • The minimum and maximum temperature ratings are -65 °C to +175 °C. So make sure these limits should be maintained.



To download the datasheet just copy and paste the below link in your browser.


You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *