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BC488 General Purpose PNP Transistor 

The BC488 is a PNP Transistor in a TO-92 package, that has a VCE of -60V and a collector current of -1000mA or -1A. It can be used as a small signal switching transistor. It also has a low base voltage of 4V.


BC488 Pinout Configuration

Pin Number

Pin Name




Controls the biasing of the transistor



Electrons emitted from the emitter into the first PN junction 



Electrons Emitted from Emitter Collected by the Collector


Features & Specifications

  • Bi-Polar PNP Transistor
  • DC Current Gain (hFE) is 400 maximum
  • Continuous Collector current (IC) is -1000mA
  • Emitter Base Voltage (VBE) is -4V
  • Base Current (IB) is -50mA maximum
  • Maximum Collector-Base Voltage |Vcb|: -60 V
  • Collector Dissipation: 0.625 W
  • Transition Frequency:150 MHz
  • Operating and Storage Junction Temperature Range -55 to +150 °C
  • Collector Capacitance 9pF
  • Available in To-92 Package


Note: Complete technical details can be found in the BC488 Datasheet given at the end of this page.


BC488 Equivalent Transistor

BC558, BC557, BC556, BC136


General Description of BC488 Transistor

BC488 can be used when you want a simple switching device for low power loads. The component is cheap and easy to work with, so it is best suited when choosing a random switching device. The BC488 transistor can also be used as a basic power amplifier and its application includes amplifying low power signals.


When this transistor is in a biased condition, then it can allow a maximum current of 1000mA across CE(Collector-Emitter) Junction, this state of the transistor is called the saturation state, and driving a load that consumes more current than 1000mA may damage the device in this condition. As you already may know a transistor is a current-controlled device so when the base current is removed the transistor becomes fully off, in this stage the transistor is working in its Cut-off Region and no current flows through the C-E junction. The BC488 Transistor has a gain of 260 to 400 this value determines the amplification capacity of the transistor, the peak current that can be flown through this transistor is 1000maA, which combined with the gain value makes this transistor a perfect choice as a driver for power transistors.


Under normal circumstances and without external influence there will be a positive voltage appearing at the base of the PNP transistor. As we all know, based on the working principle of a PNP transistor; having a positive voltage at the base puts a PNP transistor in a high resistance state. By characteristic a small amount of current needs to flow out of the base of the transistor to completely turn on the device, for this device you can see, in order to flow 1000mA of current through the collector to emitter, 50mA of current needed to flow through the base of the transistor.

BC488 Transistor Working


How to use BC488 Transistor

Transistors are current-controlled devices so to turn them on, a little current is needed. For the BC488 Transistor, this base current is less than 50mA, as BC488 is a PNP transistor that means it will be on when the base is connected to the ground, and it will be off when a positive voltage is applied to the base of the transistor. The simulated circuit below shows how this transistor behaves when the base of the basic circuit is connected to the ground and when it's connected to the power supply.

BC488 Transistor Circuit Diagram

When we turn on the transistor by connecting the base to the ground the transistor will remain on unless the voltage at the base of the transistor reaches more than the base turn-off voltage, for this transistor, it is somewhere in between 0.7 -0.9V. The base of the transistor cannot be left floating otherwise there could be false triggering, which may lead to issues in the circuit. To resolve the issue, we need to add pullup resistors as shown in the example, a 10K resistor is used to pull up the base of the transistor to VCC, and to limit the base current we have used a 300 ohms resistor.



  • Simple switching applications
  • Microphone preamplifiers
  • Lighting systems
  • Relay drivers
  • Audio Amplifiers
  • Signal Amplifiers


2D Model and Dimensions

If you are designing a PCB or Perf board with this component then the following picture from the Datasheet will be useful to know its package type and dimensions.

BC488 Transistor Dimensions

Component Datasheet

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