When we turn on the transistor by connecting the base to the ground(in our case we have used a 0V probe in protius), 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 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 5V of the power supply. For the BC556 Transistor, this current is less than 2mA, as BC556 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.
Transistors are current-controlled devices so to turn them on/off a little current is needed. 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 the Base Emitter voltage could be around 660 mV.īC556 Transistor has a gain of 125 to 450 which determines the amplification capacity of the transistor, the peak current that can be flown through this transistor is 200maA, which combines with the gain value makes this transistor a perfect choice for a preamplifier for audio amplifier.
When this transistor is in biased condition, then it can allow a maximum current of 100mA across CE(Collector-Emitter) Junction, this state of the transistor is called the saturation state, and driving a load that consumes more current than 100mA may damage the device in this condition. This transistor has a collector-emitter voltage of -65V and a collector base voltage of -80V. The maximum collector current of this transistor is rated at -100mA with a peak current of -200mA, this transistor has an emitter-base voltage of -5V. This transistor comes with many different versions, if you are using this transistor as an amplifier make sure you check the gain of the transistor from the datasheet that can be found down below, because of different versions the gain value differs which can completely ruin your calculations.
The BC556 is a PNP Transistor, hence we need to provide zero volts to the base of the transistor to turn it on. Where an NPN transistor is on when a positive or high signal is applied. In a PNP transistor holes are the majority charge carrier that means the holes are emitted by the collector and collected by the emitter, the main difference between the NPN and PNP transistor is the flow of electrons runs from collector to emitter but in a PNP transistor the electrons run from emitter to collector, as a result, a PNP transistor turns on when there is a low or 0V on the base of the transistor. You can check out the BC556 Datasheet, given at the bottom of the page.īC558, S8550, A1015, BC557, 2N3906, 2N4403, BC857, 2N2907, 2N5401Ī PNP transistor is made up of a doped N-Type material that is sanduzied in between two P-Type materials. Note: The above specs can vary depending upon the manufacturers of the device. PNP transistor in a TO-92 SOT54 plastic package.Electrons Emitted from Emitter Collected by the CollectorĮlectrons emitted from the emitter into the first PN junction
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