30 January 2018

Characteristic of BJT

Before we check the characteristics you should know the BJT full meaning. It is helpful to view the characteristic curves of the transistor in graphical form is very similar to the graphical approach used with diodes. 

Now we can check it out the characteristics of BJT. 

BJT Input characteristics :




BJT Input characteristics
  • A graph of base current IB Vs base-emitter voltage VBE gives input characteristics. 
  • Since a transistor's base-emitter junction is like a diode IB versus VBE graph resembles a diode curve. 
  • When collector-emitter voltage VCE2 is more than VCE1, base current, for the same VBE, decreases as shown in the figure. 

BJT Output characteristics :



BJT Output characteristics
  • A graph of collector current IC Vs collector-emitter voltage VCE gives output characteristics.
  • For zero base current, for example, I= 0, as  VCE is increased, a small leakage (collector) current exists as shown in the figure.
  • As the base current is increased from IB = 0 to IB1, IB2 etc, collector current also rises as shown in Figure.