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When does the base current control the collector current?
The base current controls the collector current when the transistor is in the active region. A transistor is made up of two PN junctions, an emitter junction and a collector junction.
What causes an increase in collector current in BJT?
1.) BJT (with collector resistor): Increasing Vbe (or Ib) leads to rising collector current Ic, which causes a continuous decrease of the collector-emitter voltage Vce – until a lower limit is reached at app. (0.4…0.6)volts. A further increase in input voltage/current does not cause a further increase of Ic.
How does a base current control a transistor?
Transistors are controlled by a voltage applied between the emitter and base. The current is a parasitic effect caused by internal recombination of charges. This recombination isn’t generally desired, but it is always present in an active BJT.
What is current in saturation and active regions of BJT?
In the image ( http://www.allaboutcircuits.com/vol_3/chpt_4/4.html ), the result of SPICE simulation for active mode operation of BJT is shown. The current source is set at a constant value of 20uA and the collector bias voltage is varied from 0 to 2V.
Why does base current increase in a transistor?
3 Answers. An increase in this voltage results in increased currents in both the base and the collector, and indeed, an increase in base current causes an increase in B-E voltage. But the base and collector currents generally have a fixed ratio to each other for any particular transistor under a particular set of conditions,…
How is the current of a transistor controlled?
Transistors are controlled by a voltage applied between the emitter and base. The current is a parasitic effect caused by internal recombination of charges.
Where is the base emitter junction in a transistor?
From what I know for an npn transistor in the common-emitter connection the base-emitter junction is in the forward bias and the base-collector junction in the reverse.