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What would happen if both junctions of a BJT are forward biased?
If both junctions are reverse biased the transistor is switch off since the currents will be very small in the order of the reverse saturation current and the reverse is true that is the transistor will be switch on and saturated when the 2 junctions are forward biased.In this case the transistor currents are …
When both junctions of BJT is forward biased BJT is in?
When both junctions are forward biased it is called?
Saturation region The collector and Emitter currents are maximum in this mode of operation. The figure below shows a transistor working in saturation region. The transistor operates in saturation region when both the emitter and collector junctions are forward biased.
When both of the two junctions are forward biased the transistor is in the?
For a transistor to function, the two PN junctions must be properly biased. The base-emitter junction behaves like any other PN junction when viewed alone. If the base-emitter junction is forward biased, the transistor is on. If it is reverse biased, the transistor is off.
Is BJT a current controlled device?
A BJT is a current controlled device because its output characteristics are determined by the input current.
What are the two junctions of BJT?
The operational mode of the BJT depends on how the junctions between the regions are biased. Since there are two junctions, the emitter-base junction (EBJ) and the collector-base junction (CBJ), and each of these junctions may be either forward- or reverse-biased, there are four possible modes of operation.
What is the meaning of forward biased?
Forward biasing means putting a voltage across a diode that allows current to flow easily, while reverse biasing means putting a voltage across a diode in the opposite direction.
Does the current flow in forward biased?
Current only flows in one direction, Alongside the arrow, corresponding to forward bias. The cathode, bar, of the diode symbol, corresponds to N-type semiconductor. The anode, arrow, corresponds to the P-type semiconductor.
Where does the normal operation of the BJT occur?
It is also known as linear region. This region is in between the cutoff region and the saturation region. The normal operation of BJT occurs in this region. In saturation region, both of the junctions of the BJT are in forward bias. This region is used for the ON-state of a switch where;
What happens when forward bias is applied to the base-emitter junction?
When forward bias is applied to the base–emitter junction, the equilibrium between the thermally generated carriers and the repelling electric field of the n-doped emitter depletion region is disturbed. This allows thermally excited electrons (in an NPN; holes in a PNP) to inject from the emitter into the base region.
What are the regions of a BJT transistor?
The BJT is constructed with three doped semiconductor regions ( emitter, base, and collector) separated by two pn junctions. One type consists of two n regions separated by a p region (npn), and the other type consists of two p regions separated by an n region (pnp).
What happens when a BJT is used beyond its power rating?
When BJTs are operated beyond their power rating or reverse breakdown voltage then BJT will not work properly or may be damaged permanently. In case of reverse biasing, the emitter-base junction will cause avalanche breakdown which will permanently damage the current gain of the bipolar junction transistor.