What happens when collector base junction is forward bias?
Forward bias on the emitter to base junction causes the electrons to flow from N type emitter towards the bias. This condition formulates the emitter current (IE). Rest of the electrons cross the thin depletion region and reach the collector region.
Is PNP transistor forward bias?
Construction of PNP Transistor: The emitter and base junctions are forward biased, while the collector and base junctions are reverse biased. The forward biased emitter attracts electrons to the battery, causing current to flow from the emitter to the collector.
How to switch on a pnp / npn transistor?
To switch on any transistor PNP/NPN, you need to forward bias the base emitter junction so for PNP emitter is +ve and base is -ve so to forward bias connect emitter to +ve supply and base to ground with resistor (see attached image) similarly for NPN connect emitter to GND and supply +ve voltage to base
Why is the base voltage of a PNP transistor always negative?
The voltage between the Base and Emitter ( VBE ), is now negative at the Base and positive at the Emitter because for a PNP transistor, the Base terminal is always biased negative with respect to the Emitter. Also the Emitter supply voltage is positive with respect to the Collector ( VCE ).
What is the purpose of forward biasing in a transistor?
This is forward biasing the base-emitter junction and reverse biasing the collector base junction. This allows for maximum current flow between the emitter and the collector, and what we’ll find is that it is almost the same current that is going through the emitter will be in the collector as well to add up on the next screen.
What is the saturation region of a PNP transistor?
Therefore the transistor is switched “Fully-ON”. Then we can define the “saturation region” or “ON mode” when using a bipolar transistor as a switch as being, both junctions forward biased, VB > 0.7v and IC = Maximum. For a PNP transistor, the Emitter potential must be positive with respect to the Base.