What is reverse bias in NPN transistor?
Working of NPN Transistor As shown in the above figure, the emitter to base junction is forward biased and the collector to base junction is reverse biased. 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).
What is a reverse bias?
Reverse bias is when the p-side of the diode is connected to the negative voltage of the battery and the n-side is connected to the positive voltage of the battery. This causes an increase in the thickness of the depletion layer. This allows very less current to flow through the PN junction.
Is VBE always 0.7 V?
It isn’t a constant 0.7V, and your quotation doesn’t say otherwise. It is fairly constant within about +/-10% of that, for small signal NPN transistors, so 0.7V is used as a simplifying assumption, which is what your quotation actually says. For the transistors I usually use it varies between 0.2-0.65V.
How does NPN transistor work?
The NPN transistor is designed to pass electrons from the emitter to the collector (so conventional current flows from collector to emitter). The emitter “emits” electrons into the base, which controls the number of electrons the emitter emits.
How is a transistor reverse biased?
A transistor is a three terminal device. One terminal is called emitter, one collector and in between them is base. Now, during biasing the junction between emitter and base is made forward biased and the junction between collector and base is made reverse biased.
Which junction of the transistor is reverse biased?
No current will follow into the base when the emitter-base junction of a transistor is reverse biased. When no current is flowing into the base, no current will flow in the collector. Now if the collector is also reverse biased, then the collector current will flow. This is called reverse active biasing.
Why do we use reverse bias?
A reverse bias reinforces the potential barrier and impedes the flow of charge carriers. In contrast, a forward bias weakens the potential barrier, thus allowing current to flow more easily across the junction.
What is forward bias and reverse bias in transistor?
In forward biasing the positive terminal of the battery is connected to the p-region and the negative terminal is connected to the n-type material while in reverse bias the positive terminal of the supply is connected to the n- type material and the negative terminal is connected to the p-type material of the device.
What is the difference between a PNP and NPN transistor?
In an NPN transistor, a positive voltage is given to the collector terminal to produce a current flow from the collector to the emitter. In a PNP transistor, a positive voltage is given to the emitter terminal to produce current flow from the emitter to collector.