It is not. You have something confused.
It is not called that.
Because of the geometry of the common collector configuration, changes in base voltage appear at the emitter. Said another way, what happens at the base pretty much happens at the emitter, and the emitter can be said to "mirror" or "follow" the base. The emitter is a follower of the base, and the name emitter follower appeared and was used.
we should be take two point from the the graph between collector current and emitter-collector voltage.. along the horizontal line collector current is zero and emitter-collector voltage become Vcc,and along the vertical line emitter-collector voltage is zero and collector current become Vcc/RL then by this line that drow between this two point is called load line that in this line the transistor allowed to operate....
Common base transistor if the emitter is open current Ie=0 but a small collector current thus exist.this current is reversed biased collector to the base voltage it is represented by Icbo while common emitter is d base terminal is open circuit and the base junction is reversed biased current Icbo flow from the tcollector to the emitter in the external circuit this current is called leakage current.
The change of collector current with respect to emitter current. Typically 0.95 to 0.995. So a transistor with alpha of 0.95 might have an emitter current of 10 mA, collector current 9.5 mA. The "missing" current becomes base current and does not reach the collector. The more commonly used figure for current gain is beta, the ratio of collector current to base current, typically 50 to 500. In CB MODE It is called the common base, short-ckt, amplification factor.
The transistor has three regions, emitter,base and collector. The base is much thinner than the emitter while the collector is wider than both. However for the sake of convenience the emitter and collector are usually shown to be of equal size. The transistor has two pn junctions that means it is like two diodes. The junction between emitter and base may be called emitter-base diode or simply the emitter diode.The junction between base and collector may be called collector-base diode or simply collector diode. The emitter diode is always forward biased and the collector diode is always reverse biased.
Icbo (collector to base current when emitter is open) also called reverse saturation current as Is in reverse bias p-n junction diode.Regards
A: All transistor experience some kind of leakage with the one of the three termianal open. it called Iceo.
It's called saturation because the collector voltage cannot go any lower. You've done all you can do with your base current (in Common Emitter configuration) to lower the collector voltage and support the collector current.
The base.
A transistor can electronically switch the output by controlling the flow of current between its two terminals, called the collector and emitter. It has a third terminal, called the base, which acts as a control input. When a small current is applied to the base terminal, it influences the flow of current between the collector and emitter terminals, effectively turning the transistor "on" or "off" and allowing it to change the output state.
You can use a transistor as a diode if you connect the base to the collector. Any forward current through the base-emitter junction would cause a corresponding increase in the available current through the collector-emitter junction. Since the base-emitter and collector-emitter junctions are in parallel, this would effectively be a diode, but a true diode would be a better solution if diode functionality is what seek. A: There are actually two diodes, per se, inside a transistor. The base to emitter diode will suffice. By tying the collector to the base it will in effect be two diodes in parallel.