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What is the basic current equation in a BJT transistor?
A transistors current gain is given the Greek symbol of Beta, ( β ). As the emitter current for a common emitter configuration is defined as Ie = Ic + Ib, the ratio of Ic/Ie is called Alpha, given the Greek symbol of α. Note: that the value of Alpha will always be less than unity.
Why is it called common base configuration?
The input signal is applied between the emitter and base terminals while the corresponding output signal is taken across the collector and base terminals. Thus the base terminal of a transistor is common for both input and output terminals and hence it is named as common base configuration.
Why is base lightly doped?
The base region in a transistor is doped lightly so that the number density of majority carriers (electrons in p-n and holes in n-p-n transistor) is low. When emitter is forward biased, the majority carriers move from emitter to collector through base.
How is the emitter current calculated in BJT?
Construction, Working & Applications It is the ratio of output current i.e. the collector current IC to the input current i.e. the base current IB. The emitter current is the combination of collector & base current. It can be calculated using any of these equations. ICEO is the collector to emitter leakage current (Open base).
What is the formula for the BJT formula?
It is the ratio of output current i.e. the collector current I C to the input current i.e. the base current I B. β F = h FE = I C /I B
What are the two types of current gain in BJT?
There are two types of current gain in BJT i.e. α and β. In common base configuration, BJT is used as voltage gain amplifier, where the gain AV is the ratio of output voltage to input voltage: What is NPN Transistor? BJT Construction, Working & Applications
How is the base current of a transistor determined?
The base current, IB, of a transistor is a crucial current of a bipolar junction transistor. Without this base current, the transistor can’t turn on. There are several ways to find the base current, IB, of a transistor. And it all depends on what information is already known about the transistor: