Forward bias is reduced, because, according to biasing law, V BE (voltages found parallel to emitter and base) are already negative with respect to ground.When the positive half of the signal combines with input: Figure 4.9 Circuit Operation of CB Amplifier Due to the E/B junction being forward biased, its impedance is low, while the impedance of the C/B junction is very high due to being reverse bias. E/B junction is forward bias through V EE while C/B junction is reverse bias through V CC. When input supplies a-c signals to the emitter-base junction, the output is received from the collector-base circuit (or parallel to the load resistor). In diagram 4.9, a single-stage amplifier circuit with an NPN transistor has been demonstrated. Since the base is common or grounded for both the signals, this circuit is also called a grounded circuit. The input signal is provided parallel to the emitter-base (EB) junction and the amplified output signal is received from the collector base (CB) junction. base is common both for emitter and collector on this circuit). In this circuit, the transistor is fitted in such a manner that the base is common or ground both between input and output circuits (i.e. When a transistor is desired to be operated as an amplifier, it is connected with any one of three following methods.Ībove mentioned 3 circuits have been shown in figure 4.8 Figure 4.8 one of the three terminals of a transistor is used for input and one for output, while the third one is used as a ground and which is common for both input terminal and output terminals) As there are just 3 terminals in a transistor, therefore it should be kept in mind that one of its terminals (called the ground terminal) is common with its input and output. (or amplifies it), thus an amplified electrical signal can be received between the other two output terminals. Its biggest advantage is that if a weak electrical signal is provided between its two input terminals, it magnifies the power of this weak signal. The detail is as belowīasically, a transistor can be utilized as an amplifier or as an amplifying unit. Transistor as an Amplifier:- Bipolar junction transistors are mostly used for amplification and switching purposes.

Bipolar Junction Transistor (BJT) As A Switch.Collector Curves and Operation Regions of Transistor.Comparison of CB, CE, and CC Amplifier Circuits :.

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