Quasi Complementary Push Pull Amplifier: In practical power amplifier circuits, it is preferable to employ NPN transistors for both high-current output devices. As the push-pull connection needs complementary devices, a PNP high power transistor is required. A practical means of having complementary operation while using the same, matched NPN transistors for the output is provided […]
Large Signal or Power Amplifiers
Complementary Symmetry Push Pull Amplifier: The use of transformers, at input as well as at output ends, in the push-pull amplifier shown in Fig. 17.25 makes it bulky and expensive especially in this age of the integrated circuits. Another drawback of the circuit given in Fig. 17.25 is that it needs two out-of-phase signals which
Phase Splitter Circuit for Push Pull Power Amplifiers (or Phase Inverter): In a push-pull amplifier circuit an input transformer is used to provide the polarity inversion between the two input signals to the push-pull circuit, but the transformer is quite expensive and bulky. The same result may be achieved by using a circuit called the
Class AB Push Pull Amplifier – Circuit Diagram, Operation and Drawbacks: The basic circuit of class AB push-pull amplifier is the same as that of class A push-pull amplifier shown in Fig. 17.25 except that the voltage drop across resistor R2 is so adjusted that it is approximately equal to cutin voltage (0.5 V for
What is Crossover Distortion and how to eliminate it? In addition to the distortion introduced due to the nonlinearity of the collector characteristics and due to non-matching of the two transistors, there is one more source of distortion, that is caused by nonlinearity of the input characteristic. Recall that silicon transistors must have at least
Class B Push Pull Amplifier – Circuit Diagram, Operation and Derivation: The circuitry for the Class B Push Pull Amplifier operation is the same as that for the class A operation except that the devices are biased at cutoff. The transistor circuit of Fig. 17.25 operates as class B if R2 = 0 because a transistor
Class A Push Pull Amplifier – Working Principle, Advantages & Disadvantages: A Class A Push Pull Amplifier circuit is shown in Fig. 17.25. By Class A Push Pull Amplifier means that current flows in the output of the active device (each transistor) for the entire of the input cycle. Circuit Arrangement: The circuitry of a
Push Pull Amplifier – Circuit Diagram and its Workings: As we know already that, double-ended or push pull amplifiers makes use of two identical transistors in a single stage. It consists of two loops in which the transistor collector currents flow in opposite directions but add in the load. Push Pull Amplifiers eliminate all of the three drawbacks.
Class D Power Amplifiers – Circuit Diagram, Operation and Applications: Historically, audio amplifiers have been configured as class A, class B or class AB and the art of design is well known. Also well known is the poor efficiency of these amplifiers compared to that of class D amplifiers. Whereas the theoretical best efficiency for
Class AB Power Amplifier Working Principle: In class AB power amplifier, the biasing circuit is so adjusted that the operating point Q lies near the cutoff voltage. During a small portion of negative half cycle and for complete positive half cycle of the signal, the input circuit remains forward biased and hence collector current flows.