Small Signal Amplifiers

Amplifier Testing

Amplifier Testing: Preparation – Transistor Amplifier Testing and other circuits should be tested in a methodical fashion; otherwise the results obtained may be useless. The circuit should first be carefully constructed in bread-board form, placing the components to resemble the circuit diagram as closely as possible. This makes testing and troubleshooting much easier than when …

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Differential Amplifier Circuit using Transistors

Differential Amplifier Circuit using Transistors: The Differential Amplifier Circuit using Transistors is widely applied in integrated circuitry, because it has both good bias stability and good voltage gain without the use of large bypass capacitors. Differential amplifiers can also be constructed as discrete component circuits.   Figure 12-31(a) shows that a basic Differential Amplifier Circuit …

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BIFET Amplifier

BIFET Amplifier: BJT-FET Considerations : Two-stage BJT circuits usually have relatively low input impedances. To increase Zi, a field effect transistor may be used as the first stage. Circuits which are composed of BJTs and FETs are termed BIFET Amplifier circuits. Since a FET circuit normally has much lower voltage gain than a BJT circuit, …

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Direct Coupled Circuits

Direct Coupled Circuits: For economy, the number of components used in any circuit should be kept to a minimum. The use of direct coupling between stages is one way of eliminating components. Figure 12-20 shows a Direct Coupled Circuits that has the base of transistor Q2 directly coupled to the collector of Q1. Comparing this to …

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Single Stage Common Source Amplifier

Single Stage Common Source Amplifier: Bias circuit design for the Single Stage Common Source Amplifier in shown in Fig. 12-10. As with the common-emitter BJT circuit, design commences with specification of the supply voltage, amplification, frequency response, load impedance, etc. Selection of ID,RD, and Rs The circuit shown in Fig. 12-10 has no provision for …

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