Darlington Connected Output Transistors: High-power transistors usually have low current gains, so relatively large base currents must flow into Q2 and Q3 to supply a high load current. This means that the quiescent current through…

Direct Coupled Class AB Output Stage: The output capacitor in a capacitor-coupled power amplifier is a large expensive component that should be eliminated if possible. Figure 18-23 shows a Class-AB amplifier circuit with a Direct…

Capacitor Coupled Class AB Output Stage: The basic circuit of a Class-AB amplifier using a complementary emitter follower output stage and a Capacitor Coupled Class AB Output Stage load is shown in Fig. 18-18. The…

Complementary Emitter Follower Circuit: Two BJTs connected to function as Complementary Emitter Follower Circuit are shown in Fig. 18-17. Although one is npn and the other is prim the devices are selected to have similar…

Transformer Coupled Amplifier: Transformer Coupled Amplifier commences with the load resistance and output power, specification. A signal voltage amplitude may also be stated, as well as the upper and lower cutoff frequencies for the amplifier.…

Transformer Coupled Class B Amplifier: Class B Amplifier - The inefficiency of Class-A amplifiers is largely due to the transistor bias conditions. In a Class-B amplifier, the transistors are biased to cutoff, so that there…

Transformer Coupled Class A Amplifier: Class A Circuit - Instead of capacitor coupling, a Transformer Coupled Class A Amplifier may be used to ac couple amplifier stages while providing dc isolation between stages. The resistance…