Answer Happy

QUESTION 1 (40 marks) The most important consideration in Power Amplifiers is the collector terminal efficiency of the amplifying component. In practice, among all Amplifier classes, the class A common emitter Amplifier is the least efficient with the highest collector deficiency which results in a lot of power and battery consumption, that come with high heat dissipation requirements. Yet, the class A common emitter Power Amplifier when designed correctly, is the most widely used to handle large signals and delivers more power gain for outdoor hi-fi musical systems. a. State why CE configuration is the most widely used connection for large signal BJT class A Amplifiers. (3 marks) b. Design a feasible class A silicon BJT Power Amplifier that provides a high voltage gain using 15 volts supply and employs a concept to increase its loaded efficiency to 50% so that little power loss is provided at the collector terminal. Given by manufacturer for safe operation, the amplifying component has a DC current gain of 200 and a collector current limit of 4mA. The output stage of the Amplifier drives a headphone with 32-ohms load impedance applicable for smartphones. (17 marks) c. Use a DC load-line to graphically find the three operating points of the amplifier. (5 marks) d. On the load line, sketch the respective AC signal at each operating point of the amplifier during its dynamic condition. (5 marks) e. Calculate the power rating and the maximum compliance of the amplifier. (5 marks) f. Refer to your design and state with reason, the components which affect the gain and shape of the output signal when the device responds to input signals at different frequencies within the audio range. (5 marks)