This repository contains the code, design files, and documentation for a university project focused on creating a common emitter BJT amplifier using Proteus simulation software with PCB Implementaion

This project report primarily revolves around the construction of a common emitter BJT amplifier that meets specific criteria for gain and bandwidth. It encompasses the entire journey of creating this amplifier, starting from the initial idea to the final product. This comprehensive process includes defining design specifications, performing critical calculations, simulating the circuit, designing the PCB layout, physically building the amplifier, analyzing the results, and drawing meaningful conclusions.

The common emitter amplifier, a voltage amplification circuit, utilizes a three-terminal bipolar junction transistor in a single-stage configuration. Input signals are acquired through the base terminal, amplified output collected from the collector terminal, while the emitter terminal connects to both input and output sides.

The project aimed to implement a Common Emitter BJT amplifier with specific specifications:

• Voltage gain = 400
• Bandwidth of Low Pass Filter = 1.5kHz

• Understand the construction and working principle of BJT amplifiers.
• Calculate component values based on given specifications.
• Simulate the designed common emitter amplifier circuit using Proteus.
• Implement the circuit on a PCB layout.
• Compare theoretical and experimental results to refine the design.

• Gather information to compute component values.
• Select appropriate transistors based on calculated parameters.
• Develop a block diagram illustrating the amplifier and filter stages.
• Perform necessary calculations for component values.
• Simulate the circuit design using Proteus software.
• Implement the circuit on a printed circuit board.
• Conclude theoretical and practical performances.

The amplifier design utilized cascaded stages with buffer circuits to achieve the desired gain and bandwidth. The 2N3904 NPN transistor was selected for its suitable properties.

Simulation results closely matched theoretical values, with a gain of approximately 400 achieved. Several factors contributed to deviations between theoretical and practical values, including component availability, impedance mismatch, real-world component properties, temperature effects, component tolerance, instrumental errors, and random experimental errors.

• Sahan Lelwala
• Sanjula Lakpahana
• Telana Kuruwitaarachchi
• Nilmi Lakshani
• Madhavi Kumari