Two of the most often used amplifier building blocks in audio amplifier design are the common emitter amplifier with emitter degeneration and the emitter follower using the same circuit biasing.

Last time on Circuit VR, we looked at creating a very simple common emitter amplifier, but we didn’t talk about how to select the capacitor values, or much about why we wanted them. We are going ...

Just as the common emitter amplifier and common base amplifier each tied those respective transistor terminals to a fixed potential and used the other two terminals as amplifier input and output ...

Immediately, I learned that the common base configuration gain was 6db lower than the common emitter. This blew my mind. Then I started checking input resistance and was shocked at how low it measured ...

PartSim is used in this example to simulate the Common Emitter Amplifier. The base bias voltage is set with the voltage divider arrangement. The input signal is amplified by the 2N2222 NPN transistor.

The circuit in Figure 1 sinks a constant current (ICE3) through Q3’s collector and emitter. This design is balanced so changes in Q3’s base-emitter voltage (VBE) don’t affect the current ...