There are many applications for one or two transistors. These can include voltage and current amplification useful for interfacing between other system blocks (perhaps ICs).
Described in this series was an easy to understand way of visualizing the operation of a bipolar transistor in its linear operating region. This technique can be applied to the design of simple as well as sophisticated circuits. We explored the Base, Emitter, and Collector impedances and an easy way to calculate the circuit’s ac voltage gain. Also included was a smattering of other related concepts to stimulate your creativity.
All circuit designs involve a series of tradeoffs that must be balanced to optimize performance. A few of the more important considerations have been suggested. A “good” design is one that does a reliable job with the least complexity, cost, power, size, etc.
As a general rule, high-performance circuits (e.g., high gain, wide bandwidth, low DC errors) are best approached with integrated circuit technology where using a large number of devices does not necessarily involve high cost or size. Of course, to justify the design of an IC solution requires sufficient volume, economic, or possibly reliability factors to make it practical.
Nevertheless, when interfacing existing IC components or sensors, it is sometimes advantageous to design simple “glue” circuits to make the transitions. This is where this tutorial should be most useful.