Benefits of Using a Field Effect Transistor (FET)
The field-effect transistor is a class of transistors, which uses an electrical field to regulate the flow of electrical current within a semiconductor device. Like most other devices designed to regulate the flow of electricity, FETs are very small, fragile devices with only two terminals: a source and a gate. These devices are very common in many different electronic applications and are used in applications where power drain or high currents are needed.
The main benefits of using a FET in your electronics design are: they are small, inexpensive, require little or no power for operation, have a fast switching time, provide a stable input voltage, and have high efficiency. On the downside, they can be rather sensitive to low levels of voltage on their input; can become damaged when exposed to moisture, are susceptible to heat, and have a low life span, lasting only as long as the lifetime of the semiconductor material from which it was made. Some small surface-mounted FETs can even burn up if exposed to high temperatures. They are also sensitive to changes in temperature above their specified temperature range.
A FET can also be described as a switching element that has two terminals, called a collector and emitter, which form an “intermediate” current path for a change in current flows through the input voltage. A FET will turn on when the input voltage to the semiconductor device reaches a threshold value, which is called a saturation point. When the input voltage falls below this point, the FET begins to turn off, thereby turning off the current flows through the semiconductor device. The advantage of the FET lies in its ability to handle both high and low levels of input voltage. In addition, the FET is a perfect candidate for pulse detection application, since it will remain on when the input pulse frequency approaches the saturation point.
One of the most important characteristics of a FET is its sensitivity to changes in the applied voltage across its terminals. Its sensitivity allows it to be used in a wide variety of electronic applications, including motor control, timing control, speech processing, touch screen display, motion detection, digital filtering, and many other microcontroller and microprocessor applications. The existence of a pulse width modulation (PWM) which varies across the range of voltages applied to the terminals is another feature of FETs that makes them ideal for many electronics applications. The presence of this low-level PWM signal which is supplied to the input and output terminals by the FET provides for a smooth transition from one input level to another, eliminating the abrupt “start and stop” actions which can often disrupt input or output transitions. This feature is especially important for applications where multiple different sources are utilized, such as in an automated control system.
There are many areas of electronic components in which a FET can be of benefit, however, these benefits occur when these devices are placed within integrated circuits. These devices make up the majority of the components found within electronic devices today, including microprocessors, integrated circuits, digital signal processors, programmable logic gates (PLGs), discrete transistors (DTRs), power management ICs, temperature shutters, thermal control ICs, temperature stabilize ICs and many others. In addition, FETs can provide solutions for many areas of non-manufacturing process technology, as well as provide solutions for many areas of service technology. Because of the benefits provided by this type of technology, many industries and companies utilize the output of a FET within integrated circuits for a variety of purposes, including computer science applications, computer hardware, electronic repair, electronic testing, and many others. While certain characteristics of FETs make them unsuitable for some applications, their flexibility, speed, on-chip bandwidth, and power-saving capabilities make them ideal choices for many applications, making them an industry standard.
As described above, the benefits that come from using a FET in the design of an electronic circuit are quite widespread, and their wide variety of applications makes them ideal for both basic and advanced circuit design. They are also well suited for numerous different voltage ranges, which allows them to be used in all types of electronics where power requirements are a concern. Because of their high reliability and endurance, low cost, and easy implementation in a wide range of circuits, they are an exceptionally flexible and useful component for the design of any type of electronic circuit. Further, due to their overall reliability and security, many organizations prefer to use bipolar transistors in applications where accuracy is not crucial.
