How Diodes and Transistors Differ From Each Other

Transistors and diodes are both semiconductor devices, and each component serves as an essential building block of countless electronics and circuits. While transistors and diodes are often found in similar applications, their roles and operations tend to differ from one another. In this blog, we will provide a brief overview of transistor and diode part types, allowing you to have a better understanding of their functionalities and differences.

In its most basic form, a transistor is a semiconductor device capable of either amplifying or switching electronic signals and electric power. The transistor features three terminals, one pair having voltage or current induced in order to control current through another pair. When used as an amplifier, the transistor is capable of providing an output power value that is higher than the input power value. While there are a number of transistor components that are individually packaged, a majority are embedded in integrated circuits.

There are many types of transistors and transistor arrays that may be used for diverse applications, and they may be categorized by a number of properties ranging from their structure to their amplification factor. The most common form of transistor is the metal-oxide-semiconductor FET (MOSFET) type, those of which account for nearly 99.9% of all transistors across the globe. The MOSFET transistor is constructed through the controlled oxidation of a semiconductor material such as silicon, and their insulated gate’s voltage determines the conductivity of the device. By adjusting conductivity through the application of specific voltage values, MOSFET devices may be used to either amplify or switch electronic signals.

Diodes are also a semiconductor device, and they feature two terminals that permit the conduction of current in a singular direction. To achieve asymmetric conductance, the diode may be designed with low resistance in one direction and high resistance in the other direction to impede current flow. Diodes may be a thermionic or semiconductor type, and each presents its own unique design. The thermionic diode is a type of vacuum tube that contains two electrodes, and such components utilize their construction to direct electrons in one direction from the cathode to the plate. The semiconductor diode, which is the most commonly used variation today, is one that utilizes a crystalline piece of semiconductor material and a p-n junction which is joined with two terminals. Diode arrays are also a form of diode device that may be found, and they are an assembly of numerous photodiodes which are placed in a linear array for spectrophotometer applications.

When comparing the transistors and diodes, it is important to note that the diode only features two terminals while the transistor features three. With such designs, the diode is capable of controlling the directional flow of current while a transistor may permit signals and power to be switched or amplified as needed. To form a diode, a P-type semiconductor is joined together with an N-type semiconductor. For transistors, a P- or N-type material may be layered between two P- or N- type materials on the opposite end. With the formation of the diode, such components only have one junction which is located between the P- and N-type semiconductor materials. Transistors, on the other hand, will have two formed junctions between the emitter and base and the base and collector.

Diodes may be considered a type of switch due to their method of operations, and they are commonly used for various applications such as radio demodulation, power conversion, reverse-voltage protection, over-voltage protection, logic gates, ionizing radiation detectors, temperature measurements, and much more. As transistors may serve as either a switch or amplifier, such devices are commonly found in digital circuits as an electronic switch or logic gate, and they may be used for oscillators, detectors, and modulators.

While transistors and diodes both provide their varying roles with their different construction, both devices may be found together in countless circuits and electronics of varying types. When you are searching for top-quality electronic components that you may steadily rely upon, look no further than ASAP Axis. ASAP Axis is a leading online distributor of all types of aviation tools that are required for aircraft maintenance, and we provide competitive pricing on adapter diode components, insulator transistor parts, and many other items. If there are particular parts or components on our website that you wish to procure, you may request a quote for your comparisons at any time through the submission of an Instant RFQ form and a team member will respond in just 15 minutes or less, 24/7x365.