PIN Diode – Features & Applications

PIN diode is characterized by fast low capacitance switching. A PIN diode is fabricated in a similar fashion to a silicon switching diode with an intrinsic region added between the PN junction layers. This generates a thicker depletion region, the insulating layer at the junction of a reverse biased diode. This results in lower capacitance than a reverse biased switching diode.

Fig: PIN Diode – its cross section alongside the schematic symbol

Applications of PIN Diodes

PIN diodes are used in a number of electronic systems, for example:

PIN diodes are utilized in place of switching diodes in radio frequency (RF) applications.
PIN diodes can serve as variable resistors when the forward bias is varied e.g. in a voltage variable attenuator. The low capacitance feature of PIN diodes extends the frequency flat response of the attenuator to microwave frequencies.
PIN Diode is also used as antenna switch for direction finder receiver.

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John Mulindi

John Mulindi is an Industrial Instrumentation and Control Professional with a wide range of experience in electrical and electronics, process measurement, control systems and automation. In free time he spends time reading, taking adventure walks and watching football.