About Silicon PN-Junction Voltage Clamping Diodes

 This document covers Silicon PN-Junction Clamping Diode surge protective components (SPCs) used in power and telecom surge protective devices (SPDs) and equipment ports. The following items are covered:

  • Technology variants
    • forward biased semiconductor diodes
    • Zener breakdown semiconductor diodes
    • avalanche breakdown semiconductor diodes
    • punch-through semiconductor bipolar junction transistor diodes
    • fold-back semiconductor bidirectional transistor diodes
  • Component construction
  • Characteristics
  • Ratings
  • Application examples

Introduction to Surge Mitigation Techniques

  This document describes the various surge mitigation (reduction) techniques available to the designer. The use of non-linear voltage amplitude limiting functions is the most commonly thought of approach for surge protection. However, today there are non-linear current amplitude limiting functions along with extensively used linear surge attenuating functions. Surge protection gurus like Ronald B. Standler (Protection of Electronic Circuits from Overvoltages, Chapter 13) and François Martzloff (Diverting Surges to Ground: Expectations versus Reality, Proceedings, Open Forum on Surge Protection Application, NISTIR-4654, August 1991) have both discussed the use of filters in surge protection and Standler (Protection of Electronic Circuits from Overvoltages, Chapters 12 and 14) has also analysed the common-mode surge protection given by EMC chokes and isolation transformers. Linear attenuating functions like filters and transformers do provide surge mitigation and could be classified as performing surge rejection.

The various types of surge mitigation only briefly described. References are given for more in depth descriptions of the mitigation functions.