Zener diode - a protecting device against voltage transients

This paper begins with a discussion of the different modes of operation of a zener diode and continues with a study of its behavior during voltage transient conditions. A critique of the accepted electrical analogies of the thermal circuit of a zener diode is conducted, and the analysis of the thermal response of a zener diode to a power pulse is made in a highly simplified thermal model. A brief review of basic semiconductor knowledge is included as a frame of reference for the discussion of the causes of zener diode failure. The concept of zener diode failure produced by a high rate of rise of the junction temperature is introduced.