By contrast with the conventional device, a reverse-biased Zener diode exhibits a controlled breakdown and allows the current to keep the voltage across the Zener diode close to the Zener breakdown voltage. A Zener diode exhibits almost the same properties, except the device is specially designed so as to have a reduced breakdown voltage, the so-called Zener voltage. Unless this current is limited by external circuits, the diode may be permanently damaged due to overheating. When the reverse bias breakdown voltage is exceeded, a conventional diode will conduct a high current due to avalanche breakdown. Temperature coefficient of Zener voltage against nominal Zener voltage.Ī conventional solid-state diode allows significant current if it is reverse-biased above its reverse breakdown voltage. Operation Current-voltage characteristic of a Zener diode with a breakdown voltage of 3.4 V. Later, his work led to the Bell Labs implementation of the effect in form of an electronic device, the Zener diode. The device is named after American physicist Clarence Zener who first described the Zener effect in 1934 in his primarily theoretical studies of breakdown of electrical insulator properties. They are also used to protect circuits from overvoltage, especially electrostatic discharge. They are used to generate low-power stabilized supply rails from a higher voltage and to provide reference voltages for circuits, especially stabilized power supplies. Both breakdown types are present in Zener diodes with the Zener effect predominating at lower voltages and avalanche breakdown at higher voltages. Diodes with a higher Zener voltage have lighter doped junctions which causes their mode of operation to involve avalanche breakdown. Some Zener diodes have an abrupt, heavily doped p–n junction with a low Zener voltage, in which case the reverse conduction occurs due to electron quantum tunnelling in the short distance between p and n regions − this is known as the Zener effect, after Clarence Zener. Zener diodes are manufactured with a great variety of Zener voltages and some are even variable. In the line‐dominated regime, which corresponds to large AK gaps, the impedance is independent of the AK gap and corresponds to the impedance associated with the minimum current solution of the MITL, with the flow becoming more radial as the AK gap is increased.A Zener diode is a special type of diode designed to reliably allow current to flow "backwards" (inverted polarity) when a certain set reverse voltage, known as the Zener voltage, is reached. In the load‐dominated regime, which corresponds to small AK gaps, the diode impedance is controlled by an effective anode‐cathode gap, and the flow is approximately axial. The model agrees with the measurements within the 10% measuring error and shows that the diode operates in either a load‐ or line‐dominated regime depending on AK (anode‐cathode) gap spacing. The measurements were made on the 16‐Ω electron accelerator HELIA (high‐energy linear induction accelerator) operating at 3 MV. The impedance of a diode having an annular cathode and indented anode that terminates a coaxial MITL (magnetically insulated transmission line) is measured and compared with a semiempirical model developed from calculations made using the magic code.
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