We have discussed the application of Zener diode as voltage regulator and now we will discuss the other two points. A Zener diode uses an effect related to field ionization involving a tunneling of the charge carriers. Applications of Zener Diode. Unlike a conventional diode where the intended use is to prevent current in the reverse direction, a zener diode is mostly used in the reverse region above the breakdown voltage. The reverse breakdown of a PN- junction may occur either due to Zener effect or avalanche effect. Let's have a look at what Zener Diodes are, and how they work! Hence, it has very thin depletion region. Through a non-permeable polarized p-n connection, a small reverse current of constant saturation flows. Commonly, Zener diodes are available with breakdown voltage between 1.8 to 200 Volts. but regulator because of their feedback charecteristic fix the volatage( the tolerance even below .1%) and higher current they can support but more expensive than zener. The equation is V = IR. What’s the difference between them? Apparently a zener diode will accomplish the same task as I have a device that uses these. The voltage specification of a zener diode is it's breakdown voltage, this is the voltage that the zener will pass. The Schottky barrier is a variant of the rectifier diode and is particularly popular in the field of digital electronics. But avalanche breakdown destroys the junction. As a result, it can undergo break down without being damaged. IN4728 zener diode has a breakdown voltage of 3.3 V. When reverses bias is occur and the input voltage is maximum AC at 5 Volts, then the value of the voltage across the IN4728 zener diode will remain at 3.3 V. When the reverse bias voltage starts to increase, the diode intentionally starts an avalanche effect at a … 8899 New Member. When a PN junction diode is reverse biased, the depletion layer becomes wider. Zener Diode as Voltage Regulator: Voltage regulator is a device which maintains constant output voltage without bothering about variation in input voltage and load current. Brian. Zener Diode Up to 100V Medium to High DC power regulation Silicon Avalance Diode (SAD), Transient Voltage Suppressor (TVS) Up to 600V Medium Lightning surge and voltage transient protection Diode Array Up to 50V Low (<50pF) ESD protection of high-frequency data circuits . If this reverse biased voltage across the diode is increased continually, the depletion layer becomes more and more wider. Over voltage protection is done by using Zener diodes because there is current flowing through the diode after the reverse bias voltage exceeds a certain voltage . Basically, in Switching diodes vs Rectifier diodes, the connections remain the same. Both the zener and avalanche effects are also dependant to some degree on the junction temperature of the diode. It is just the applications that differ. A characteristic zener diode for general purpose electronic circuits has the power rating of 500mW, BZX55 zener diode series or the larger 1.3W, BZX85 zener series are most commonly used zener diodes. In this circuit they have used a 5.1V zener diode, if you were to use a multimeter across Vout then you would measure 5.1V, all the other voltage is dropped across the other components in the circuit, in this case a 1K resistor. Another special type of diode called the Avalanche diode is used for circuit protection. Thus, as long as the current in the diode is limited the Zener diode will not destroy the junction. I have been looking at circuit protection using TVS and Zener diodes.. Zener vs Schottky vs Normal diode Diode is a semiconductor device with P-N junction. Zener-Diode: A Zener diode is made up of p-n junction but heavily doped compared to a normal diode. Zener Diode checking. From the I-V characteristics curve above, we can see that the zener diode has a region in its reverse bias characteristics of almost a constant negative voltage regardless of the value of the current flowing through the diode. LED vs Zener Diode. Regulators vs. Zener using Zener or regulator is depend on your application. 1. Zener effect dominates at reverse voltages less than 5 volt whereas avalanche effect dominates above 5 V. For example: When using led's taking power from a standard rx, a resistor soldered to one leg of the led will reduce the voltage to the required level. Zener Diode is a reverse-biased heavily-doped PN junction diode which operates in the breakdown region. Schottky Diodes and Zener Diodes are both diodes, and both are used in certain types of rectifier circuits, but they are completely different types of parts. The Zener Diode is used in its “reverse bias” or reverse breakdown mode, i.e. The I vs V characteristic curve is similar to ordinary diode. 2. 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