Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Zener diodes are used primarily as______.
Amplifiers
Voltage regulators
Rectifiers
Oscillators
Voltage regulators
Zener diodes are specifically designed to operate in the reverse breakdown region, known as the Zener region, where they maintain a nearly constant voltage across their terminals despite significant variations in input voltage or load current. This unique characteristic makes them the primary component in shunt voltage regulator circuits.
Zener diodes are specifically designed to operate in the reverse breakdown region, known as the Zener region, where they maintain a nearly constant voltage across their terminals despite significant variations in input voltage or load current. This unique characteristic makes them the primary component in shunt voltage regulator circuits.
VoutтАЛтЙИVzтАЛ тАФ The output voltage is approximately equal to the Zener breakdown voltage
IsтАЛ=IzтАЛ+ILтАЛ тАФ Kirchoff's current law at the regulator node
When a Zener diode is reverse-biased beyond its breakdown voltage (VzтАЛ), the electric field across the p-n junction becomes strong enough to cause Zener breakdown (quantum tunneling) or avalanche breakdown. In this state, the voltage drop across the diode remains remarkably stable at VzтАЛ, effectively clamping the output voltage. By placing a resistor in series with the input, the diode regulates the output voltage regardless of supply fluctuations.
Operates in the reverse breakdown region.
Maintains constant voltage VzтАЛ for variable current loads.
Must be connected in reverse bias mode (Cathode to positive).
Requires a series current-limiting resistor to prevent damage.
Simple circuit construction
Excellent reliability for low-power applications
Fast response time
Inefficient for high-power loads due to constant current draw
Voltage stability depends on temperature (Temperature coefficient)
Limited current handling capacity
Voltage regulation in power supplies
Reference voltage sources
Overvoltage protection circuits
Zener voltage is determined by the doping level of the semiconductor material during manufacturing.
Option A (Amplifiers) uses BJT/FETs, Option C (Rectifiers) uses standard PN junction diodes, and Option D (Oscillators) requires active gain elements like transistors/Op-amps.
B is correct тАФ Zener diodes are primarily used as voltage regulators because they maintain a constant reverse breakdown voltage.
Always ensure the series resistor is sized correctly (RsтАЛ=Iz,maxтАЛ+IL,minтАЛVin,maxтАЛтИТVzтАЛтАЛ) to keep the Zener current within safe limits during no-load conditions.