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 diode can be used as _________.
voltage regulator
voltage regulator
Both
None
voltage regulator
A Zener diode is a specially doped semiconductor P-N junction diode designed to operate safely in the reverse breakdown region. When connected in reverse bias, it maintains a constant voltage across its terminals despite variations in input voltage or load current, making it ideal as a voltage regulator.
A Zener diode is a specially doped semiconductor P-N junction diode designed to operate safely in the reverse breakdown region. When connected in reverse bias, it maintains a constant voltage across its terminals despite variations in input voltage or load current, making it ideal as a voltage regulator.
VoutтАЛ=VZтАЛ тАФ Regulated output voltage equal to Zener breakdown voltage
ISтАЛ=RSтАЛVinтАЛтИТVZтАЛтАЛ тАФ Total series loop current
ISтАЛ=IZтАЛ+ILтАЛ тАФ Current division at the load node
When the reverse bias voltage applied across a Zener diode reaches its Zener breakdown voltage (VZтАЛ), avalanche and Zener breakdown mechanisms occur, causing a steep rise in current. Despite this significant change in current (IZтАЛ), the voltage across the diode remains virtually constant at VZтАЛ. This constant voltage characteristic in the reverse breakdown region is utilized to maintain a stabilized output voltage across a parallel load.
A Zener diode must always be connected in reverse bias to function as a voltage regulator.
The series resistor (RSтАЛ) is essential to limit the Zener current (IZтАЛ) within safe power dissipation limits.
Zener voltage breakdown occurs at low reverse voltages (below 6V) due to strong electric field emission.
Simple, compact, and low-cost voltage regulation circuit.
Provides stable output voltage over a reasonable range of input voltages and load currents.
Low efficiency for high power loads due to continuous power dissipation in RSтАЛ and Zener.
Output voltage regulation degrades at very high load currents.
Voltage regulation in low-power DC power supplies.
Over-voltage protection circuits and reference voltage generators.
Waveform clipping and clamping networks.
Zener breakdown occurs in heavily doped diodes at thin depletion layers (<6V), whereas Avalanche breakdown occurs in lightly doped diodes at higher voltages (>6V).
Options B, C, and D are incorrect or duplicate entries; voltage regulation is the primary standard function of a Zener diode.
A is correct тАФ Zener diode operates in reverse breakdown region to maintain a constant output voltage, making it an effective voltage regulator.
In competitive exams, remember that a normal PN junction diode burns out during breakdown, but a Zener diode is specifically engineered to operate continuously in reverse breakdown without damage.