Zener Diode : Selection Guide, Applications, Benefits & Manufacturers

Introduction : Zener diodes are essential components in voltage regulation, circuit protection and signal processing. Unlike standard diodes, Zener diodes allow current to flow in reverse once the voltage exceeds a specific breakdown threshold. This unique property makes them crucial in electronic circuits that require precise voltage control. In this guide, we explore how to select the right Zener diode, its various applications, benefits and leading manufacturers. The list of vendors include ON semiconductor, NXP, ROHM, MACOM, Microsemi, Micro Commercial Components, Vishay, API technologies etc.

What is Zener diode ?

It is specially designed high doped PN junction diode. It normally operates in reverse biased condition.

zener diode voltage regulator

The figure-1 depicts zener diode used in a voltage regulator circuit. The circuit symbol and equaivalent circuit of zener diode is also shown in the figure.

zener diode characteristic

The figure-2 depicts V-I characteristic of zener diode. As shown, in forward biased state, zener diode functions as normal diode. In reverse biased state, shart breakdown takes place when reverse bias voltage exceeds zener voltage ("Vz") of the diode. At this point, current increases very fast. Hence it is also known as "Breakdown Diode".

Zener diode Selection Guide

Following specifications or parameters are considered for selecting the zener diode.
• Voltage (Vz) : Select a diode with a breakdown voltage that matches the desired regulation voltage.
• Current : Maximum current which can flow through the diode at Vz.
• Power rating or power dissipation : Maximum power which can be dissipated thorough it. It is equal to product of voltage across diode and current passing through it.
• Zener resistance
• Voltage tolerance
• Temperature stability
• Package type : SMD, through-hole packages based on design requirements.

Zener diode Applications

Some of the key applications of zener diode are as follows.
•  Voltage Regulation : Used as a voltage regulator to maintain a stable output voltage.
•  Surge Protection : Protects sensitive electronic components from voltage spikes.
•  Voltage Reference : Provides a stable reference voltage for operational amplifiers and other circuits.
•  Wave Shaping : Used in waveform shaping circuits to clip or limit voltage levels.
•  Switching Applications : Functions in switching circuits for logic control.
•  Overvoltage Protection : Prevents excessive voltage from damaging circuits in power supplies.
•  Current Regulation : Maintains a consistent current in some circuits, such as LED drivers.
•  Transient Voltage Suppression (TVS) : Used in transient voltage suppressor circuits to protect against ESD (Electrostatic Discharge).

Advantages of Zener diode

Following are some of the benefits of zener diodes which make them preferred choice in electronics domain.
1. Provides stable and accurate voltage output.
2. Small size and affordable compared to other voltage regulation solutions.
3. Operates consistently in various temperature and power conditions.
4. Quickly reacts to voltage fluctuations to protect circuits.
5. Minimizes power loss in voltage regulation applications.
6. Can withstand repeated voltage breakdown without damage.

Zener diode Manufacturers

Following table mentions Zener diode manufacturers with part numbers and technical features.

Zener diode Manufacturers Description
ON semiconductor • Part numbers : MMSZ52 ( 2.4 V to 110 V, 500mW rating ) , 1N5923B (zener voltage range: 3.3 V to 200 V) , 1SMB5937B (3.3 V to 200 V, 3W) , MMSZ4688 (1.8V to 43 V, 500mW rating) and so on.
• Refer website for other part numbers as per your requirements of zener voltage and other specifications.
• Website : onsemi.com
NXP semiconductor • Part number : BZX79-B62
• Specifications of above zener diode are as follows.
• Zener voltage : 62 V, Zener current : 5 mA, Forward voltage : 0.9V, Power : 500 mW and so on.
• Other part PZU11B3 available in SOD323F package. It offers 310 mW power dissipation and supports working voltage range from 2.4 V to 36 V.
• Website : nxp.com
ROHM Semiconductor • Part number : TFZV27B
• Above part zener diode offers high reliability and is small power mold type diode.
• Specifications : Pd = 500 mW, Vz (min) = 24.97 V, Vz(max.) = 26.26 V, Iz = 5 mA and so on.
• Refer website for datasheets of other part numbers TDZ12, EDZV13B, UDZV12B, KDZ20B and more.
• Website : rohm.com
Micro Commercial Components • Various zener diodes are available at different power ratings.
• Website : mccsemi.com
MACOM • Part number : CD4625 (Zener voltage : 5.1 V, Zener current : 0.25 V and power of 0.5 Watt )
• Part number : CS4713 (Zener voltage : 30V, zener current : 7.9 mA, Power : 0.5 Watt)
• Refer MACOM website for other zener diodes as per requirements and complete specifications of above part numbers.
• Website : macom.com
Microsemi • The company manufactures different types of zener diodes for various applications including voltage regulator, low voltage avalanche, temperature compensated and so on.
• Website : microsemi.com
Vishay Intertechnology • The company manufactures zener diodes in variety of packages such as glass, plastic and sinterglass. They are available for various power ratings from < 350 mWatt to > 500 mWatt.
• Website : vishay.com
API Technologies USA • Website : apitech.com

Conclusion

Zener diodes play a vital role in maintaining voltage stability and protecting circuits from voltage fluctuations. Selecting the right Zener diode depends on parameters like breakdown voltage, power rating and tolerance. Whether you are designing a power supply, voltage reference or surge protection circuit, choosing a high quality Zener diode from a reliable manufacturer is essential for optimal performance.

Zener diode Related links

Following references will help reader in understanding technology and terms behind Zener diode.
Zener Diode➤   Diode Tutorial➤   GUNN Diode➤   Tunnel Diode➤   PIN Diode➤   Impatt Diode vs Trapatt Diode vs Baritt Diode➤   Tunnel vs normal P-N➤   Schottky Diode➤   Varactor Diode➤  

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