RFZener Diode: Selection Guide, Applications, Benefits & Manufacturers
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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’ll explore how to select the right Zener diode, its various applications, benefits, and leading manufacturers. The list of vendors includes ON Semiconductor, NXP, ROHM, MACOM, Microsemi, Micro Commercial Components, Vishay, API Technologies, etc.
What is a Zener Diode?
A Zener diode is a specially designed, highly doped PN junction diode that normally operates in reverse biased condition.
The figure above depicts a Zener diode used in a voltage regulator circuit. The circuit symbol and equivalent circuit of a Zener diode are also shown in the figure.
The figure above depicts the V-I characteristic of a Zener diode. As shown, in the forward biased state, the Zener diode functions as a normal diode. In the reverse biased state, sharp breakdown takes place when the reverse bias voltage exceeds the Zener voltage (“Vz”) of the diode. At this point, the current increases very rapidly. Hence, it is also known as a “Breakdown Diode”.
Zener Diode Selection Guide
The following specifications or parameters are considered when selecting a 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 through it. It is equal to the product of the voltage across the diode and the current passing through it.
- Zener Resistance
- Voltage Tolerance
- Temperature Stability
- Package Type: SMD, through-hole packages based on design requirements.
Zener Diode Applications
Here are some key applications of Zener diodes:
- 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 Diodes
The following are some of the benefits of Zener diodes that make them a preferred choice in the electronics domain:
- Provides stable and accurate voltage output.
- Small size and affordable compared to other voltage regulation solutions.
- Operates consistently in various temperature and power conditions.
- Quickly reacts to voltage fluctuations to protect circuits.
- Minimizes power loss in voltage regulation applications.
- Can withstand repeated voltage breakdown without damage.
Zener Diode Manufacturers
The 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. • Visit the 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 the 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 a working voltage range from 2.4 V to 36 V. • Website: nxp.com |
| ROHM Semiconductor | • Part number: TFZV27B • The above part Zener diode offers high reliability and is a 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. • Visit the 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) • Visit the MACOM website for other Zener diodes as per requirements and complete specifications of the above part numbers. • Website: macom.com |
| Microsemi | • The company manufactures different types of Zener diodes for various applications, including voltage regulators, low voltage avalanche, temperature compensated, and so on. • Website: microsemi.com |
| Vishay Intertechnology | • The company manufactures Zener diodes in a 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.
