Zener Diodes
A Zener diode, also known as a voltage regulator diode, Zener voltage regulator, or power Zener diode, is a specialised type of semiconductor device designed to operate reliably in a reverse-biased condition. Unlike a standard diode, a Zener diode permits current to flow not only in the forward direction but also in the reverse direction once a specific voltage, known as the Zener breakdown voltage, is reached.
This unique characteristic allows it to maintain a constant voltage across its terminals despite fluctuations in the input voltage or load current.
Types of Zener Diodes
The variety of Zener diode types allows for their use in a wide range of applications, each designed to meet specific electrical requirements. From handling high power to fitting into compact circuits, these diodes are specialised for different functions.
Standard Zener Diode
A standard Zener diode is typically used in basic voltage regulation circuits. It maintains a constant output voltage across a varying input voltage and is characterised by a specific Zener breakdown voltage. These diodes are widely available and used for general-purpose electronic applications.
Low-Voltage Zener Diode
These diodes have a low Zener voltage, typically below 5 volts, and are primarily used in low-power circuits. They are crucial for protecting sensitive components from overvoltage and are often found in portable and battery-operated devices. Their small size and low power consumption make them ideal for compact designs.
High-Voltage Zener Diode
A high-voltage Zener diode is designed to operate at higher voltages to handle greater electrical stress without failure, suitable for circuits requiring more than 200 volts. They are utilised in applications such as power supplies and high-voltage regulation, where maintaining a stable output is critical.
Surface Mount Zener Diode (SMD)
An SMD Zener diode is a compact, leadless component designed for mounting on a PCB. Its small size makes it perfect for miniature electronics and high-density circuit boards, where space is at a premium. The surface mount Zener diode is a key component in modern consumer electronics and telecommunications devices.
Power Zener Diode
A power Zener diode is a type of Zener diode engineered to dissipate significant amounts of power. This makes it ideal for applications that require a robust voltage regulator diode, such as in power supplies and industrial equipment, where voltage regulation must be stable under high-current loads.
Temperature-Compensated Zener Diode
This specialised diode is designed to have a very stable voltage across a wide range of temperatures. It combines a Zener diode with a forward-biased diode in series to offset the temperature coefficient of the Zener voltage. This makes it an excellent choice for precision applications such as in laboratory instruments and high-accuracy reference circuits.
Bidirectional Zener Diode (TVS)
A bidirectional Zener diode, often referred to as a Transient Voltage Suppressor (TVS), is designed to protect circuits from high-energy voltage spikes in both the forward and reverse directions. It acts as a bidirectional clamp, providing overvoltage protection for sensitive components in power lines and data ports.
Applications of Zener Diodes
The ability of a Zener diode to maintain a stable voltage and absorb excess energy is crucial for the reliability of electronic systems, making it a mainstay in a wide range of applications.
Voltage Regulation
The most common application of a Zener diode is as a voltage regulator diode. By connecting the Zener diode in parallel with the load, it maintains a constant voltage across it, regardless of variations in the input voltage or load current. For example, a Zener voltage regulator circuit can be used to provide a stable 5V supply to a microcontroller from an unstable 9V battery source.
Voltage Shifting
A Zener diode can be used to shift the DC level of a signal. When a signal is applied, the Zener diode clamps the voltage at its Zener breakdown voltage, effectively shifting the baseline of the signal. This is useful in circuits where an analogue signal needs to be adapted to a specific voltage range for subsequent processing, such as in signal conditioning circuits for sensors.
Overvoltage Protection
Zener diodes are frequently used to protect sensitive electronic circuits from damaging voltage spikes. When the input voltage exceeds the Zener breakdown voltage, the diode "turns on" and clamps the voltage, diverting the excess current to ground. A small SMD Zener diode might be used to protect the input pins of an integrated circuit from static discharge.
Reference Voltage
The stable voltage across a Zener diode in its breakdown region makes it an excellent choice for a reference voltage source. This is critical for applications that require a precise and stable voltage for calibration or comparison. A power Zener diode, for example, is often used as a reference in power supply feedback loops to ensure a stable output voltage under varying load conditions.
Specialised Industry Applications
Beyond general electronics, Zener diodes play a crucial role in specialised industries. The high power Zener diode is used in automotive electronics for protecting sensitive circuitry from voltage transients on the car's power bus. In telecommunications, a surface mount Zener diode is essential for voltage clamping in small, portable devices.
Trusted and Reliable Distributor of Zener Diodes in Singapore
RS Singapore provides a comprehensive selection of Zener diodes for all your circuit design and voltage regulation needs. We are committed to offering high-quality components from leading manufacturers, ensuring you have access to the most reliable products on the market.
Our inventory includes Zener diodes from top brands like onsemi, Vishay, and Nexperia, each known for their exceptional performance and a wide variety of packages, from traditional through-hole to miniature surface mount Zener diode options.
Beyond our extensive range of Zener diodes, we also stock essential complementary products, such as fuse holder types for circuit protection and Schottky diodes for fast-switching applications, solidifying our position as your one-stop shop for all your electronic component needs.
For more information on our delivery options and fees, please visit our delivery page.
