TVS is an acronym for Transient Voltage Suppression/Suppressor. TVS Diodes are a semiconductor device designed to limit or stop surges above a specific voltage level. The items in this family are designed using diodes (a component that conducts in just one direction).
Voltage Regulator Diodes, also known as Zener diodes, are designed for operation in a reverse-breakdown mode and are characterized according to their behavior when used in this fashion. Useful as a voltage reference or for voltage limiting purposes, they are also capable of functioning as a one-way valve for current flow in the manner of rectifier diodes.
The main differences between TVS and bidirectional zener diodes are as follows:
1. Working principle:
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TVS diode: When the voltage across it exceeds a specific breakdown voltage, the TVS diode quickly reduces its impedance and absorbs the transient overvoltage pulse to limit the voltage to a safe range. Its reaction time is very fast, usually in the picosecond (10-12 seconds) level, and it can handle high-energy transient pulses.
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Zener diode: When the reverse voltage reaches its breakdown voltage, the Zener diode maintains a stable voltage and allows current to pass. Its main function is to stabilize the voltage, and it is usually used in voltage reference or voltage stabilization circuits.
2. Application scenarios:
- TVS diode: Mainly used to protect circuits from transient overvoltages, such as voltage spikes caused by Electro-Static Discharge (ESD), lightning strikes, or switching operations. They are commonly found in the protection circuits of communication equipment, computers, and other electronic devices.
- Zener diodes: Mainly used to provide a stable reference voltage or stabilize the output voltage in the power circuit, and are widely used in power management and signal processing circuits.
3. Current handling capacity:
- TVS diodes: Able to withstand large instantaneous surge currents, usually up to hundreds of amperes, and can operate at high power.
- Zener diodes: Their current handling capacity is usually small, and they are mainly used to stabilize currents in a small range.
4. Classification:
- TVS diodes: Can be divided into unidirectional and bidirectional, depending on application requirements.
- Zener diodes: Can be divided into low-voltage and high-voltage Zener diodes according to the level of the regulated voltage.