What does a suppression diode do?
The Transient Voltage Suppressor diode (also known as a TVS Diode) is a protection diode designed to protect electronic circuits against transients and overvoltage threats such as EFT (electrically fast transients) and ESD (electro-static discharge).
What is TVS diode breakdown voltage?
The breakdown voltage (VBR) is the voltage where a TVS diode begins to conduct current, defined typically at 1 mA leakage. VBR defines the inflection point on the diode curve where the leakage beings to increase exponentially, which is typically referred as the diode ‘turning on’.
How do TVS diodes fail?
Transient voltage suppressors (TVS) will fail if they are subjected to conditions beyond their designed limits. In this case, the transient energy is large and of short duration that the silicon chip itself explodes. When a TVS device does short, follow-on operating current may cause the device to open.
How is TVS diode calculated?
Use the formulas in the TVS diode data sheet to calculate VCL.
- See the specifications for the SMAJ33A in Table 1.
- VCL(MAX) = VCL- RD × (IPP – IPPAPPLI) = 69.7V – 0.884Ω x (33A – 24A) = 61.7V.
- Confirm VCL < device abs max.
How to use TVS diodes for transient voltage suppresison?
The primary way to protect a circuit from overvoltage is to place these TVS devices in parallel with the circuit. There are many types of TVS device that can be used for Transient Voltage Suppression namely Metal Oxide Varistor, TVS Diode, Zener Diode or a Bypass Capacitor.
Why are TVS diodes in front of the load?
The TVS diodes specifically designed for transient voltage protection. The TVS diodes were located in front of the load to be protected and primarily served as a shunt path to ground for high surge currents that were generated by high-voltage transients such as inductive switching, induced lightning, and electro-static discharge (ESD) events.
Can a Zener diode be used as a transient voltage suppressor?
Although standard diodes and Zener diodes can both be used for transient protection, they are actually designed for rectification and voltage regulation, and, therefore, are not as reliable or robust as transient voltage suppressor diodes. Transient Voltage Suppressor (TVS) Diode Symbols: Unidirectional (left) and bidirectional (right).
What kind of diodes are used for ESD protection?
Transient Voltage Suppression (TVS) diodes are useful in protecting electronic circuits from electrostatic discharge (ESD). The TVS diodes used for ESD protection are silicon-avalanche diodes. With a high impedance at the stand-off voltage and low impedance at the breakdown voltage, silicon-avalanche diodes are well suited for ESD protection.