What is a TVS diode

What is a TVS diode

The TVS diode will be connected in parallel with the circuit to be protected. When the voltage exceeds the Avalanche breakdown level, the excessive current will be shunted directly. The TVS diode is a clamp that suppresses excessive voltage exceeding its collapse voltage. When the overvoltage disappears, the TVS diode will automatically reset, and the energy absorbed by it is much greater than that of a similar rated crowbar circuit.

TVS diode can be unidirectional and bidirectional. The unidirectional TVS diode is similar to a commutator when operating in the forward direction, but its design allows for a large peak current, and the instantaneous power of the 1.5KE series can reach 1500 W.

The bidirectional TVS diode can be regarded as two Avalanche diode with opposite polarity in series and then in parallel with the circuit to be protected. Although it is labeled as two diodes in the circuit, the actual component is to package the two diodes in the same packaging.

TVS diode overvoltage response speed will be faster than other overvoltage protection elements (such as Varistor or gas discharge tube). The actual clamping is only about one picosecond, but due to the inductance of the wires in the actual circuit, the protective components need to allow for a longer period of high voltage. Therefore, TVS diode is more suitable than other components to protect the circuit from rapid and destructive Voltage spike. For example, many decentralized circuits have such fast Voltage spike, which may be caused by internal or external factors, such as lightning or motor short circuit.

Transient voltage suppressors may be damaged if used in environments beyond their design conditions. There are three failure modes for transient voltage suppressors: short circuit, open circuit, and component derating.

TVS diode are often referred to as transorbs, or TransZorbs, a registered trademark of Vishay Semiconductor.