Transient voltage diode(TVS) is a type of high-efficiency protection device in the form of diode. TVS is mainly used for fast overvoltage protection of circuit components. Because it has a fast-response speed, large transient power, low leakage current, low breakdown voltage deviation, clamping voltage control more easily and without damage to the limit, small volume, it has been widely used in communications equipment, AC/DC power supply, automotive, instruments and meters (meter), sensor/transmission, industrial control circuit, relay and other fields.