Characteristics of transient suppression diodes

Transient suppression diodes are characterized by fast response, small size, large pulse power, and low clamping voltage. Transient suppression diodes are widely used in the protection of semiconductors and sensitive devices. They are commonly used for the protection of two-pole power supply and signal circuits. They are basically used for diode protection after ceramic gas discharge tubes. They are also used directly by users. Primary protection of the product.

Let's share the selection tips for TVS diodes:

First, determine the maximum DC continuous operating voltage of the protected circuit, the rated standard voltage of the circuit, and the maximum tolerance.

Secondly, the rated reverse voltage of the transient suppression diode should be greater than or equal to the maximum operating voltage of the protected circuit. If the selected shutdown voltage is too low, the device may enter an avalanche or the reverse leakage current will affect the normal operation of the circuit. The serial connection is divided into voltages, and the divided currents are connected in parallel.

Second, the maximum clamping voltage VC of the transient suppression diode should be less than the calculated voltage of the protected circuit.

Third, the maximum peak pulse power consumption PM of the transient suppression diode must be greater than the peak pulse power that may be present in the protected circuit for the specified pulse duration . After the maximum clamp voltage is determined, its peak pulse current should be greater than the transient surge current.

Fourth, for the protection of the data interface circuit, care must also be taken to select a transient suppression diode device with a suitable capacitor C.

Fifth, the polarity and package structure of the transient suppression diode are selected according to the application. The bipolar transient suppression diode is more reasonable for the AC circuit, and the TVS array is more advantageous for multi-line protection .

Finally, regarding temperature considerations, the transient suppression diode can operate at temperatures from -55 to +150 °C. If the transient suppression diode is required to operate at a varying temperature, the reverse leakage current ID increases with increasing; the power dissipation decreases as the transient suppression diode junction temperature increases, from +25°C to +175°C, approximately The breakdown voltage VBR, which decreases linearly by 50%, increases with a certain factor with an increase in temperature. Therefore, the effect of temperature changes on its characteristics must be considered.