TVS diodes are electronic components used to protect sensitive electronic devices from high voltage transients. They can handle overvoltages faster than most other types of circuit protection devices. In the following, Lu Jing Semiconductors introduces several transient suppression diode selection techniques:
1, TVS diode rated reverse turn-off VWM should be greater than or equal to the maximum operating voltage of the circuit being protected. If the selected VWM is too low, the device may enter an avalanche or the reverse leakage current will affect the normal operation of the circuit. The voltage is connected in series and the current is divided in parallel.
2. Determine the maximum DC or continuous operating voltage of the circuit to be protected, the nominal voltage of the circuit, and the "high end" tolerance.
3. The maximum clamp voltage VC of the TVS diode should be less than the damage voltage of the protected circuit.
4, temperature considerations. Transient voltage suppressors can operate between -55°C and +150°C. If TVS is required to operate at a varying temperature, the ID of the reverse leakage current increases with increasing power consumption; the power consumption decreases with increasing TVS junction temperature, and decreases approximately linearly by 50% from +25°C to +175°C. The breakdown voltage VBR increases with temperature by a certain factor. Therefore, you must consult the relevant product data and consider the effect of temperature changes on its characteristics.
5. During the specified pulse duration, the maximum peak pulse power dissipation PM of the TVS diode must be greater than the peak pulse power that may be present in the protected circuit. After determining the maximum clamp voltage, the peak pulse current should be greater than the transient surge current.
6. Select the TVS polarity and package structure according to the application. It is more reasonable to choose bipolar TVS for the alternating current circuit; It is more advantageous to choose TVS array for multiline protection.
The above are six techniques for the selection of transient suppression diodes. If you encounter problems in the selection process, you can contact Lu Jing Semiconductor's official website customer service to learn more.
