TVS transient diode selection technique
1. Determine the maximum DC or continuous operating voltage of the protected circuit, the rated voltage of the circuit and the tolerance of the "high end".
2, TVS transient diode rated reverse turn off the VWM should be greater than or equal to the maximum operating voltage of the protected circuit. If the selection of VWM is too low, the device may enter the avalanche or the reverse leakage current is too large to affect the normal operation of the circuit. Serial connected sub voltage, parallel connection current.
3, TVS transient diode clamp voltage should be less than the maximum VC protected damage voltage circuit.
4, in the prescribed pulse duration, the maximum peak pulse power TVS of the PM transient diode must be greater than the peak pulse power which may occur in the protected circuit. The maximum clamping voltage is determined after the peak pulse current should be greater than the transient surge current.
5, for the protection of the data interface circuit, we must also pay attention to the selection of a suitable capacitor TVS C transient diode device.
6, according to the use of TVS transient diode and the polarity of the package structure. AC circuit selection of bipolar TVS transient diode is more reasonable; multi line protection using TVS transient diode array is more favorable.
7, temperature considerations. Transient voltage suppressor can work in 55~+150 c.. If you need a TVS transient diode in a changing temperature, due to the reverse leakage current of ID is increased with the increase of power consumption; with TVS transient diode junction temperature decreases from +25 DEG to +175 DEG, approximately linear decrease 50% rain breakdown voltage VBR with the increase of temperature in a certain coefficient increases. Therefore, it is necessary to consult the relevant product information, consider the impact of temperature changes on its characteristics.