Techniques for transient suppression diode selection and measurement of their good and bad
Transient suppression diode selection technique is every professional engineer should be the necessary skills, selection of professional engineers selection is a very simple and fast one thing. But for some small white engineers? Transient suppression diode selection and transient suppression diode selection is it is a very difficult thing. But here, Xiao Bian will tage technical skills to choose for the white engineer to explain the next transient suppression diodes, you look down:
Transient suppression 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 suppression diode rated reverse turn off 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 suppression diode clamp voltage should be less than the maximum VC protected damage voltage circuit.
4, in the prescribed pulse duration, TVS transient suppression diode maximum peak pulse power consumption of PM must be greater than the protection circuit may occur within the peak pulse power. In determining the maximum clamping voltage, 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 suppression diode device.
6, based on the use of TVS transient suppression diode polarity and encapsulation structure. AC circuit selection of bipolar TVS transient suppression diode is more reasonable; multi line protection using TVS transient suppression diode array is more favorable.
7, temperature considerations. Transient voltage suppressor can work in 55~+150 c.. If you need TVS transient suppression diodes in a changing temperature, due to the reverse leakage current of ID is increased with the increase of power consumption; with TVS transient suppression 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.
What about the above seven points? Hope that the engineers have to bear in mind. So small series and then talk about the transient voltage suppression diode measured how good or bad to judge it! We continue to look down:
TVS transient voltage suppression diode measured with good or bad:
1 with a multimeter R * 1K block measuring tube is good or bad for the unipolar TVS, according to the measurement method of ordinary diodes, can measure the reverse resistance, generally positive resistance is about 4k5, the reverse resistance is infinite.
2 for bi polar type TVS, freely red, black test to measure the resistance of the two pin between the values should be infinite, otherwise, that bad performance or damaged pipe.
For example: P6KE10CA this is a two-way TVS transient suppression diode so on the use of 2 methods.
The above for transient suppression diode selection technique and TVS transient voltage suppression diode is judged by the measurement of Shenzhen electronic engineers with years of experience to share, thank you all enjoy reading!
If the TVS diode selection procedures and type selection should pay attention to the problem does not understand, Xiao Bian recommend reading:http://www.dzhlw.com/295/337.html