Clamp diode is TVS canal actually, namely the abbreviation that transient state restrains diode (Transient Voltage Suppressor) . Develop on the foundation of stabilized voltage diode and it comes, the new-style tall efficiency that is form of a kind of diode protects parts of an apparatus, be restricted namely of profiling control protective parts of an apparatus too.

 

TVS is used normally 22 extremely the axial that provides form | The line encloses a structure, also have stick piece, the core unit of TVS is chip, chip has sheet pole model and ambipolar model two kinds of structures, sheet pole TVS has tie of a PN, ambipolar model TVS has two PN to written guarantee. Odd polarity is only right the surge voltage of a direction protects action since concussion, bipolar.

 

Transient state diode has protective effect to impact of adverse polarity surge voltage, be equivalent to two stabilized voltage running retrorse series. The characteristic with this kind of outstanding canal has puncture report depress, noise to answer namely time is class of amount of a few Ps, leakage current power of small, transient state is great, wait for a characteristic without noise, because this is inside signal system,get applied extensively reaching admissive.

 

Will understand two first below – diode establishs ties reversely moment is how of the job, following graph D1 and D2 two – diode establishs ties together reversely, this belongs to clamp protective circuit, advantageous also with this kind of clamp will had taken 0 signal, in clamp in circuit, ground connection of diode negative pole, criterion positive electrode carries circuit by clamp time of work of the following; can have 0 potential only a diode guides, and another is in off-state, so its pressing reversely fall to be able to be in by clamp down on diode guide is connected pressure fall if 0.5-0.7 (guides pressure falling is this) the following, rise to protect the purpose of circuit thereby.

 

 

Following graphs are the voltage that TVS is in charge of- – electric current is characteristic. Below the action of surge voltage, TVS canal is polar between voltage by rated and retrorse when closing voltage VWM_ to rise to puncture voltage VBR by puncture, appeared puncture electric current, , the electric current that has shed TVS canal then will achieve IPP of electric current of peak value pulse, its the voltage of two end also is located in to book by clamp most tongs voltage VC is the following. Press exponential attenuation as pulse electric current ever since, TVS is in charge of polar voltage to also drop ceaselessly, restore finally first voice, this is TVS canal controls power of pulse of surge electric current, protect the principle of electronic parts.