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Something wierd about P6KE350A(unidirectional TVS diode)

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Em_13

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Hi,I have bought some 350V TVS diode,tested them with MM diode test ,but No flow passes from any side!Like it's bidirectional!
I also test them with 325 VDC and result was the same,No flow from both sides.
The TVS should transfer the current in one way after all,Regardless of diode clamping voltage value.isn't it the case that...?
 

Hi,

Hi,I have bought some 350V TVS diode,tested them with MM diode test ,but No flow passes from any side!Like it's bidirectional!
Click to expand...
--> test your MM with a usual Si diode.

I also test them with 325 VDC and result was the same,No flow from both sides.
Click to expand...
according datasheet: one direction should be conductive, but the other should be high impedance. It starts above 333V to become conductive.

Show us a photo of your diode and show us your complete test circuit.

Klaus
 
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    Em_13

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MM diode test works well with other si diode such as 4007,even work with P6KE400A and P6KE440A!
Here is my 350V diodes:
photo_2017-11-04_21-11-14.jpg

There is no specific circuit.The 350V Tvs diode doesn't flow current at both side.

- - - Updated - - -

Wiki says that TVS diodes work like a rectifier in forward direction.It makes me more astonished.Is it possible that all of my diodes in pack is broken?

ssss.JPG
 
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std_match said:
Fake or remarked components?
Click to expand...

There is no other scenario,I think you are right....It costs me about 20 IRF740 mosfet and a lot of time :bang:
 

Another possible explanation is that they are wrongly marked bipolar (CA type) TVS diodes. Did you check with higher voltage, e.g. 400 V? You can also measure capacitance to see if there is a diode chip connected at all.
 
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    Em_13

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FvM said:
Another possible explanation is that they are wrongly marked bipolar (CA type) TVS diodes. Did you check with higher voltage, e.g. 400 V? You can also measure capacitance to see if there is a diode chip connected at all.
Click to expand...
By the way I also connect them to 600 VDC ,and they pass current! Maybe you are right,The suffix is wrongly marked 8-O
 

A proper way to identify the actual component would be to measure the breakdown voltage at 1 mA current for both polarities and compare with datasheet specifications. It should be 350V +/- 10%.
 
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std_match said:
Fake or remarked components?
Click to expand...

The OP hasn't mentioned where he purchased the components, but unless they were purchased from a reputable vendor, I would also strongly suspect fake components.
 

Thanks guys.I threw all of them away,don't want to waste my money and time any more,At least i learn not to buy TVS diode via internet and go to store with my MM.
 
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If there is any consolation.....I would bet that most, if not all, of the people posting here have been burned by online purchases at least once.
 

Amen to that!!! Be wary of the fine print also.
 

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