0
\$\begingroup\$

TVS diode with marker

Some components that are needed to be be in a certain direction (like most diodes, and some capacitors) there is a white line over the component to show the direction.

But why is this done for a P6KE43CA, Bi-Directional TVS Diode, 600W, 2-Pin DO-204AC like the picture below. Does the direction matter since it is bidirectional?

enter image description here

TVS diode without marker

This is how mine look like from P6KE15CA; sorry for the bad picture, I do not have the TVS diodes at hand so used a screenshot crop from the page I bought them from:

enter image description here

\$\endgroup\$
5
  • 1
    \$\begingroup\$ Your link is broken. \$\endgroup\$
    – Hearth
    Commented Oct 11, 2018 at 12:57
  • 3
    \$\begingroup\$ Do you have the part in your hand and can see the direction marker on it? It's possible they're using a generic image for the entire series, which includes both unidirectional and bidirectional devices. \$\endgroup\$
    – Hearth
    Commented Oct 11, 2018 at 13:08
  • \$\begingroup\$ @Felthry I don't have them at hand, just found a similar ones when I noticed the clear line. I updated my question with the ones I have. \$\endgroup\$
    – Michel Keijzers
    Commented Oct 11, 2018 at 13:14
  • 1
    \$\begingroup\$ Those don't appear to have a direction marker. \$\endgroup\$
    – Hearth
    Commented Oct 11, 2018 at 13:15
  • \$\begingroup\$ @Felthry True, that's why I thought maybe for BIdirectional diodes it does not matter, since they are bi-directional anyway. \$\endgroup\$
    – Michel Keijzers
    Commented Oct 11, 2018 at 13:16

3 Answers 3

Reset to default
6
\$\begingroup\$

In all likelihood, the site you linked to is simply using a generic picture for the entire P6KE series, which includes both unidirectional and bidirectional devices. As your second image shows, P6KExxCA devices do not have a direction marker.

enter image description here

This excerpt from the datasheet provides further evidence of this. The unidirectional devices in the series do have a direction mark, but the bidirectional ones do not.

Generally, don't trust the images on distributors' websites, especially if they appear to be CG rather than actual photographs of the product. And even photographs can lie; I've come across a part with a picture of a large contactor that was actually a mechanical hole seal! Always check the details and datasheet.

\$\endgroup\$
1
  • \$\begingroup\$ Thanks for this answer ... that means the direction is not important (which I expected). \$\endgroup\$
    – Michel Keijzers
    Commented Oct 11, 2018 at 13:45
4
\$\begingroup\$

The DESD5V0U1BL-7B also has a cathode marking despite being bidirectional. I emailed the DIODES product team asking why they put the marking on the product. They responded with the following:

This is a pin#1 bar that may help customer’s vision system. There is no difference in functionality. Customer can ignore this pin#1 marking.

By vision systems I am assuming they mean pick and placers for automated BCP building.

\$\endgroup\$
1
  • \$\begingroup\$ It sounds plausible, thanks for adding the late answer (upvoted). \$\endgroup\$
    – Michel Keijzers
    Commented Sep 30, 2021 at 21:36
1
\$\begingroup\$

Bidirectional TVS has no specific direction.

enter image description here

To verify, someone can use DVM. Both directions of the bidirectional TVS will give voltage drop. Directional diode can give voltage drop in only one direction (forward biased).

\$\endgroup\$
1
  • \$\begingroup\$ Okay, but why would a bidirectional TVS have a direction mark? \$\endgroup\$
    – Null ♦
    Commented Jan 19, 2022 at 13:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.