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I was looking for a SMD diode to add reverse-polarity protection to a circuit I was designing, and the PMEG3020CPA looked like a good fit with regards to my current and voltage needs.

What confused me is why the data sheet shows two anodes, so I have a few questions about that:

  1. Are the two anodes meant to be connected? E.g. the two internal diodes would be in parallel. Or should only one be used?
  2. Are the current and voltage ratings given for each of the internal diodes, or both together?
  3. Why is it designed or diagramed like this?

I ran into this question about three-terminal diodes but that seemed to be one diode and a floating third pin, which isn't really relevant.

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It's a dual diode. There are two diodes in one package.

enter image description here

You can parallel them if you want (connect 1 and 2) but there is no matching characteristics given, so you can't really depend on the rating to be much better, and the leakage will definitely double.

The characteristics are for each device, however they are (obviously) tightly thermally coupled so the total power dissipation will have to be taken into account.

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    \$\begingroup\$ You'd think that the "dual" in the description would give it away... \$\endgroup\$ – Ignacio Vazquez-Abrams Jan 26 '16 at 15:44
  • \$\begingroup\$ what would be the typical use for that beast? combining 2 voltage sources? \$\endgroup\$ – nraynaud Jan 26 '16 at 15:50
  • \$\begingroup\$ Rectifier is one thing, as well as everything the application notes says in the datasheet first page, and likely more.... \$\endgroup\$ – Iancovici Jan 26 '16 at 15:52
  • \$\begingroup\$ Thanks! I couldn't think of any application for two diodes with the same cathode (it seemed like you could just tie them together at the anode) but I guess that wouldn't be true \$\endgroup\$ – Trevor Gross Jan 26 '16 at 15:55
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    \$\begingroup\$ @nraynaud: Or clamping multiple inputs. \$\endgroup\$ – Ignacio Vazquez-Abrams Jan 26 '16 at 15:55

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