MB4S Datasheet Doesn't Match Part Scribe

I’m experiencing some confusion with this component, the datasheet says the AC input is on pins 1 and 2 with DC out on 3 and 4, but the part scribe indicates DC output on pins 1 and 2. The components are not currently with me so I cannot simply apply power and see how it behaves.

Is the scribe on top of the part rotated 180 or am I missing something simple?


The MB4S is a fairly generic bridge rectifier part number available from multiple suppliers–are you certain that the part pictured and the datasheet referenced match?

I’ve asked our ON Semi product team to look into this. I’ll be in touch when I hear what they have to say. That said, Rick also has a point in that the device seems to be fairly simple according to the ON Semi datasheet. If this is from a different supplier, could simply be that the supplier rotated their silicon 180 and shifted their silkscreen to match.

It’s unclear if the component in the image is the same make that I had spec’d out on the BOM, I’m not sure where the fab house sourced their components from. I’ve requested they manually test it to see which orientation is correct. I figured all parts with the same part number would be identical regardless of the manufacturer, the more you know I suppose.

I’ll report back with the result if they’re able to test it.

Functionally it would be, the device does the same job with the same general pin configuration. It’s a bit odd to see the dimple on the wrong end, but I don’t believe that would impede the device’s function.

Looks to me like the little half-moon on the end of the package is somewhat arbitrary between vendors. However, the beveled edge seems to be consistently on the DC side, and non-beveled on the AC side.

Micro Commercial Components:
On Semi:


Looks like the bevel is the more reliable orientation mark. I did get the source of the components, https://lcsc.com/product-detail/Bridge-Rectifiers_Suzhou-Good-Ark-Elec-MB4S_C280383.html, which didn’t clear much up since the dimple is still not consistent between the datasheet and part image. I’m going to go with the bevel.

Does this issue arise often? I’ve never experienced this before.


I wasn’t specifically aware of this particular case, but this sort of thing does happen. Because different vendors have different packaging suppliers, you can’t rely on them to all be uniform. That is why it is critical to review datasheets before soldering down parts.

Another related problem one sees occasionally is with how parts are oriented in the tape pockets on tape-and-reel. There are often options of more than one orientation, and the default orientation may differ from one vendor to another on “industry standard” part numbers. The people running pick-and-place machines really have to be careful for that, and it is sometimes hard to find documentation about that.

P.S. I just looked at that link for your part made by “Good-Ark”. I don’t know about you, but in my experience, with the exception of welding equipment, the word “Ark” is never “Good” when dealing with electronics!