So, I bought Osram 0805 SMD LEDs in red, green, and orange.
I am populating a board with them now, but thought I would test the polarity of them first.
I discovered that for some reason, the Hyper red LEDs are marked with the dot on the anode, but the rest are marked with the dot on the cathode.
If I wouldn't have tested, all of the red LEDs would have been populated backwards.
http://www.mouser.com/Optoelectronics/LED-Emitters/Standard-LEDs-SMD/_/N-ec21j?P=1yzvlvb&Keyword=OSRAM&FS=TrueIn the Osram 0805 LEDs above on mouser, only the Hyper Red is backwards from the rest.
Is there some manufacturing/logistical reason to mark LED polarity in an inverse fashion?
Yes, this information is in the datasheet:
![](https://dl.dropboxusercontent.com/s/5yjzfccgl1x31bj/OSRAM_LHR974.png)
![](https://dl.dropboxusercontent.com/s/km13m6tznvk187f/OSRAM_LSR976.png)