A diode can be put on a a PCB in one of two ways. It’s only got two pins (usually — see, I already have a caveat). I’ve written about them a few times before. I’ve got a sampling of those posts here. But first,
Good marking:
Bad marking:
The diode schematic symbol is always a good choice. If there isn’t room for that, “A” for anode or “K” for cathode work well too. Why “K”, and not “C”, you may ask? Because “K” kan’t be konfused with a capacitor.
- Why not a plus sign? Because, while you’ll usually find the anode on the positive side of things, there are plenty of cases where you won’t. Read about that here.
- Why not a negative sign? The same reason. Read a bit more here.
- Why are LEDs an extra pain? Check this post out.
- Why does THIS happen to diodes? Why? Why? Why?
- Why can’t diode manufacturers follow standards?
Okay. Enough ranting for now. Just use the diode schematic symbol, “A”, for anode, or “K”, for cathode; and always look at the data sheet for the exact part number.
Duane Benson
1 cricket per chip