I have created the PCB design to build large 7 segment display based on WS2812 leds (design attached). But now I am looking at the datasheet and I see capacitors for individual leds.
The question is this PCB as is would work if I add one capacitor between the + and - pins powering that board.
Can't you mount a capacitor on each WS2812 between GND and +V?
This capacitor is not essential for operation, but it avoids problems.
It's a decoupling capacitor.
In electronics, a decoupling capacitor is a capacitor used to decouple (i.e. prevent electrical energy from transferring to) one part of a circuit from another. Noise caused by other circuit elements is shunted through the capacitor, reducing its effect on the rest of the circuit.
I think I will have to. I am not very experienced with SMD soldering and adding 14 SMD capacitors means that with 28 components to mount I am afarid that I would mess something up.
Also I am planning to get those capacitors from online store and I am checking some photos and I cannot see how on SMD capacitor the minus or the plus side is marked. How are they normally marked on a tiny part like that?
SMD capacitors of this value are normally not polarized.
In other words, it can be mounted in any position.
Value 104 = 100,000 pF or 0,1 uF.
or ceramic:
Ok. So I guess I could make my life easier by adding classic capacitors into my design. Then I can solder the leds on and see if the design works without those capacitors with the option of adding then in case I need them
It is most likely you will find you need at least some of them, and that performance will be unpredictable if you install "just enough", due to factors you can't even measure. If it were me, I'd start by soldering in every 4th one, see how well it works, and if there's any doubt at all, put in every second one, and finish by filling the gaps.
But in one way, it would be better if you just soldered them all - if you're going to stay in the electronics game you'll need that skillset, so why not get the practice early?
+1.
@Dziubym it's not like there is some global conspiracy wherein the industry is needlessly recommending you put this part here or there.
A good habit is to check the data sheet and follow the advice there for components and PCB layout as closely as possible. As well as the other things like maximum currents and voltages and stuff.
You will have no sympathy if you build it, it works poorly and you have to say you left off a few components you felt were too much trouble.
a7
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