ledrgb
I have a project that has 48 various lengths of WS2812B RGB tape strips. All 12V.
Here is a link to the tape i am using. datasheet
I seem to have a lot of flickering at the ends and the occasional flash or artifact when running animations.
I am not sure what the issue is, i cant tell if it is voltage or signal. What can i do to determine where the problem is?
Does this sound like common issues with this tape?
Thanks,
Try using a PT78ST106V-ND Through hole SIP-3 Module it's a 1" x 1" three terminal integrated switching regulator (ISR) which has internal short circuit and over-temperature protection as well as good line and load regulation.
http://www.digikey.com/product-detail/en/PT78ST106V/PT78ST106V-ND/323539
Number of Outputs 1
Voltage - Input (Min) 10V
Voltage - Input (Max) 38V
Voltage - Output 1 6V
Voltage - Output 2 -
Voltage - Output 3 -
Current - Output (Max) 1.5A
Here's the PDF http://www.ti.com/lit/ds/slts059a/slts059a.pdf
The FET you link to is not suitable for your application. Taking a look at the "typical characteristics" table, we see this:
Vgs(th) is listed as between 2 and 4 volts - already it could be higher than our supply voltage, but not especially the "conditions" column on the right: the specification is given with only 250 microamps of current. Your LEDs, presumably, will draw a lot more than that.
To figure out if the FET is suitable, you need to know how much current you plan to draw, then look for the graph plotting "typical output characteristics":
Look for a line corresponding to the gate voltage you plan to use - in this case, there isn't one low enough - and look for where the curve flattens out. If that's at a current level greater than the amount of current you need to supply, you're good. Alternately, look at the "typical transfer characteristics":
This plots maximum current as a function of gate voltage, so you can trace a line from your MCU's gate voltage - 3.3 volts - to determine what the maximum current level at that gate voltage will be. Again, in this case, the plot doesn't actually go low enough to evaluate that on this particular FET.
Keep looking - there are FETs that meet your requirements - and remember that everything depends on how much current you plan to conduct.
Best Answer
Confirmed. I had a similar flickering issue with 5V addressable LEDs with about 2.5-3 meters of cable. Even if the all connections were insulated, holding the LED strip in my hand provided a lot of capacity through the ground connection to eliminate the RF noise. So adding one simple ferrite clamp solved this issue instantly.