I just bought a few strips of apa104 leds, and I can’t seem to find a definitive answer on how much current a single pixel can draw on full white. Do the draw the same as a ws2812b? 60ma?
The LEDs used in the various packages are almost (or are) identical. What makes an APA different from a WS is the chip.
So yes, about 20mA per colour at flat-out white.
The APA104s, as far as I know, yes, they’re actually clones of WS2812Bs and should draw around 60mA per LED. APA102s are a different beast and the, uh, poorly-translated datasheet indicates they draw less (and that’s the assumption I’m working on for LEDstimator: https://appsto.re/us/AV6x4.i). If anyone has some empirical data they would like to share it’d be much appreciated.
My test rig of 4x APA102 pixels draws 168mA when all four are set to 100% white (0xff 0xff 0xff 0xff). It draws 4mA when all four are set to black (0xff 0x00 0x00 0x00).
I’ve never used APA104 pixels, however.
The current through the LED is controlled by the chip. They’re constant-current drivers, as is virtually every LED driver on the market.
See-also: why it’s annoyingly difficult to drive large lengths of common-anode strip with PWM.
@Luminous_Elements I’m not sure why you addressed that to me, I am not the one asking for enlightenment. (Yes, a “light” pun in an LED forum… Who knew?
Your first comment can be read to imply that it is the LED package that controls the current through the LED. Reading it again, it’s still ambiguous as to what point you’re trying to make. I just wanted to specify that it is the driver chip (whether APA or WS) that controls the current through the LED, and not some external factor.
(Although it’s likely a similarly-sized/priced diode will have an almost-identical current-to-brightness response).