The APA102 datasheet (https://cpldcpu.files.wordpress.com/2014/08/apa-102c-super-led-specifications-2014-en.pdf) specifies a power consumption of “0.2W (MAX 1W)”.
Well, which is it? 0.2W or 1W? Does that mean a max draw of 1W each on full-white, but 0.2W “dark” draw? Has anyone got a bunch (at least a hundred) of them and hooked them up to an ammeter to confirm either of these figures empirically?
I have no idea about the power draw, but I did post on Adafruit to learn if the apa102 was brighter than the apa102c. They, Phil, said that they appeared to have equal light output.
Disappointing… I’m always looking for more light.
Those figures are probably correct. 0.2W with LEDs off, thus the driver chip uses about 40mA idle. And the whole thing uses 1W (200mA) when all LEDs are at full output. 200mA (full) - 40mA (idle) divided by 3 (for each LED) gives an LED drive current of about 53mA each.
The difference between the C and the non-C version appears to be that the C version has very little internal heat dissipation. So the C is likely to have a much shorter life if the LEDs are driven hard (bright). 1W in 5mm2 is pretty difficult to dissipate when mounted on a thermal insulator like a plastic ribbon or fibreglass PCB in air. And this will affect junction and substrate temperatures.
I thought they had the same current as WS2812? 60mA per pixel?
40mA idle sounds way too high to me @Adam_Sharp , do you have any empirical data? Through the discussion of FastLED’s power output clipping feature we were talking more like 20mA per channel (i.e., 60mA per LED full-white), with 1mA per LED “dark draw”.
Ah, even less than 20mA per channel (from FastLED/power_mgt.cpp):
static const uint8_t gRed_mW = 16 * 5; // 16mA @ 5v = 80mW
static const uint8_t gGreen_mW = 11 * 5; // 11mA @ 5v = 55mW
static const uint8_t gBlue_mW = 15 * 5; // 15mA @ 5v = 75mW
static const uint8_t gDark_mW = 1 * 5; // 1mA @ 5v = 5mW
I believe these were measured from actual WS2812B chips; so I guess my question is has anyone verified APA102Cs are the same, because the datasheets appear to say they’re different.
With 101 APA102s and an Adafruit Pro Trinket, I was seeing .12 amps at idle (Brightness at 0 for all LEDs).
I’m running a strip of 144 APA-102C and a Teensy 3.1 off a 5V 4A power supply. According to my Kill-A-Watt, they’re pulling 11.5W, .17A at 123V (full brightness, all white). I know those numbers don’t add up according to Ohm’s law, just reporting what I’m seeing. I don’t have any other way of measuring the current draw.