Open edwardrossi opened 2 years ago
With the chip shortage, I'm not really seeing any good alternatives in the same package/pinout. If you're willing to modify the PCB design, you could look if you can find a 1117-style regulator (same size package, but different pinout). Or just find a suitable regulator >5V input, 3.3V output at >600mA and update the PCB for whatever package you can find in stock...
That AP2115R5-2.5TRG1 is not going to work though - it's a 2.5V regulator and also a different package (I didn't check size exactly but the pin spacing is different and it also requires connecting its EN pin); and the 3.3V version appears to be unavailable as well in any case...
If you can find AP7361C-33E-13, I believe that is a pin-compatible drop-in replacement, but also low availability...
In my experience with the SK6812 LEDs you can happily drive them from a 3.3V signal. The spec sheet says the V1H is 5V*0.7 = 3.5V) but in practice it switches just fine. The first SK9812 in chain increases the signal level to 5V for the next SK9812.
One thing I would suggest on the prototype board is to place a DNP resistor between LED_DATA_3v3 and LED_DATA_5v so one could choose to not populate the SN74 and try and drive the LEDs directly.
Also in my testing with SK6812 the bypass caps per LED aren't needed, if someone is trying to cut pennies from the BOM.
+1 on the Do Not Place. Not only does it offer more flexibility, it can also help with debugging and repairs, because it exposes pads :)
In my locale (Australia) Mouser has stock for all components bar two: U6 AP2114HA-3.3TRG1 and U7 SN74LV1T34DBVR.
These components look to be sold out globally with a lead time of at least two and nine months respectively.
I'm wondering whether AP2115R5-2.5TRG1 might be a compatible replacement for AP2114HA-3.3TRG1 as it looks like mouser has a 20 day lead time, as oppose to 9 months for AP2114HA-3.3TRG1. The package and specs look almost identical.