An update on the 4x4x4 RGB Cubes.
The charliecubes seem to be working great. I have built a couple, and have been running them 24/7 on 5 volts via USB. I have also run them via the Vin with 18v, and they work fine, but the chip gets warm, so I went back to 5v.
The more proper cubes are still under development, one uses TLC5490, and the other uses shift registers and resistors. I built a 48 bit shifter for the anodes, and am using 2 shift registers to sink the 4 planes. I think I need almost 1 amp, and 2 shift registers wont be enough for that probably, so I may need to modify it.
I have a few ULN 2003a chips, and I had thought they would work for sourcing, but that may not be the best solution.
I have been investigating using p-channel and n-channel mosfets. There are a lot of them, and I dont know which ones would be appropriate. It seems the ones in the smaller packages are too small (1/4 amp), and the bigger packages are way bigger than my needs (4 amp).
What are good ways of supplying sink/source to the planes? Is one way vastly superior to another?
Another consideration is circuit board space, im using very small boards with little space, so space is as much consideration as cost (ideally both would be small.)
Shift registers, mosfets, darlington arrays are what I have been looking at, but maybe I should look at other options too?