The nice people at Allegro are sending me some samples of their LED driver (8621) and I was wondering if anyone's got any info/tips on how to integrate. As I understand this is what powers the ShiftBrite and it looks like there's a lot I can learn from this exercise.
All guidance/input appreciated.
regards,
-fs
It's pretty straightforward. Your main concern is heat; the regulators need to dissipate power in order to correctly control the LEDs. It's a surface mount QFN package, which means the thermal pad underneath the chip is smaller than the chip. I used a via under the chip to conduct heat to the other side of the PCB, to a large ground plane. You can also get some heat to travel through the PGND and LGND pins, since you can connect those to the thermal pad.
Another important consideration is power stability. I'd include a 10uF capacitor on the main LED power lines. With ShiftBrites, you sometimes have to add a capacitor to the chain, depending on the power supply and cable length.