I have my redesigned board reflowed here and I’m troubleshooting an issue… The most obvious symptom is the 3.3v power bus is sitting at 0.840 volts and the 500ma LDO regulator gets warm, so it’s obviously a power consumption issue. I’ve triple checked with a magnifier I don’t have any solder bridges on the SC20100S or other chips, so that isn’t the problem. I also re-checked I have the right pins connected to power and ground, both by referencing the GHI pinout PDF and the processor datasheet. I know this chipset takes more power than the older G80 chip, but I should still be within within spec. Here are my 3.3v power consumers that are of any significance:
SC20100S - typical while executing code = 226ma, 25*C max = 348ma (per datasheet @ 480mhz, all peripherals on)
RN4678 bluetooth module = max 25ma
WinBond flash = 25ma max (<1ma in standby)
My current consumption should be ~400ma worst case, but typically around 250ma… So I may be on the edge and should probably go to a 1a regulator, but I don’t think the lack of power output from the regulator here is the problem… thoughts?