Hi, I have the very same problem =( I am developing a car diagnostic system that connects with the car ECU. Thus I take power from the OBD connector which is 13-14 Volts. Every time I start up, the DUE hangs then it is absolutely reliable as soon as I press RESET button. This is very annoying. The TLC7705IP could be a solution even though I do not have much space left on the shield. I use the 12V power source (car power reduced with a couple of diodes) to power the DUE and I have a stabilization circuit (switching to 5V + linear to 3.3V) to power the 5" TFT display. I made this to avoid high current to pass through the Arduino DUE board. Would it be better to use the 5V pin on the Arduino to power the TLC7705IP or the external switching circuit?
Thanks in advance,
Luca72