1 Reply Latest reply on Feb 22, 2016 9:04 AM by DiegoV_Intel

    Unexpected power from U1 on arduino breakout board

    volodya

      I just received a kit with Intel Edison and Arduino breakout board.

       

      I have first attempted to power it with a 9V 800mA  adapter. The board booted and I was able to flash the firmware, etc.

       

      However, I have noticed that the switching regulator was very hot - 56C. Then I checked the voltages and found that the bus marked as "5V" on the schematic actually had 6.45V.

       

      Since I needed 5V or below for my project, I tried to power the board using USB bus from a USB battery module. This works, the board boots but now the "5V" bus has only 4.5V. Checking the voltage at the USB port gives 4.88V - well within spec.

       

      All configuration is standard - I have not changed anything besides fastening Edison to the Arduino breakout board and applying power.

       

      Questions:

       

           * should U1 heat up that much ? It is above pain threshold (55C).

       

           * should we see 6.45V voltages on "5V" bus ? They seem to be close to tolerance for ICs on the board.

       

           * I originally though to use 12V power - this is within specs, but if this nudges 6.45V higher I am afraid some ICs can be damaged.

       

      Suggestions are welcome !

       

      thank you

       

      Vladimir Dergachev