feeding on external power supply and USB simultaneously

[fatemeh ghasemi]

I am working with nRF 52832 platform and I soldered SB12 and cut SB10 because I wanted to feed from the external power supply and with this situation I can not connect to the platform and jlink does not appear. if I solder SB10 and cut SB12, I can connect to the platform and run my application but the problem is with this set up I am feeding on external power supply and USB both. Is there any solution that I can connect to my platform without feeding on USB?

[Amanda Hsieh]

Hi, 

Note that while SB12 is shorted, the dev kit must not be powered from USB if there is a battery or external supply connected because the protection diode has been bypassed. Also, note that the allowed voltage level on external supply pins is 1.7 V - 3.6 V.

with this set up I am feeding on external power supply and USB both.

Note: Connect only one power source at the time. Shorting the solder bridges removes the reverse voltage protection.

Is there any solution that I can connect to my platform without feeding on USB?

You can short SB10 to use a coin cell battery on the nRF52 DK.

-Amanda H.