Need to bridge SB12 to power eval board with external supply

RE: Need to bridge SB12 to power eval board with external supply

Torsten Robitzki — Fri, 24 Apr 2020 07:40:21 GMT

I've checked that with the second board I have and there, powering the board externally works without closing the solder bridge. For the first board I had to close the solder bridge to see any voltage at TP14. Maybe the other diode was broken or what ever :-)

Anyway, thanks for taking the time to look into this!

best regards,

Torsten

RE: Need to bridge SB12 to power eval board with external supply

Kenneth — Thu, 23 Apr 2020 13:35:26 GMT

Hi,

I have received more information about the circuitry, this should work without the diode as described in the attachment.

devzone.nordicsemi.com/.../pca10040_5F00_schematic_5F00_sheet7_5F00_battery_5F00_power_2D00_up.pdf

Best regards,
Kenneth

RE: Need to bridge SB12 to power eval board with external supply

Torsten Robitzki — Thu, 23 Apr 2020 11:48:25 GMT

Hi Kenneth,

thanks for looking into that. But in this case, one would definitively have to close the solder bridge to power the board externally. Would have been easier (from a user perspective) to leave the solder bridge out (aka close it).

best regards,

Torsten

RE: Need to bridge SB12 to power eval board with external supply

Kenneth — Thu, 23 Apr 2020 11:40:52 GMT

I can check with the person that have done the layout, however he is currently out of office. I will update when I hear back. It might be that they have done it this way to avoid the diode voltage drop when using external power.

Kenneth