https://devzone.nordicsemi.com/f/nordic-q-a/82516/nrf52-dk-pca10056-swd-connection-power-questionsP19 (Debug OUT Connector) on the nRF52840 BLE RF Development Board, PCA10056 (Dev Board) provides the ability to program a nRF52840 BLE board (BLE Board). Questions: 1. Is SB47 open or shorted by default? 2. Does EXT_VTG provide the means toen-USTelligent Community 13Wed, 08 Dec 2021 15:14:22 GMThttps://devzone.nordicsemi.com/thread/342576?ContentTypeID=1Wed, 08 Dec 2021 15:14:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0a333d43-64c1-41bc-8662-1eb7b0dcae39JONATHAN LL<p>Hi,<br /><br /></p> [quote user=""]1.&nbsp; Is SB47 open or shorted by default?[/quote] <p>Open by default:&nbsp;<a href="https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/solder_bridge.html?cp=4_0_4_7_12">https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/solder_bridge.html?cp=4_0_4_7_12</a>&nbsp;<br /><br /><br /></p> [quote user=""]2.&nbsp; Does EXT_VTG provide the means to detect if SB47 is shorted?[/quote] <p>No<br /><br /></p> [quote user=""]3.&nbsp; There are no I/O buffers for the signals on P19 on the Dev Board.&nbsp; If SB47 is open and the battery is not plugged in on the BLE&nbsp;Board or if the battery has run down to &lt; 2.9V, can signals on P19 from the Dev Board destroy the nRF52840 on the BLE Board (the signal levels on the BLE Board would be above VCC+0.3V).[/quote] <p>No, the board being programmed will be fine.&nbsp;<br /><br /><br />You can download the HW files for the DK here:<a href="https://www.nordicsemi.com/Products/Development-hardware/nRF52840-DK/Download?lang=en#infotabs">nRF52840 DK - Downloads - nordicsemi.com<br /><br />R</a>egards,<br />Jonathan</p><div style="clear:both;"></div>