Unable to connect to blank nRF9151-LACA on custom board using nRF9151 DK external debugger

RE: Unable to connect to blank nRF9151-LACA on custom board using nRF9151 DK external debugger

Simon D-M — Fri, 19 Jun 2026 10:48:58 GMT

Hi,

There is already a warning that the default voltage output of the board is 1.8V.

It is recommended to power the external board separately from the DK. The voltage of the SWD interface on the external board must match that of the DK. The default voltage is 1.8 V.

And the board debugger does not only support nRF91. It can actually debug almost any chip that has as SWD interface. So we don't want to say that the user should use a higher voltage as it might not fit other chips.

I hope you understand my point. If you have further question, feel free to ask.

Best regards,

Simon

RE: Unable to connect to blank nRF9151-LACA on custom board using nRF9151 DK external debugger

Plakkies — Fri, 19 Jun 2026 06:46:45 GMT

Thank you so much for the info. Its programming now. It would be great if someone would add this to the below document.
docs.nordicsemi.com/.../ext_programming_support_p20.html

RE: Unable to connect to blank nRF9151-LACA on custom board using nRF9151 DK external debugger

Simon D-M — Thu, 18 Jun 2026 11:33:52 GMT

Hi,

The nRF9151 requires a VDD voltage from 3.0V to 5.5V. So the 1.8V is not enough to power the chip (link).

The VDD voltage range is different from VDD_GPIO that requires a voltage from 1.7V to 3.6V. But this is to power the GPIOs (link).

Can you please try to adjust the voltage on VDD and try again?

Best regards,

Simon