nRF52840 DK - Power Supply

RE: nRF52840 DK - Power Supply

Nikosant03 — Mon, 09 Mar 2020 15:42:14 GMT

Actually I have one more question. Can I supply the board from the VDD pins provided by P1 header?

RE: nRF52840 DK - Power Supply

Nikosant03 — Mon, 09 Mar 2020 15:38:44 GMT

Thank you for your assistance!!

RE: nRF52840 DK - Power Supply

ketiljo — Mon, 09 Mar 2020 15:11:12 GMT

[quote user="Nikosant03"]Both programming and debugging of the firmware on nRF52840 SoC is done through the J2 USB connector and when the J2 connector is used the board is supplied from the 5V domain?[/quote]

Yes, the debugger is connected to J2

[quote user="Nikosant03"]In order to power supply the nRF52840 SoC from the J3 I must toggle SW9 to USB isn’t it? I connect USB to J3 and toggle the switch to USB position, but the board is completely inactive. What is the purpose of J3 and how could I use it?[/quote]

If you want to use the USB interface on the nRF52840, you must use J3. The switch J3 should be set to the USB position of you want the nRF52840 to be supplied from J3.

From the PS: The nRF52840 System on Chip (SoC) has a high voltage buck regulator that can support up to 5 V input. In the VDD position, the SoC is powered either from the on-board buck regulator, coin cell battery, or external supply (P21). In the Li-Po position, the high voltage regulator of the SoC is supplied directly from the Li-Po battery connectors (J6 or P27). In the USB position, the USB high voltage regulator gets power from the nRF52840 USB connector (J3).

[quote user="Nikosant03"] want for example to supply the board with either 3.3V or 1.8V and measure the current consumption of nRF52840 SoC only. In that case, I must toggle the SW6 to nRF ONLY position and use the external power supply which is unregulated to supply either 3.3V or 1.8V. Ensure that the high voltage regulator is inactive meaning that VBUS, VBUS_nRF, Vli-Ion and VIN3-5V signals are low. If I want to include external's memory power consumption to the nRF52840 current measurement I must supply the external memory from VDD_nRF (short SB18 to connect memory power supply to VDD_nRF. Is this procedure correct?[/quote]

Yes, that's correct.

[quote user="Nikosant03"]If the boost regulator (high voltage regulator U12) is used, then the coin cell battery and the external power supply are ignored?[/quote]

Yes. The regulator U12 is supplied from VBUS, Li-ion input or the VIN, see the PS

RE: nRF52840 DK - Power Supply

Nikosant03 — Mon, 09 Mar 2020 11:46:19 GMT

Thanks for your reply. I have some questions so far:

Both programming and debugging of the firmware on nRF52840 SoC is done through the J2 USB connector and when the J2 connector is used the board is supplied from the 5V domain?

In order to power supply the nRF52840 SoC from the J3 I must toggle SW9 to USB isn’t it? I connect USB to J3 and toggle the switch to USB position, but the board is completely inactive. What is the purpose of J3 and how could I use it?

I want for example to supply the board with either 3.3V or 1.8V and measure the current consumption of nRF52840 SoC only. In that case, I must toggle the SW6 to nRF ONLY position and use the external power supply which is unregulated to supply either 3.3V or 1.8V. Ensure that the high voltage regulator is inactive meaning that VBUS, VBUS_nRF, Vli-Ion and VIN3-5V signals are low. If I want to include external's memory power consumption to the nRF52840 current measurement I must supply the external memory from VDD_nRF (short SB18 to connect memory power supply to VDD_nRF. Is this procedure correct?

If the boost regulator (high voltage regulator U12) is used, then the coin cell battery and the external power supply are ignored?

Thanks in advance

RE: nRF52840 DK - Power Supply

ketiljo — Fri, 06 Mar 2020 13:18:49 GMT

That's normal. The USB connection to the nRF52840 is the other USB connector.

If you use J2, you will power the board from the USB connector so you can't use that together with the battery. Only the nRF USB can be used with the battery. But in that case, you will only have access to the nRF52840 USB interface and not the debugger

RE: nRF52840 DK - Power Supply

Nikosant03 — Fri, 06 Mar 2020 06:41:10 GMT

Hi ketiljo and thank you for your prompt response. I have read that in order to power up the board from the USB the switch (SW9) must be set to USB position. However, at the moment I have set the switch to VDD and the board works normally from the USB (J2), but it shouldn't work isn't it? So I am a bit confused...

RE: nRF52840 DK - Power Supply

ketiljo — Thu, 05 Mar 2020 14:27:20 GMT

The USB connection is not related to the power supply. So you can have the USB connection up while you power the device from another power source. If you want to power if from the USB connector, you must set the switch to USB.

See the HW description at_ infocenter.nordicsemi.com/.../hw_power_supply.html