Going from nRF52840 DK to PCB

[JSCBLOG]

Hello,

I've been playing around with the nRF52840 DK board and I want to make what I've been working on, into a PCB. Following the link below I've got the Altium files for the nRF52840 IC, by downloading the 1.1 QIAA Layout and BOM resources. There are a few questions I have about this, listed below.

https://www.nordicsemi.com/Products/nRF52840/Compatible-downloads#infotabs

1) I see that there are some configurations, which are shown in the infocenter. For my design, I'm just using a 3.3V battery to power a simple BLE circuit. I'm not using NFC or USB communication, so does this mean I should use the configuration 6 PCB?

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf52840%2Fref_circuitry.html

2) To power the circuit I am using a coin cell battery like a CR2032. The reference designs don't have any circuitry to do with power, so would I just need to design a circuit to power the board and connect the output to VDD_nRF?

3) How would I program the board? I assume I can connect an SWD programmer directly to the pins and do it that way. With the default PCB is there any additional circuitry I need to add or can I just use a header pin to directly connect the programmer to the board?

Kind regards,

J

[Bendik Heiskel]

Hello, 

1) I see that there are some configurations, which are shown in the infocenter. For my design, I'm just using a 3.3V battery to power a simple BLE circuit. I'm not using NFC or USB communication, so does this mean I should use the configuration 6 PCB?

 The configurations does not show all the possible combinations of features. Configuration 6 can be used if you do not want to use the internal DCDC converter. Configuration 5 can be modified to work in your application by removing the NFC part and copying the USB configuration from configuration 6, this will give the option to use the DCDC converter. By combining the different configuration any possible combination of features can be used.

   

2) To power the circuit I am using a coin cell battery like a CR2032. The reference designs don't have any circuitry to do with power, so would I just need to design a circuit to power the board and connect the output to VDD_nRF?

Yes, in most cases an power supply circuitry must be implemented separately and connected to the VDD_nRF net. In your case this is not required, seeing as the chip can be supplied from 1.7-3.6V through the VDD pins. This means that a coin cell battery supplying 3.3V can be directly connected to VDD without any external regulators needed. More information about the power supply and internal regulators can be found in the product specifications.

 

3) How would I program the board? I assume I can connect an SWD programmer directly to the pins and do it that way. With the default PCB is there any additional circuitry I need to add or can I just use a header pin to directly connect the programmer to the board?

 No additional circuitry is needed to program the board. The only connections needed is VDD, GND, SWDIO and SWDCLK.

 

Best regards,

Bendik Heiskel