Schematic for custom PCB

[Ehsan]

Hi,

I am designing a custom PCB using the nRF51422 chip. I have a program that I developed on the nRF51-DK. The program reads the capacitance value of a proximity sensor at one of the analogue input pins and then the RTT is used for display this value on a terminal program. I want to do the same with my custom PCB and the design I have is attached. Is this design sufficient for this function or do I need to make any alterations? Thanks.

Schematic.PNG

[bjorn-spockeli]

Hi Ehsan,

You're missing several mandatory components like the 16MHz crystal, the DEC2 capacitor(C10) and the C9 capacitor between VSS and AVDD. Furthermore, adding a pulldown resistor to the SWCLK line is not a very good idea.

You should copy the reference circuitry in the nRF51422 Product Specification, found here. You will find the referance circuitry in Section 11: Reference Circuitry.

Bjørn

[Ehsan]

Hi,

I have redesigned my schematic to match the reference layout. I have attached the design in my original question. I am not planning on using the ANT system and hence, I have not included it. Do I still need to connect a capacitor to the VDD_PA pin? I would be grateful if you could let me know if my design is correct. Thanks.

[bjorn-spockeli]

Do you mean that you are not going to use the Radio on the nRF51 at all? Or do you mean that you're not going to use the ANT protocol support? If that is the case then you should go for the nRF51822 which only support BLE.

[Ehsan]

I am planning on using the bluetooth capacibities of the chip later on. I won't be using the ANT protocol or any other radio comms. Do I need the VDD_PA pin connection?

[bjorn-spockeli]

If you plan on using the nRF51422 for BLE then you need to add all the components connected to ANT1, ANT2 and VDD_PA.