low power wearable electronics.

[LoPow@]

I have designed single layer pcb for the first time using kiCAD software for  low power (1-5mW) wearable electronics using nRF52840,one accelerometer sensor i.e.BMA400,one recommended antenna(AN91445) and one 2x5 programming port. Please refer to the attached the document. Please suggest any correction and a suitable program/code so that we can test it using ARM Segger Studio.Low power basic Reference.pdfLow power basic1.0.csv

[JONATHAN LL]

HI,

There are a couple of big issues here that will cause problems for the operation of the nRF52840 and they can all be solved with adding a second layer to the PCB. The RF capabilities of the device will be poor. 

Is there a specific reason to why you only want to use a single layer?

Regards,
Jonathan

[LoPow@]

The main reason is cost. If we used multiple layer pcb then we have to add vias for connection and this will increase the cost of fabrication for revision one. Another is, for early fabrication we used single layer pcb.

[Priyanka]

Hi,

Jonathan is on leave and I will be taking over the case. Please expect a slight delay as it is the vacation period this week and we are a bit understaffed at the moment. Thank you for your patience.

-Priyanka

[JONATHAN LL]

Hi LoPow@ ,
The cost saving is not worth it in this case. The performance will be terrible and not representative of a two(multi) layered design so it will not be representable of the final product. 

So this is not recommended. Pleas follow the reference layout to achieve good results. Failing to follow the design guidelines can result in a non working device. 

The center pad of the SoC needs to be connected to the rest of the ground for the radio to work as intended. 

Also the antenna you have used is degined to have a ground plane also. So it might not work at all as it is in your current desing.


https://www.infineon.com/dgdl/Infineon-AN91445_Antenna_Design_and_RF_Layout_Guidelines-ApplicationNotes-v09_00-EN.pdf?fileId=8ac78c8c7cdc391c017d073e054f6227 

Regards,
Jonathan

[LoPow@]

This is the updated version of Low Power Wearable Electronics.Please check it and suggest corrections....