Antenna and oscillator questions

[SamDeu]

Hi all!

Im still  new to this and I'm trying to help a friend with a PCB design. We are using the nrf52832 and recreating the design from the reference circuit given in the data sheet (as shown below). 

My first question is about the antenna, all the information I found online was too complicated for me to understand. I however decided to persist and designed a PCB with a AH316M245001-T Taiyo Yuden antenna connected after L1, this antenna is away from all the other components and not on the ground plane. I just wanted check if this was the right thing to do. Screen shot of PCB is attached below.

 

My second question is to do with X1, in the data sheet it recommends using XTAL SMD 2016 which has 4 pins. I was wondering which pins of the oscillator connect to XC1 and XC2 on the nrf52832. I found some conflicting information I hoping to get a straight answer.

Sorry if these are silly questions, I have never used this chip before and is proving to be quite a challenging project. Thank you in advance!

[Marjeris Romero]

Hi,

I am sorry for the late reply. Regarding the antenna. For chips antennas it's important that you follow the reference design for placement from the manufacturer. Here is the datasheet for the antenna, see under "Technical considerations">"Land pattern dimension examples and recommended antenna land pattern": http://www.farnell.com/datasheets/1918813.pdf

For AH316M:

What you need to do is to follow the dimentions and placement that are shown in that picture. See also that they include the footprint for a PI network matching (what they call "Land for matching circuit") which consists of 2 shunt components and one series component. Include this components as well so you can match your antenna to 50 ohms.

 

I was wondering which pins of the oscillator connect to XC1 and XC2 on the nrf52832

For this you need to look at the datasheet of the oscillator, each pins will be mark there. Which oscillator are you using? "XTAL SMD 2016" just refers to the type and dimentions recommended, you need to find a part that suits these recommendations, also for the load capacitance (Cl=8 pF) and tolerance (±40 ppm).

Best regards,

Marjeris