Suggestion Regarding nRF51822 Custom PCB Design

[Nazmus Sakib]

Hi all.

I am making a PCB for nRF51822. My PCB need is to talk with iPhone for BLE Proximity application. Also I need to control a LED from iPhone. And I need to get low power mode of the SOC to get a good battery (3V Coin Cell) life. Its my first work with nRF51 so little bit tensed about the design. Below are my ques and please apologize if my queries are silly.

-1. I'll use QFAA package of nRF51822. There are three reference design on datasheet. Internal LDO, 1.8V and DC/DC. For my project which reference design will be suitable?

-2. My PCB dimension needs to be too small. So I wanted to choose smaller package then SMT 0603 for R and C (like 0402 or 0202). Also I wanted to place the R and C as well as X-Tal on the bottom side of the nRF51 SoC to achieve smaller size. Please advise if there any issue with my planning.

-3. I need a good proximity range (few hundred feet under Line of sight) within my PCB and iPhone. I planned to use BAL-NRF01D3 Balun. But looking for a Chip antenna to get long proximity range. Can you please advise me a suitable chip antenna?

Thanks in advance.

Looking for your suggestion.

Regards.

[wlgrd]

Questions are never silly, but I guess you could get better help if you contact the Nordic Support team for this issue.

I don't know much about this, but I guess you will have problems putting high frequency components directly under your SoC. What R and C are you talking about, the ones going out to your antenna?

You should also specify which exact size you want to obtain. I would advise you to start with putting your battery beneath the Soc, and you should be able to design the rest of the circuit on the top-side of your board.