Regarding nRF51822 RF range using balun and minimum layers required for balun

[Shahid Ali Nadaf]

Hi,

I am doing a BLE based project using NRF51822. I am asked to build a 2 layer board.

According to the reference schematic BALF-NRF01D3 has been used with WLCSP package. Since this balun is difficult to mount at my expense can you suggest me any other balun with QFAA package and similar properties and range.

I read the following post devzone.nordicsemi.com/.../

But here i am not able to understand what range can i expect by using nRF51822/422 QFN and discrete components for matching(pi network).

nRF51822/422 QFN - www.johansontechnology.com/integrated-passives/chipset-specific-ipc/nordic-semiconductor.html#.VOW78pjuKRt

Another Question:- Can balun be mounted on 2 layer board?? Or a 4 layer board is required to mount a balun??

Looking forward your suggestion.

[FormerMember]

I would recommend you to read the blog post "General PCB design guidelines for nRF51", it should answer most of your questions.

BALF-NRF01D3 should not be used with the WLCSP version, it should be used with the QFN version of nRF51822.

[Shahid Ali Nadaf]

Hi,

Thanks for your reply. It has helped me a lot.

As is said i want a 2 layer board, But Nordic has provided a 4 layer gerber files with BALF-NRF01D3 QFN package.

is it possible to design 2 layer board with nRF 51822, BALF-NRF01D3 QFN package and chip antenna?? Or a 4 layer board is required for this Balun??

Looking forward for your reply.

[Shahid Ali Nadaf]

Hi,

I did not find the 2 layer board for nRF 51822 QFN with Balun BALF-NRF01D3 QFN package. I checked on the Nordic website even there they have provided 4 layer board design.

Now if i design a 2 layer board on my own, can i use the same track width for the RF section as provided by the 4 layer Design by Nordic?? Or should i follow any other track width and track length standards?

Won't the impedence matching of my 2 layer board get affected if i use the track length and track width given by Nordic for 4 layer design?

Looking forward for your reply.