The award winning nRF51822 is now available as an ultra-thin Chip Scale Package) CSP variant. Measuring just 3.38mm x 3.38mm and with a height profile (including ball grid array) of just 0.35mm it is tiny, tiny enough to fulfill the requirements of the smartcard industry for example.
As the world of Bluetooth Smart connectivity broadens ever further so do the demands placed on PCB real estate designers. Everything is getting smaller, ICs, supporting components and the overall designs are cramming more into less.
For the smartcard industry there are absolute demands on size so that cards can fit reading machines etc. In wearables every square mm of PCB space it at a premium and so all savings no matter how trivial they may immediately seem are a boon.
Next generation wearables
Wearables is a pretty broad catch-all description for a surprisingly wide range of applications. When one thinks of this market the likes of FitBit and Jawbone, Polar and Pebble watches immediately spring to mind, but I can assure you that’s just one sub-segment of the wearables pie.
We are seeing notification rings, jewelry and even moves into embedded electronic apparel. These applications are particularly sensitive to size, most especially the height of the electronics. At 0.35mm the classic nRF51822 can be realistically embedded into fabrics even and this is opening up very exciting new wearables territory.
It's still the classic nRF51822
The thin CSP variant is the same SoC without compromise it has 256kB of flash and 32kB of RAM on chip. It still supports the S130 multi-role concurrent operation SoftDevice, and the nRF5 SDKs.
When you know you need an nRF51822, you’ve just got to go smaller, this is your device of choice.
More on nRF51822 Bluetooth Smart SoC
The dimensions for different nRF51822 variants are presented in the nRF51822 PS 3.2 document, chapter 9 about "Mechanical Specification". Thinnest QFN is maximum 0.9mm and thinnest "original" WLCSP is maximum 0.55mm. The ultra-thin CTAC variant is maximum 0.41mm, typically 0.35mm.
What is the height of the smallest "original" WLCSP and QFN variants of the nRF51822?