Bluetooth Low Energy Module - Single Mode [just Bluetooth Low Energy communication protocol] - Based on Nordic bluetooth chip nRF8001 - Schematics based on the design reference from Nordic nRF8001 with internal DC/DC converter disabled. - The internal low frequency (32.678kHz) crystal oscillator is used (optionally you can add and external crystal oscillator if high accuracy is needed, please check in nRF8001 documentation); - The 50ohms impedance matching from the chip pins to the antenna was made using analog components based on Nordic design reference, but optionally you can use the Johanson 2450BM14A0002 Balun. PCB considerations: - 2 layers board - 10 mils trace width for power and antenna traces; - 6 mils for all other traces; - 6 mils minimum clearance for copper to copper; - Via with 13 mils hole and 7 mils annular ring; - All vias below components have solder mask to prevent short circuit when reflowing/soldering SMD components; - nRF footprint based on Nordic reference design and documentation; Antenna considerations: - Be aware that the chip antenna datasheet information was measured using a specific ground plane size and shape, in other words, the ground plane area total area and shape modifies the antenna performance. Therefore, after integrating this PCB to your own design consider building a prototype to test antenna performance. - It is important to keep the exact size of the antenna keepout and feed components positioning/distance, please check the chip antenna datasheet; - Alternatively, you can change the chip antenna to whatever you want/need (for instance - PCB pattern antenna or dipole antenna), just remember to match the impedances from the chip pins to the antenna, that usually is 50ohms Technical documents/information about the nRF8001: http://www.nordicsemi.com/eng/Products/Bluetooth-R-low-energy/nRF8001