ti 公司的cc8520 purepath無線平臺,是高性價比和低功耗的解決方案,最適合用于高質量數字音頻的無線傳輸. cc8520內置了無線音頻傳輸協議,能控制所選擇的外接音頻設備,支持兩個音頻通路,空中數據速率5mbps,可編輸出功率高達+3.5dbm,接手靈敏度-83dbm,音頻延遲低到20ms,適用于多種無線電頻率規范: etsi en 300 328 和en 300 440 class 2 (歐洲), fcc cfr47 part 15 (美國)以及arib std-t66 (日本). cc8520主要用在無線高質量數字音頻,無線點對點音頻鏈接,無線耳機和無線揚聲器.本文介紹cc8520主要特性, 應用電路和cc85xxem參考設計電路圖以及材料清單(bom).

the purepath™ wireless platform is a cost-effective and low-power solution optimized for wireless transmission of high-quality digital audio.

the cc8520 includes a robust built-in wireless audio transmission protocol and can control selected external audio devices. utilizing numerous coexistence mechanisms allows the cc8520 to avoid interfering with, or being interfered by other 2.4 ghz radio systems. the cc8520, which supports 2 audio channels, is the first device in the purepath™ wireless platform.

the cc8520 operates autonomously, and can be used with or without an external mcu. an external host processor can be connected through spi and control some aspects of its operation. the cc8520 interfaces easily with other ti audio ics and dsps (using i2s and dsp/tdm interfaces).

cc8520主要特性:

built-in audio protocol

- cd-quality uncompressed audio

- excellent robustness and co-existence through multiple techniques

- adaptive frequency hopping

- forward error correction

- buffering and retransmission

- error concealment

- optional high quality audio compression external system

- seamless connection and control of selected ti audio codecs, dacs/adcs and digital audio amplifiers using i2s and i2c

- hid functions like power control, binding, volume control, audio channel selection can be mapped to i/os

- rohs compliant 6mm x 6mm qfn-40 package rf section

- 5 mbps over-the-air data rate

- bandwidth-efficient modulation format

- excellent link budget with programmable output power up to +3.5 dbm and -83 dbm sensitivity

- seamless support for cc2590 range extender (+11dbm output power, -86dbm sensitivity)

- suited for systems targeting compliance with worldwide radio frequency regulations: etsi en 300 328 and en 300 440 class 2 (europe), fcc cfr47 part 15 (us) and arib std-t66 (japan)digital audio support

- digital i2s audio interface supports 1 or 2 audio channels at sample rates of 32,40.275, 44.1 and 48 khz, and supports 16 bit word-widths

- audio latency down to 20 ms

- data side-channel allows data to be sent alongside the audio between external host controllers development tools

- pc-based purepath™ wireless configurator (ppw configurator) for cc8520 configuration

- cc8520 user’s guide

- cc85xxdk audio development kit

- no software development needed

cc8520 應用:

- wireless high-quality digital audio

- wireless point-to-point audio link

- wireless headphones

- wireless loudspeakers

圖1.cc8520應用電路

cc85xxem參考設計

cc85xxem reference design contains schematics and layout files for the cc85xxem module used in the purepath wireless cc85xxdk development kit. the reference design demonstrates good techniques for cc85xx decoupling and rf layout. for optimum rf performance, these parts should be copied accurately. this is a 4-layer reference design with a discrete balun and two antenna options: either an sma antenna connector designed for a single ended 50 ohm antenna or an inverted-f antenna (selectable by moving 0ohm resistor). the rf section is designed for operation in the 2.4ghz frequency band.


圖2.cc85xxem參考設計電路圖