TI 公司的CC85xx系列产品是低功耗高性价比的2.4GHz RF系统级芯片(SoC),适合用于高质量数字音频的无线传输.器件包括内置的无线音频发送协议,并能控制所选的外部音频设备.具有自适应的跳频和正向误差修正(FEC),空中数据速率5Mbps,可编程输出功率高达+3dBm,接收灵敏度-83dBm ,主要用在无线高质量数字音频,点对点音频链接,无线USB耳机,无线USB扬声器和无线2.1扬声器系统.本文介绍了CC85xx系列主要特性, CC8520/CC8530应用电路, CC8521/CC8531应用电路以及CC85xxDK开发板和PurePath无线AudioEB电路图.
2.4 GHz RF SoC FOR WIRELESS DIGITAL AUDIO STREAMING
The PurePath™ Wireless platform is a cost-effective and low-power solution optimized for wireless transmission of high-quality digital audio. The CC85xx includes a robust built-in wireless audio transmission protocol and can control selected external audio devices. Utilizing numerous coexistence mechanisms allows the CC85xx to avoid interfering with, or being interfered by other 2.4 GHz radio systems. The CC85xx 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 CC85xx interfaces easily with other TI audio ICs and DSPs (using I2S and DSP/TDM interfaces). More details can be found in the CC85xx Family User Guide.

CC85xx系列主要特性:
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
No software development needed when used in autonomous mode
External system
Can be used autonomously, or can be controlled by an external host MCU for greatest flexibility
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 × 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, –87dBm 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)

CC85xx系列应用:
- Wireless high-quality digital audio
- Wireless point-to-point audio link
- Wireless (USB) headphones / headsets
- Wireless (USB) loudspeakers
- Wireless 2.1 speaker systems
- CC852x supports up to 2 channels
- CC853x supports up to 4 channels
- CC85x1 supports USB

图1.CC8520/CC8530应用电路

图2.CC8521/CC8531应用电路

CC85xxDK开发板
The CC85xxDK is a complete development kit for the CC85xx from Texas Instruments. The hardware included in the kit must be used together with the PurePath Wireless (PurePath Wireless) Configurator[9], which can be downloaded from the TI website. The development kit can be used through all stages of development of applications with CC85xx:
 Evaluate CC85xx RF performance and range testing
 Test wireless sound quality

 Interface to a variety of interfaces including codec and digital/optical inputs and outputs Support some TI Codec interface board platforms
 Support for programming interface with the PurePath Wireless Configurator PC software.
   Figure 3 shows the main components of the CC85xxDK.
 2 pcs Purepath Wireless AudioEB
 2 pcs CC8531EM Evaluation Module, RF reference design to be plugged into PurePath Wireless AudioEB
 2 pcs CC8531+CC2590EM, RF reference design with extended range to be plugged into PurePath Wireless AudioEB
 1 pcs CC debugger, used for program CC85xx in a PurePath Wireless AudioEB or in an end customer application

图3. CC85xxDK开发板外形图

The CC85xxDK is designed to test and evaluate high quality wireless audio with CC85xx with a variety standard input and output audio format. The development kit also has a programming interface to ease testing and development of complete audio applications.
The AudioEB can easily be set up to demonstrate:
 Wireless headsets
 Wireless speaker systems
 Wireless Audio Cable Replacement
 Simple Human Interaction functionality (Volume control, link indication and pairing)
The following audio interfaces are supported directly on the board:
 Optical and coaxial S/PDIF inputs
 Optical and coaxial S/PDIF outputs
 Line in
 Line out
 Microphone/stereo audio input
 Headphone output
In addition to the audio interface supported directly the following interfaces are supported using plug-in boards
 Texas Instruments ADC/DAC/CODEC EVM modules
 Texas Instruments Class D amplifier EVM modules (TAS57XX series)

图4. PurePath无线AudioEB电路图(1)

图5. PurePath无线AudioEB电路图(2)

图6. PurePath无线AudioEB电路图(3)

图7. PurePath无线AudioEB电路图(4)

图8. PurePath无线AudioEB电路图(5)

图9. PurePath无线AudioEB电路图(6)