SN-508-8645蓝牙模块为本公司自主开发的智能型无线音频数据传输产品，是低成本的高效率的立体声无线传输方案，模块采用了CSR BC8芯片为模块提供了高品质的音质和兼容性，整体性能更优化。模块采用免驱动方式，客户只需要把模块接入应用产品，就可以快捷地实现音乐的无线传输，享受无线音乐的乐趣。
二：应用领域：
该模块主要用于短距离的音乐传输，可以方便地和笔记本电脑手机，PDA等数码产品的蓝牙设备相连，实现音乐的无线传输。
◆蓝牙音响
◆蓝牙立体耳机
◆免提电话
◆蓝牙无线传输音频
◆蓝牙拨号器
三：基本特性：
1.Bluetooth Profiles
◆Bluetooth v4.0 specification support
◆HFP v1.6
◆HSP v1.2
◆A2DP v1.2
◆AVRCP v1.4
◆Support for smartphone applications (apps)
2.Music Enhancements
◆Configurable 5-band EQ for music playback
(rock,pop, classical, jazz, dance etc)
◆SBC, MP3, AAC and Faststream decoder
◆Stereo widening (S3D)
◆Volume Boost
◆Support for voice recognition
◆Support for multi-language programmable audio prompts
◆CSR's proximity pairing and CSR's proximity connection
◆Multipoint support for HFP connection to 2 handsets for
3.voice
◆Multipoint support for A2DP connection to 2 A2DP sources for music playback
◆Talk-time extension
4. Improved Audio Quality
CSR’s latest 2-mic CVC audio enhancements for narrowband and wideband connections including::
◆1-mic far-end audio enhancements
◆Near-end audio enhancements )noise suppressionand AEQ)
◆Wind noise reduction
◆Packet loss concealment
◆Bit error concealment
◆Automatic gain control and automatic volumecontrol
◆Frequency expansion for improved speech intelligibility
◆mSBC codec support for wideband speech
四：性能参数：
型号 SN-508-8645
蓝牙规格 Bluetooth V4.0
调制方式 ∏/4 DQPSK,8DPSK
供电电压 3.3-4.2V
支持蓝牙协议 HFPV,1.6,HSPV 1.2,A2DPV1.2,AVRCPV1.4
工作电流 <20mA
待机电流 <50uA
温度范围 -40℃—80℃
无线传输范围 ≥10M
灵敏度 -80dB<0.1%BER频
频率范围 2.4GHZ—2.480GHz
对外接口 PIO,SPI,I2C and PCM,USB
音频性能 立体声支持ACC,MP3，SBC
音频信燥比 ≥75dB
失真度 ≤0.1%
模块尺寸 18.5mm*16.5mm
五：模块封装尺寸及引脚定义：
六：模块PIN功能说明：
PIN Symb I/O Description
1,12,38 GND Ground Ground connet battery negative
2 CSB_ SPI4 Bi-directional with weak pull-down Programmable Input/output Alternative function SPI chip selec PCM1 synchronous data sync
3,4 MISO_SPI3 MOSI _SPI2 Bi-directional with strong pull-down Programmable Input/output Alternative function: SPI data output PCMI synchronous data output
5 CLK _SPI5 Bi-directional with strong pull-down Programmable Input/output Alternative function SPI Clock
6,7 LED0 ,LED1 Open drain output LED Driver
8 MFB Regulator enable input Can also be sensed as an input. Regulator enable and multifunction button. A high input (tolerant to VBAT) enables the on-chip regulators, which can then be latched on internally and the button used as a multifunction input
9,10 PIO_16 PIO_13 Bi-directional with strong pull-down programmable Input/output
13 VBUS Charge input
14 CHG_EXT External battery charger control
15 EXT_SENSE Groung connet battery sense input
16 1V8 power 1.8v swith-mode power regulator Inductor connection
17 VBAT Battery positive internal
18 USB_N Bi-directional USB data
19 USB_P Bi-directional USB data
20 PIO_7 Bidirectional with strong pull-down Programmable input / output line 7.
21 PIO_9 Bidirectional with strong pull-down Programmable input / output line 9.
22 PIO_0 Bidirectional with strong pull-down Programmable input / output line 0.
23 USB3V3 3.3V bypass linear regulator output Positive supply for USB port.
Connect external minimum 2.2μF ceramic decoupling capacitor
24 PIO_1 Bidirectional with strong pull-up Programmable input / output line 1. Alternative function UART_TX: UART data output
25 PIO_8 Bidirectional with strong pull-up Programmable input / output line 8. Alternative function UART_TX: UART data output
26 PIO_21 Bidirectional with strong pull-up Programmable input / output line 21. Alternative function UART_TX: UART data output
27 PIO_20 Bidirectional with strong pull-up Programmable input / output line 20. Alternative function UART_TX: UART data output
28 MIC_BIAS Analogue in Micophone bias
29 MIC_1P Analogue in Line or mircophone input positive channel A
30 MIC_1N Analogue in Line or microphone input negative channelA
31 PIO_18 Bi-directional with weak pull-down Programmable input / output line18.
32,33 MIC_2N MIC_2P Analogue in Line input negative channel B
34 SPK_R_N Analogue out Speaker output negative right
35 SPK_R_P Analogue out Speaker output positive right
36 SPK_L_N Analogue out Speaker output negetive left
37 SPK_L_P Analogue out Speaker output positive left
39 RF_OUT VDD_ANA_RADIO Bluetooth 50Ω transmitter output /receiver input
40 PIO_19 Bi-directional with weak pull-down Programmable input / output line 19.
七：设计注意事项：
SN-508-8645属于双声道模组，SPKR_LN, SPKR_LP，SPKR_RN, SPKR_RP都有音频输出，属于立体声。
八：电路连接注意：
SN-508-8645外接功放的时候，必须接差分输入的功放，如果不接差分输入的功放，必须接一个运放平衡两个差分的电平，否则会有：“啪啪”的冲击声。
九：其他注意事项：
A．如果模组天线旁边有电池，金属物，液晶屏，喇叭等，要求离天线距离至少15MM
B．layout时供电线路建议使用星形走线，并确保蓝牙模组供电线性度要好，还有BT的地必须与运放，功放，MCU等的地分开，而且BT下侧不可有其它干扰地。
C．天线周围不可走控制线，电源线，音频线，MIC等干扰线。
D. 如果模组天线附近有排座，外壳有金属铁网等对信号有影响的，建议避开，可选用专业的高增益天线
