一：產品概述：
SN-508-8645藍牙模塊為本公司自主開發的智能型無線音頻數據傳輸產品，是低成本的高效率的立體聲無線傳輸方案，模塊采用了CSR BC8芯片為模塊提供了高品質的音質和兼容性，整體性能更優化。模塊采用免驅動方式，客戶只需要把模塊接入應用產品，就可以快捷地實現音樂的無線傳輸，享受無線音樂的樂趣。
二：應用領域：
該模塊主要用于短距離的音樂傳輸，可以方便地和筆記本電腦手機，PDA等數碼產品的藍牙設備相連，實現音樂的無線傳輸。
◆藍牙音響
◆藍牙立體耳機
◆免提電話
◆藍牙無線傳輸音頻
◆藍牙撥號器
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：性能參數：
型號 SN-508-8645
藍牙規格 Bluetooth V4.0
調制方式 ∏/4 DQPSK,8DPSK
供電電壓 3.3-4.2V
支持藍牙協議 HFPV,1.6,HSPV 1.2,A2DPV1.2,AVRCPV1.4
工作電流 <20mA
待機電流 <50uA
溫度范圍 -40℃—80℃
無線傳輸范圍 ≥10M
靈敏度 -80dB<0.1%BER頻
頻率范圍 2.4GHZ—2.480GHz
對外接口 PIO,SPI,I2C and PCM,USB
音頻性能 立體聲支持ACC,MP3，SBC
音頻信燥比 ≥75dB
失真度 ≤0.1%
模塊尺寸 18.5mm*16.5mm
五：模塊封裝尺寸及引腳定義：
六：模塊PIN功能說明：
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：設計注意事項：
SN-508-8645屬于雙聲道模組，SPKR_LN, SPKR_LP，SPKR_RN, SPKR_RP都有音頻輸出，屬于立體聲。
八：電路連接注意：
SN-508-8645外接功放的時候，必須接差分輸入的功放，如果不接差分輸入的功放，必須接一個運放平衡兩個差分的電平，否則會有：“啪啪”的沖擊聲。
九：其他注意事項：
A．如果模組天線旁邊有電池，金屬物，液晶屏，喇叭等，要求離天線距離至少15MM
B．layout時供電線路建議使用星形走線，并確保藍牙模組供電線性度要好，還有BT的地必須與運放，功放，MCU等的地分開，而且BT下側不可有其它干擾地。
C．天線周圍不可走控制線，電源線，音頻線，MIC等干擾線。
D. 如果模組天線附近有排座，外殼有金屬鐵網等對信號有影響的，建議避開，可選用專業的高增益天線
