EXBT

Features

• Bluetooth v4.0
• A2DP v1.2；
• AVRCP v1.4；
• HFP v1.6；
• GAVDP1.2；
• HSP1.2；
• Dual MIC Input

Performance

• Model CSR8645
• Bluetooth specification Bluetooth V4.0
• Modulation GFSK, π / 4 DQPSK, 8DPSK
• Supply voltage DC3.3-4.2V, ≤3.0V automatic shutdown, ≤3.2V alarm
• Bluetooth protocol HFPV1.6, A2DPV1.2, AVRCPV1.4, HSPV1.2
• Working current ≤30mA
• Standby current <50uA
• Temperature range -40ºC ~ + 85ºC
• Wireless transmission range ≤10 meters
• Transmission power support Class1 / Class2 / Class3 maximum adjustable 9dbm
• Sensitivity -80dBm <0.1% BER
• Frequency Range 2.4GHz ~ 2.480GHz
• External Interface USB (USB sound card)
• Audio performance supports ACC, MP3, SBC, APT-X decoder
• Audio SNR ≥75dB
• Distortion ≤0.1%
• Module size 26.2x13.5x0.8mm
• Adapter plate size 31x25mm

Dimension

• 

  8645 Board

• 

  8645 Convert Board

Pin Definition

Name Number IO IO IO Description

1. 1 LED2 status indicator (not enabled)
2. 2 LED1 status lights
3. 3 LED0 status indicator
4. 4 AIO0 not enabled
5. 5 MISO burned into the program interface
6. 6 CSB program burned into port
7. 7 CLK burned into the program interface
8. 8 MOSI burned into the program interface
9. 9 SPI_EN burned into the program interface enable pin (high enable)
10. 10 TX serial TX (not enabled)
11. 11 RX serial RX (not enabled)
12. 12 VBUS 5V input charging port
13. 13 RST # low reset
14. 14 BAT power input (3.3 ~ 4.2V)
15. 15 POWER_EN module enable control, active-high (delay of 30ms must power)
16. 16 1.8V 1.8V output
17. 17 GND Power ground
18. 18 CHG_EXT External Battery Charge Management
19. 19 BAT_SENSE External Battery Charge Management
20. 20 PIO10 not enabled
21. 21 PIO11 not enabled
22. 22 PIO12 not enabled
23. 23 PIO13 not enabled
24. 24 USB_N USB differential signal negative
25. 25 USB_P USB differential signal positive
26. 26 MUTE (PIO9) Mute control (mute, after a period of time is low)
27. 27 PIO6 not enabled
28. 28 PP / CALL (PIO7) Play / Pause / receive calls / back / re-pair
29. 29 PIO8 not enabled
30. 30 PREV (PIO18) on a
31. 31 NEXT (PIO19) under a
32. 32 VOL- (PIO20) Volume down
33. 33 VOL + (PIO21) Volume up
34. 34 MIC_BIAS Mike bias voltage
35. 35 MIC_AN Mike 1 negative end
36. 36 MIC_AP Mike 1 positive terminal
37. 37 MIC_BN Mike 2 negative terminal (not enabled)
38. 38 MIC_BP Mike 2 positive terminal (not enabled)
39. 39 SPK_R_N1 audio right channel negative differential output terminal
40. 40 SPK_R_P1 audio right channel positive differential output terminal
41. 41 SPK_L_N1 Audio left channel differential output negative end
42. 42 SPK_L_P1 audio left channel positive differential output terminal
43. 43 RFOUT antenna (default built-in antenna, external disconnect)

Design Circuits

Bluetooth power up on boot

• VCC (3.3 ~ 4.2V), when using an external power supply: 3.3V (ASM1117) power supply. When using lithium batteries: lithium guarantee voltage between 3.3V ~ 4.2V;
• Recommendations Bluetooth module supply terminal in parallel with the capacitor 104 470uf suppress interference;
• 1V8 output voltage.
• As shown above connection, this time it did not work after the power module, because the module "PWER_E" is not enabled, as shown below on the electric start mode.

• 

  convert board simple power up

• 

  stable power up in application

Design note

• If the next antenna modules have batteries, metal, LCD screen, speaker, and requires a minimum distance from the antenna 3cm, it is recommended to use an external antenna.
• Layout supply line is recommended when using the star alignment and ensure that the performance of the Bluetooth module power supply line is better. There BT, with op amp, amplifier, MCU, etc. separated, and the lower side of BT shall have no other interference, we recommend Bluetooth module on the bottom corner.
• It recommended that the module antenna portion of the float in the floor, but can not go around the antenna control cable, power cable, audio cable, MIC and other interference lines, if the module to be placed in the middle, to be slotted in around the antenna, it is recommended to use an external antenna .
• If there is row seat near the antenna module, housing a metal iron net impact on the signal, it is recommended to use an external antenna to solve the distance problem.
• When an external amplifier module to be connected to the differential input of the amplifier, if you do not take a differential input amplifier, you must be connected to a balance of the two differential amplifier level, otherwise there will be "pops" the impact of sound.