separated, and the lower side of BT shall have no other interference, we recommend Bluetooth module on the bottom corner. There BT, with op amp, amplifier, MCU, etc. Layout supply line is recommended when using the star alignment and ensure that the performance of the Bluetooth module power supply line is better.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.* Better to use a standalone charge module 39 SPK_LP audio left channel positive differential output terminal.38 SPK_LN Audio left channel differential output negative end.37 SPK_RP audio right channel positive differential output terminal.36 SPK_RN audio right channel negative differential output terminal.35 LINE_BP Mike 2 positive terminal (not used).34 LINE_BN Mike 2 negative terminal (not used).32 LINE / MIC_AP Mike 1 positive terminal.26 MUTE (PIO0) Mute control (mute, after a period of time is low).25 PP / CALL (PIO7) Play / Pause / receive calls / back / re-pair.24 USB_P USB differential signal positive.23 USB_N USB differential signal negative.19 CHARGE External Battery Charge Management (5V).18 MFB / POWER module enable control, active-high (delay of 30ms must power).43 RFOUT antenna (default built-in antenna, external disconnect).42 SPK_L_P1 audio left channel positive differential output terminal.41 SPK_L_N1 Audio left channel differential output negative end.40 SPK_R_P1 audio right channel positive differential output terminal.39 SPK_R_N1 audio right channel negative differential output terminal.38 MIC_BP Mike 2 positive terminal (not enabled).
19 BAT_SENSE External Battery Charge Management.18 CHG_EXT External Battery Charge Management.15 POWER_EN module enable control, active-high (delay of 30ms must power).9 SPI_EN burned into the program interface enable pin (high enable).8 MOSI burned into the program interface.7 CLK burned into the program interface.5 MISO burned into the program interface.Adapter plate size 31x25mm for 8645 and 29x24mm for 8635.Audio performance supports ACC, MP3, SBC, APT-X decoder.External Interface USB (USB sound card).Transmission power support Class1 / Class2 / Class3 maximum adjustable 9dbm for 8645, and 8dbm for 8635.Bluetooth protocol HFPV1.6, A2DPV1.2, AVRCPV1.4, HSPV1.2.Supply voltage DC3.3-4.2V, ≤3.0V automatic shutdown, ≤3.2V alarm.