1.1. Features
 Operation voltage from 2.8 V to 4.2 V
 9 mA average current for A2DP
 300 uA for 500 ms sniff current
 0.8 uA deep sleep current
 Bluetooth 4.2 classic and low energy
 A2DP v1.3, AVRCP v1.6, HFP v1.7, HID v1.1, AVCTP v1.4, AVDTP v1.3, and SPP v1.2
 True wireless stereo and two active link
 Two wires UART download interface
 16 bits stereo ADC and DAC
 Stereo line in and dual microphone
 Five bands digital hardware equalizer
 SPI, UART, I2C, SDIO and USB
 I2S master and slave interface with MCLK output
 Interface for external PA and LNA
 Up to 220 mA battery charge controller