Accessory charging & communication for smart earbuds

Features
- Show battery level of charging box on phone
- Automatically pair TWS with phone when opening charging case
- Accessory firmware updates

Benefits
- Simultaneous battery charging & communication with only two pins
- Reduced number of mechanical connections to accessory
- Enables smaller footprint with enhanced communication capabilities
- Less influence on accessory design
- No Bluetooth component required in charging cradle

Product parameters
Interface: I2C
Package: WL-CSP16
Size [mm]: 2.25 x 2.25 x 0.6

General Description
Bluetooth earphones are gaining popularity and mobile charging for these devices is mandatory. Both, earphones and charger cradle, are equipped with electronics and sensors, but the connection between the charging case and the earphones is typically limited to two wires – ground and power. Without enhancing the capabilities of the two wires only power transfer for charging the battery is possible.

The AS3442/47 allows to extend the functionality of the two wire connection to enable charging and simultaneous communication to the earpiece. The MCU inside the charger cradle can request data from the earphone while the charging process is on-going and vice versa. In order to operate the system two chips per side are necessary. The master device (AS3442), which is typically located in the charger cradle, and a client device (AS3447), which is located in the accessory.

Parameter Name	Parameter Value
Interface Type	PCI
Other characteristics	2-channel