AS3447_EVALUATION_BOARD ams

Accessory charging and communication for smart earbuds with POW:COM www.ams.com/POWCOM POW:COM enables simultaneous battery charging and data exchange between charger cradle, earpiece and mobile phone - Two pins per device increase design flexibility and improve charging reliability - Improved user experience with enhanced communication capabilities General Description Bluetooth earphones are gaining popularity and mobile charging for these devices is device (AS3442), which is typically located in the charger cradle, and a client device 2 mandatory. Both, earphones and charger cradle, are equipped with electronics and (AS3447), which is located in the accessory. The master device features an I C interface sensors, but the connection between the charging case and the earphones is typically typically connected to a MCU inside the charger cradle to initiate the single wire con- 2 limited to two wires ground and power. Without enhancing the capabilities of the nection to the client device. Furthermore it enables readout of AS3447 register and I C 2 two wires only power transfer for charging the battery is possible. sensors which are connected to the AS3442 I C master interface. An interrupt signal line The AS3442/47 allows to extend the functionality of the two wire connection to enable is available to detect status changes on GPIOs or if communication is interrupted. 2 charging and simultaneous communication to the earpiece. The MCU inside the charger The client device features besides the I C master interface up to 5 GPIOs which can be cradle can request data from the earphone while the charging process is on-going and controlled via the host MCU. An interrupt input pin is available whose status signal is vice versa. In order to operate the system two chips per side are necessary. The master also transferred to host MCU accordingly. Bene ts Features - Simultaneous battery charging (up to 150mA) and - Showing the battery level of the charging box communication to earpiece with only two pins on the phone (instead of LED on the box itself) - Reduced number of mechanical connections - Automatically pair wireless earbuds with the phone to accessory when opening the charging case - Enables smaller footprint with enhanced - Restoring acoustic parameters to earphone communication capabilities in production line for ANC, beamforming after calibration - Increased design exibility of accessory - Enabling headphone makers to build smaller - Enables data exchange between charger and better-looking earbuds cradle and accessory - Accessory Firmware Updates Block Diagram Charger Cradle Earphone Power Charger Battery DCDC Step Up RES n IRQ Power Charger 2 Power 2 I C I C IRQ PWR IRQ GPIO PMU POWER GPIO 2 I C AS3442 2 I C 2 GROUND 2 I C I C Power Sensor 5 Management IRQ IRQ MCU Sensor 4 AS3447 PWR www.ams.com products ams.com 01/2018 by ams Subject to change without notice Headquarters SSales ales OO c ces es WWororldwide ldwide ams AG sales-sales-eureuropope amse ams.c.comom Tobelbader Strasse 30, 8141 Premstaetten, Austria sales-asia amssales-asia ams.c.comom Phone +43 3136 500-0 Fax +43 3136 525-01 sales-americsales-americsales-americas amsas amsas ams.c.c.comomom Li-Ion Battery MCU 2 I C Master 2 I C Slave 2 I C Master Bluetooth