A true wireless earbud previously required as many as six pins to provide both power transfer and communication between the charging cradle and the earbud, compromising the mechanical design of a small form factor that fits comfortably in the user’s ear.
The ams says its POW:COM enables simultaneous data communication with 1kBit/s net data rate and over 150mA charging current is supported.
The POW:COM interface is implemented with the AS3442 host IC in the cradle, and the AS3447 client IC in each earbud. The POW:COM protocol developed by ams provides for power transfer at 5V, I2C communication, interrupt signals and up to five GPIOs via a single transmission line between each pair of AS3442 and AS3447 devices.
The POW:COM interface is designed to allow the earbud manufacturer to implement features such as auto-recharge, automatic pairing of the earbuds with the user’s phone on opening the charging cradle’s case, and accessory firmware updating while charging.
An evaluation board for the POW:COM interface parts is available on ams online shop. For sample requests or for more technical information, click here.