Interface Enables True Wireless Earbuds


The invention of ams, POW:COM is an innovative interface technology that enables power and communication between a true wireless earbud and a charging cradle over a two-wire connection. 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.


The ams POW:COM interface technology enables simultaneous data communication with a 1-kb/s net data rate and a greater-than 150-mA charging current. It 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.


Communications capability supports an enhanced user experience of the charging cradle. For instance, the earbud can request the battery information from the charger cradle and display it on a mobile app. The interface also allows the earbud manufacturer to implement other 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.


The AS3442 and AS3447 POW:COM devices are available now in production volumes. An evaluation board is also available. For more details, visit the product page as well as the AS3442 datasheet and AS3447 datasheet.