2-Wire I/F supports simultaneous charging and communication
5V power, ^I2C communication, interrupt signal, 5 GPIOs
ams announced POW:COM technology, a 2-wire connection interface that simultaneously supports charging and communication between true wireless earbuds and the charging cradle. Existing true wireless earbuds required six pins for charging and communication functions between the cradle and the earbuds, which imposed mechanical design constraints on implementing a small form factor that fits snugly in the ear.

ams's POW:COM interface technology simultaneously supports data communication at a pure transmission speed of 1kbps and a charging current of over 150mA. Additionally, it uses an AS3442 host IC in the cradle and an AS3447 client IC in each earbud.

The POW:COM protocol provides 5V power transmission, ^I2C communication, interrupt signals, and up to 5 GPIOs through a single transmission line between AS3442 and AS3447 devices.

Utilizing the communication capabilities of the POW:COM interface can enhance the user experience of the charging cradle. For example, the earbuds can request battery information from the charging cradle and then display it through a mobile app.

By utilizing the POW:COM interface, earbud manufacturers can implement many other useful features, such as automatic recharging, automatic pairing between the user's smartphone and earbuds when the charging cradle case is opened, and accessory firmware updates during charging.

“Ams’s POW:COM interface significantly reduces mechanical constraints on true wireless earbud design,” said Cristian Feierl, Marketing Manager at ams. “By reducing the number of cradle connection pins from six to two, designers gain the flexibility to miniaturize earbuds or reduce surface area, and provide more value to users.”

The AS3442 and AS3447 POW:COM devices are currently in mass production. Some manufacturers are already producing earbuds equipped with ams POW:COM devices, and these products are expected to be released this December.