Integrated Device Technology has released what is said to be the world’s smallest 2W contactless-charging power receiver chip. In the future when all our internet-connected portable and wearable devices need a recharge after a busy day with their head in the cloud, contactless charging will be the way to go. The IDTP9026 wireless-charging receiver chip has a board footprint of just 30 square millimetres and is designed to charge a standard lithium-ion battery rated at 4.2 V. An AD pin allows the device to be switched out of the charging circuit when an external adapter is used for recharging. A separate enable pin is also available to turn the device off.
The chip uses an I2C interface bus so that an external processor can program the charging current, charging voltage, termination current and the thermal control loop for maximum flexibility and control. Readings back from the I2C bus include die and battery temperature, charging current and voltage, which can be used for custom control schemes or by the system's application and user interface. The IDTP9026 is compliant with the Wireless Power Consortium’s (WPC-1.1) standards.
To complete the charging system, IDT recommends the IDTP9038 matching single chip contactless power transmitter operating on 5 V.