Fabless semiconductor company, Panthronics is sampling the PTX30W, claimed to be the only single-chip solution for the listener circuit in NFC wireless charging systems.

It combines a rectifier, NFC tag, battery charger and power management as well as protocol handling. The NFC tag supports bi-directional data communication in NFC Type A mode. This enables the transfer of data between the charging cradle and the charged device, such as the battery’s state of charge or fault indicators, as well as enabling firmware upgrades of both devices.

The device’s power management unit supplies the chip from RF power when available, or from the battery. A battery charger circuit regulates the input voltage from the antenna to match the voltage profile of the constant current/constant voltage charge supplied to the li-ion battery. This minimises power losses in the charger to improve thermal management in sealed, space-constrained enclosures.

The device is supplied in a compact 3.2mm² WL-CSP which enables manufacturers of small battery-powered products to implement NFC wireless charging with a board which is around four times smaller than existing designs which are based on multiple discrete components. It is also easier to implement than a circuit made of multiple discrete components, says the company.

The autonomous PTX30W runs an NFC Forum-derived wireless charging protocol which supports power negotiation. As a result, the device can operate in standalone mode without an external microcontroller to run NFC wireless charging operations.

Paired with an NFC poller, such as the PTX130W in the charging cradle, the PTX30W can supply up to 1W to charge the li-ion battery in fitness trackers, smart watches, earbuds, hearing aids, smart glasses, smart rings, styluses and medical sensors.

The company also provides a software development kit to accelerate integration into end product designs.

The PTX30W is available now for sampling, with volume production orders due to start shipping in Q2 2023.