Panthronics samples PTX30W single chip for NFC wireless battery charging

Fabless semiconductor company Panthronics is sampling the PTX30W, an NFC wireless charging listener circuit, packaged in a space-saving 1.78mm x 1.78mm chip. It is supplied in a compact 3.2mm2 WL-CSP.

It is, said Panthronics, the industry’s only integrated, single chip for the listener circuit in NFC wireless charging systems. 

The PTX30W combines a rectifier, NFC tag, battery charger, power management and 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 when not. A sophisticated battery charger circuit in the PTX30W 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, easing thermal management in sealed, space-constrained enclosures, explained Panthronics. 

The PTX30W enables manufacturers of small battery-powered products to implement NFC wireless charging with a board which is around four times smaller than existing designs based on multiple discrete components, said the company. 

As a single chip, the PTX30W is easier to implement than a circuit made of multiple discrete components. The autonomous PTX30W runs an NFC Forum-derived wireless charging protocol which supports power negotiation. It can therefore operate in stand-alone mode with no need for an external microcontroller to run NFC wireless charging operations. 

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

Both the PTX30W and PTX130W are supported by a software development kit to accelerate integration into end product designs. 

The PTX30W is also available now for sampling. Volume production orders will start shipping in Q2 2023.

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