ST unveils 70W high-power chipsets

STMicroelectronics’ new STWLC98 integrated wireless power receiver is able to deliver faster wireless charging and flexible charge sharing for a diverse range of portable and mobile devices.

The device, when combined with the STWBC2-HP transmitter IC - the complete transmitter-receiver system - can deliver up to 70W on the receiver end at high system efficiency.

The STWLC98 can fully charge high-end smartphones, which contain high-capacity batteries, in just under 30 minutes. In addition, the device extends opportunities for ultra-fast and convenient charging, free of cables, sockets, and restrictive connections, to a host of new applications and contexts. In addition, contactless charging will help developers to simplify enclosure designs, reducing cost and complexity and encourage new slimline styles.

Compliant with the Qi EPP 1.3 wireless-charging standard commonly used in the smartphone industry, the STWLC98 is managed by a 32-bit Arm Cortex-M3 core that supports a range of rich features including built-in protection; it comes with an embedded OS that simplifies Qi 1.3 standalone certification.

On the transmitter side, the STWBC2-HP can work with ST’s STSAFE-A110 secure element to store official Qi Certificates and provides authentication that leverages state-of-the-art cryptography. Support for the company’s ST Super Charge (STSC) protocol enables fast charging up to the maximum power-transfer rate of 70W.

The STWLC98 features the company's proprietary Adaptive Rectifier Configuration (ARC) mode that enhances the ping-up and power transfer spatial freedom of the system in both horizontal and vertical directions without any change in hardware or coil optimization. Enabling ARC mode, which transforms the whole surface of the transmitter as usable charging area, increases the ping-up distance by up to 50% in all directions.

The STWLC98 works directly with the STWBC2-HP, which contains a USB-PD interface, digital buck/boost DC/DC converter, full-bridge inverter, three half-bridge drivers, and voltage, current, and phase sensors. Controlled by a Cortex-M0+ core, the STWBC2-HP executes a patented fast PID loop and also supports the STSC protocol.

With built-in power management, the STWLC98 has an energy-saving ultra-low-power standby mode while total end-to-end charging system efficiency can exceed 90%, complying with stringent eco-design targets. The power charger chip features dedicated hardware and advanced algorithms that were developed to address challenges in ASK and FSK communication during high power delivery.

Safety features include foreign object detection (FOD), which leverages high-accuracy current-sense IP, Q-factor detection, and robust communication between transmitter and receiver

As an additional feature that gives users extra flexibility, the STWLC98 can also operate in high-efficiency transmitter mode to allow high-power charge sharing between devices. This is coupled with the STWLC98’s industry-first embedded Q-factor detection in a receiver device to ensure safe operation in transmitter mode.