STMicroelectronics 70W High-Power Wireless Charging Chipset Improves Charging Speed, Energy Efficiency and Flexibility

     STMicroelectronics' STWLC98 highly integrated wireless charging receiver chip brings faster wireless charging and flexible power sharing to a wide range of portable and mobile devices for home, office, industrial, healthcare and in-vehicle applications. When used in conjunction with the STWBC2-HP transmitter chip, the complete wireless charging transceiver system can provide up to 70W of power output at the receiver side while ensuring high system energy efficiency.

      The STWLC98 can fully charge today's high-end smartphones with large-capacity batteries in under 30 minutes. In addition, the new products expand ultra-fast and convenient charging opportunities into many new application areas and environments, without the tethers of cables, sockets and connections. In addition, contactless charging also allows designers to simplify product enclosure design, reducing design cost and complexity, while facilitating new slimline design styles and eliminating socket-related issues, such as jack dust.

     The STWLC98 is compliant with the Qi EPP 1.3 wireless charging standard commonly used in the smartphone industry, and the main controller is a 32-bit Arm® Cortex®-M3 microcontroller that supports a rich set of features, including internal protection. The chip has an embedded operating system that simplifies Qi 1.3 independent certification. On the transmitter side, the STWBC2-HP can be used in conjunction with ST's STSAFE-A110 security module to store Qi official certificates and utilize advanced encryption techniques for device authentication. The new products also support STMicroelectronics' innovative STSC supercharging protocol, which enables power transfer speeds of up to 70W.

     The STWLC98 uses ST's proprietary Adaptive Rectifier Configuration (ARC) mode, which enhances the system's ping-up distance and power transfer spatial freedom in both horizontal and vertical directions without changing hardware or optimizing coils. When ARC mode is enabled, the entire surface of the transmitter becomes a usable charging area, increasing ping-up distance by 50% in all directions.

     STWLC98 can be used directly with STWBC2-HP, STWBC2-HP integrates a USB-PD interface, digital buck/boost DC/DC converter, full bridge inverter, three half bridge drivers, and voltage sensor, current sensor and phase sensor. The controller of the STWBC2-HP is a Cortex-M0+ core that implements a patented algorithm for fast PID looping and also supports the STSC protocol.

     ST's new 70W wireless charging chipset creates a scalable solution that can be deployed in smartphones, tablets, laptops, power banks, True Wireless Stereo (TWS) devices, Bluetooth® speakers and AR/VR Headphones and other equipment. Designers can also extend fast and convenient wireless charging to medical devices such as medical monitors and infusion pumps, as well as cordless power tools, mobile robots, drones, and e-bikes. The chipset is also suitable for automotive applications, including in-vehicle charging solutions for mobile devices and wireless charging of various in-vehicle modules.

     STWLC98 has built-in power management technology, and has an ultra-low power standby energy-saving mode. The total energy efficiency of the end-to-end charging system is higher than 90%, which meets strict ecological design goals. The new charger chip features dedicated hardware and advanced algorithms designed to address ASK and FSK communication challenges during high power transfers. Safety features include Foreign Object Detection (FOD), which utilizes high-accuracy current detection IP, Q-factor detection, and robust communication between transmitter and receiver to detect foreign objects touching the charging area.

     To provide users with additional flexibility, the STWLC98 has newly added the ability to switch to a high-efficiency transmitter mode for high-power power sharing between the two devices. The STWLC98 incorporates an industry-first embedded Q-factor detection technology in the receiver device to ensure safe charging in transmitter mode.

     Users of ST's wireless charging solutions can download and use ST Wireless Power Studio, a PC-based graphical interface tool software for faster design-in and simplified development, including calibration of FOD, adjustment of Q-factor detection and communication diagnostics. Both products are in mass production, the STWLC98 is available in a 4.3mm x 3.9mm, 90-ball, 0.4mm pitch WLCSP package; the STWBC2-HP is available in an 8mm x 8mm, 68-pin, 0.4mm pitch VFQFPN package