STMicroelectronics Accelerates Development of Qi Wireless Chargers

STMicroelectronics is simplifying development of Qi-compliant wireless chargers up to 15W by introducing transmitter and receiver evaluation boards based on the company’s STWLC38 and STWBC86 ICs. Responding to the fast growing demand for products supporting the Qi wireless standards, these new development solutions will allow developers to quickly build and test wireless-charger prototypes. Both are used with the STSW-WPSTUDIO graphical software environment to assist development.
 
The new STWLC38 receiver IC from STMicroelectronics supports the Qi 1.3 15W Extended Power Profile (EPP) and 5W Baseline Power Profile (BPP). It can also perform as a 5W transmitter and allows reverse power transfer for device-to-device charging. Integrating a synchronous rectifier and low-dropout (LDO) linear regulator, the IC converts power from the receiver coil to a programmable 4V-12V DC output voltage, with power-transfer efficiency of 85%. ST’s Adaptive Rectifier Configuration (ARC) mode, which maximizes the usable charging area, extends the typical receiver-detection distance by 50% and increases spatial freedom to position devices for optimal power transfer.

The STWBC86 Qi 1.2.4 BPP-compatible 5W transmitter integrates a high-efficiency, low-impedance full-bridge inverter and drivers, which ensures low power dissipation and minimizes the bill of materials. The IC controls the energy transferred through the transmitter coil by adjusting the applied PWM frequency and duty cycle.
 
Both ICs operate with a wide input-voltage range, which eases use in consumer and industrial products. Each is dynamically managed with an Arm Cortex-M0+ digital core for optimum efficiency. Integrated non-volatile memory (NVM) permits hosting advanced features and allows protocol evolution by updating firmware.

Housed in tiny chip-scale packages, both are suited to use in very compact applications. The STWLC38 wireless power receiver comes in a 2.12mm x 3.32mm WLCSP40, while the STWBC86 transmitter is in 3.26mm x 3.67mm WLCSP72. Thermal management and electrical protection are built in.

The evaluation boards accelerate the development of solutions based on the transmitter and receiver ICs for a wide range of consumer, medical, and industrial applications. These include smartphones, tablets, smartwatches, and other wearables, personal medical devices, drug-delivery devices, portable ultrasound devices, toothbrushes, shavers, computer peripherals, hearing aids, charging cases, power tools, and mobile robots.
 
Both evaluation boards are available now from STMicroelectronics, priced at $72.28 for the STEVAL-WLC38RX receiver board and $84.53 for the STEVAL-WBC86TX transmitter.
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