STMicroelectronics transmitter and receiver evaluation boards accelerate Qi wireless charger development

【Lansheng Technology News】On December 6, 2023, STMicroelectronics launched a wireless charging transmitter and receiver evaluation board based on STWLC38 and STWBC86 chips to simplify the development of 15W Qi wireless chargers.

The STEVAL-WLC38RX board is equipped with the STWLC38 5W/15W receiver chip, and the STEVAL-WBC86TX board is equipped with the STWBC86 5W transmitter chip, which helps developers quickly develop and test wireless charger prototypes. Both boards support the STSW-WPSTUDIO graphics software environment to assist in charger development.

STWLC38 receiver chip supports Qi 1.3 Extended Power Profile (EPP) 15W charging protocol and Baseline Power Profile (BPP) 5W charging protocol. Therefore, this receiver chip can also be used as a 5W transmitter in a wireless charger and has a reverse power transmission function to charge the device. This chip integrates a synchronous rectifier and a low dropout (LDO) linear regulator, which can convert the power of the receiving coil into an adjustable DC output voltage of 4V-12V, with a power transmission efficiency of 85%. STMicroelectronics' Adaptive Rectifier Configuration (ARC) mode maximizes the effective charging area, extends the typical detection range of the receiver by 50%, and increases the freedom of device spatial positioning for the most efficient power transfer.

This 5W transmitter chip STWBC86 that complies with the Qi 1.2.4 BPP protocol integrates a high-energy-efficiency, low-impedance full-bridge inverter and driver to ensure that the receiver chip has very low power dissipation and minimizes the bill of materials cost. By adjusting the applied PWM frequency and duty cycle, the chip is able to control the power delivered by the transmitter coil.

Both chips support wide-voltage inputs, simplifying integration with consumer and industrial products. Each chip uses an Arm® Cortex®-M0+ digital core to dynamically manage charging power for optimal energy efficiency. On-chip integrated non-volatile memory (NVM) can host advanced functions and upgrade charging protocols through firmware updates.

Both chips come in tiny chip-scale packages, making them suitable for very compact applications. The STWLC38 wireless charging receiver chip comes in a 2.12mm x 3.32mm WLCSP40 package, while the STWBC86 transmitter comes in a 3.26mm x 3.67mm WLCSP72 package. Both chips have built-in thermal management and electrical protection features.

Both evaluation boards accelerate the development of transmitter and receiver chip-based solutions for a variety of consumer, medical and industrial applications including smartphones, tablets, smartwatches, wearables, personal medical devices, Drug delivery devices, portable ultrasound equipment, toothbrushes, razors, computer peripherals, hearing aids, charging cases, power tools and mobile robots.