STMicroelectronics Transmitter and Receiver evaluation boards accelerate Qi wireless charger development

     STMicroelectronics introduces wireless charging transmitter and receiver evaluation boards 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.

     The STWLC38 receiver chip supports the 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 transfer function for device to device charging. The chip integrates a synchronous rectifier and a low voltage difference (LDO) linear regulator to convert power from the receiving coil to a 4V-12V adjustable DC output voltage with an 85% power transfer efficiency. St's Adaptive Rectifier Configuration (ARC) mode maximizes the effective charging area, extends the receiver's typical detection distance by 50%, and increases the freedom of device spatial positioning for the most efficient power transfer.

     The Qi 1.2.4 BPP compliant 5W transmitter chip STWBC86 integrates a high energy efficiency, low impedance full bridge inverter and driver to ensure low dissipated power on the receiver chip, minimizing bill of material costs. By adjusting the applied PWM frequency and duty cycle, the chip can control the power transmitted 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 with firmware updates.

     Both chips are packaged in a microchip-scale package, 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.

     These two evaluation boards can accelerate the development of transmitter and receiver chip-based solutions for a variety of consumer, medical and industrial applications. These include smartphones, tablets, smartwatches, wearables, personal medical devices, drug delivery devices, portable ultrasound devices, toothbrushes, razors, computer peripherals, hearing AIDS, charging cases, power tools and mobile robots.