The STEVAL-WBC2TX50 evaluation board is based on the STWBC2-HP integrated circuit (IC) and is designed for wireless power transmitter applications, allowing users to quickly start a 5 W Qi BPP, 15 W Qi EPP or 50 W STSC wireless charging project.

The STWBC2-HP wireless transmitter IC provides power transfer levels for the following inductive wireless power technologies:

• Up to 5 W charging power, compatible with Qi 1.3 Baseline Power Profile (BPP)

• Up to 15 W charging power, compatible with Qi 1.3 Extended Power Profile (EPP)

• Provides up to 50 W charging power using STSC profile

BPP and EPP are specified by the Wireless Power Consortium's Qi specification.

This evaluation board is designed to operate from a 5-20 V input voltage or USB PD power adapter.

Two interfaces are open to the user: UART for monitoring and control via the STSW-WBC2STUDIO graphical user interface (GUI), and SWD JTAG for direct NVM access. Both interfaces are accessible through the STLINK-V3MINIE bridge.

STEVAL-WBC2TX50 includes multiple safety mechanisms providing over-temperature (OTP), over-current (OCP), over-power (OPP), over-voltage (OVP) and Vin drop protection as well as foreign object detection (FOD) for reliable designs.

▶Scenario application diagram

▶Display board photo

▶Solution block diagram

Core technology

• STWBC2-HP wireless power transmitter chip

• Synchronous boost DC-DC converter powers the bridge

• Onboard full-bridge inverter

• Rx presence detection based on coil Q-factor measurement

• Foreign object detection (FOD) function

• On-chip thermal management and protection

• SWD + UART combo connector

• Qi charger certification using STSAFE-A110 secure element

Project specifications

• Qi protocol: compatible with Qi 1.3

• Tx application PCB size: 68mm x 53mm

• Tx copper wire specifications: inductance value 10uH, DCR 50 mOhm, ACR 20 mOhm, @ 100 kHz, size 53.3mm × 53.3 mm × 4.5mm

• Qi Tx topology: MP-A2

• Input voltage: 5-20V

• Input current: <6 A

• Efficiency: Using STEVAL-WBC98RX, the efficiency is 85% (50W)

• Applicable charging gap Tx and Rx coil:

3 mm - 50 W STSC operation using STEVAL-WLC98RX. on the USB PD input.

3–15 mm (50 W output), with STEVAL-WLC98RX receiver. Provides a fixed 20V voltage to the barrel jack.

Maximum 20 mm. Provides a fixed voltage of 20 V to the barrel jack. Reduce maximum output power.

• Working mode: transmitter only.