ST STEVAL-WBC86TX User Manual

Introduction
The STEVAL-WBC86TX evaluation board, based on the STWBC86, is designed for wireless power transmitter applications and
allows its users to quickly start their 5 W Qi BPP wireless charging projects.
The STWBC86 wireless transmitter IC can deliver up to 15 W (coil dependent), however this reference design document is
limited to only provide sufficient information to develop a project for up to 5 W charging compatible with Qi 1.2.4 Baseline Power
Profile (BPP) power transfer by Wireless Power Consortium’s inductive wireless power technology.
The integrated circuit requires only a few external components and can work with 5-20 V input voltage.
Using an on-board USB-to-I2C bridge, the user can monitor and control the STWBC86 using the STSW-WPSTUDIO graphical
user interface (GUI).
The STEVAL-WBC86TX includes several safety mechanisms providing overtemperature (OTP), overcurrent (OCP), and
overvoltage (OVP) protections as well as foreign object detection (FOD) for reliable designs.
Figure 1. STEVAL-WBC86TX board
To get started with the STEVAL-WBC86TX, the following items are needed to use the reference design kit:
• Evaluation kit components:
– STEVAL-WBC86TX board
Getting started with the STEVAL-WBC86TX wireless power transmitter evaluation
board for up to 5 W Qi-BPP applications
UM3161
User manual
UM3161 - Rev 1 - July 2023
For further information contact your local STMicroelectronics sales office.
www.st.com

ST STEVAL-WBC86TX Specifications

General

Brand	ST
Model	STEVAL-WBC86TX
Category	Motherboard
Language	English

Summary

Introduction

Reference Design Specifications

Overview of the Board

Test Points

Identifies connectors and test points on the board for signal access.

Basic Operating Modes

Explains the transmitter's operation, pinging, and power transfer initiation.

Graphical User Interface (GUI)

Connecting STWBC86 to PC GUI

Details connecting the evaluation board to a PC using a USB Type-C cable and the GUI.

Patch and Configuration Files

Explains firmware updates using patch files and device configuration via configuration files.

Configuration File Generation

Describes how to generate configuration files using the STSW-WPSTUDIO GUI for version control.

Header File

Explains the generation of header files containing configuration and patch data for easier device programming.

Header File Generation

Details the process of generating a custom header file for device programming using the GUI.

Programming the Device

Outlines three methods for programming the device: direct GUI register changes, header files, or separate memh files.

Device Description and Operation

System Block Diagram

Presents a high-level block diagram of the STEVAL-WBC86TX evaluation board's architecture.

Power-Up Sequence

Explains the device's power-up sequence, including firmware loading and operating mode initialization.

Protections Overview

Provides an overview of hardware and software protections for safe operation.

Foreign Object Detection (FOD)

Details the Foreign Object Detection mechanism, its purpose, and tuning parameters.

WPC Qi Wireless Power Transfer

Describes the steps to achieve power transfer according to Qi 1.2.4 Baseline Power Profile.

Bidirectional Communication

Explains power transmission control and bidirectional communication using ASK and FSK.

I2C Interface

Details the I2C interface, including protocol, data validity, and register access methods.

Frequency Hopping (fhop)

Explains the fhop feature for improving communication by shifting operating frequency to avoid interference.

PID Tuning

Covers PID tuning for power regulation, discussing scaling factors and parameter adjustments.

STEVAL-WBC86TX Description and Operation

STWBC86 Default Configuration

Lists the default parameters for the STWBC86, including topology, protection, and features.

Typical Performance Characteristics

Details typical performance metrics of the evaluation board.

Power-Up Waveforms

Shows power-up waveforms of the STWBC86/STWLC38 setup under specific load conditions.

Efficiency and Spatial Freedom in the XY Plane

Evaluates efficiency and spatial freedom (XY plane) for STEVAL-WBC86TX with a specific receiver setup.

Efficiency and Spatial Freedom in the Z-axis

Analyzes efficiency and spatial freedom (Z-axis/charging gap) at various distances.

Thermal Performance

Presents thermal performance data of the board under a 5W load after continuous operation.

Designing a 5 W Wireless Power Transmitter based on the STEVAL-WBC86TX Evaluation Board

External Component Design

Guides on selecting external components critical for board performance, impacting device functions.

Coil Selection

Discusses coil selection factors like inductance, DCR, current rating, and dimensions for optimal performance.

Series Resonant Capacitor Selection

Explains selecting series capacitors based on coil design to achieve resonance near 100 kHz.

Hardware Input Protections

Recommends hardware protections like TVS diodes and fuses for overvoltage and overcurrent.

Ring Node Voltage Sensing

Details ring node voltage measurement for FOD using the DFT pin and a recommended resistor divider.

PCB Layout Guidelines

Provides guidelines for PCB layout, emphasizing wide tracks for high current and ground plane usage.

Reference Code with STM32 Development Boards

Guides on using reference code with STM32 development boards.

Hardware Connections

Explains connecting the STWBC86's I2C pins to a master I2C bus, including pull-up resistors.

Reference Code Porting Procedure

Guides on porting the reference code to an STM32 project using STM32CubeIDE.

Error Codes

Lists and describes error codes encountered during I2C operations and NVM programming.

Schematic Diagrams

Bill of Materials

STEVAL-WBC86TX PCB Layout

Board Versions

Regulatory Compliance Information

Appendix A Thermal Measurements

Revision History