1 W wearable wireless power system based on STWBC-WA and STWLC04

The STEVAL-ISB038V1 is a wireless battery charger reference design evaluation kit designed for ultra-compact battery operated devices, such as wearable gear, smartwatches, Internet of Things sensors and healthcare devices.

The design is optimized for 1-watt wireless power transfer with a half-bridge topology on the transmitter side and with tiny 11 mm and 20 mm coils on the receiver and transmitter sides, respectively. For power transfers up to 3 watts, the design can be modified by using larger coils and a full-bridge configuration on the transmitter.

The STWBC-WA transmitter can support a cost-effective half-bridge topology (full-bridge optional) and a powerful software API lets you modify the behavior of LED and general purpose IOs as well as connecting external peripherals or devices like sensors to the design via the on-chip I²C and UART ports.

The STWLC04 is designed for 1-watt power transfer based on the Qi protocol, with digital control and precise analog control loops ensuring stable operation. The I²C interface allows a high degree of customization and settings can be stored in the embedded non-volatile memory.

Key Features

  • Wearable KIT characteristics:
    • 11 mm coil on Receiver
    • 20 mm coil on Transmitter
    • 1 Watt delivered on Receiver side
    • USB 5 V input
    • Foreign Object Detection (FOD) optional
    • Graphical interface for monitoring behavior
    • Total reference design
    • RoHS compliant
  • STWBC-WA Wireless power transmitter:
    • Cost effective Half Bridge topology with integrated drivers
    • Optional Full Bridge configuration for 3 W applications
    • Active presence detector
    • 2-layer PCB to facilitate design
    • Turnkey solution or customizable via APIs
    • Parametric customization via Graphical interface
  • STWLC04 wireless power receiver:
    • Output voltage: 5 V regulated voltage
    • Integrated high efficiency synchronous rectifier
    • Li-Ion/Li-Pol charger functionality
    • 4-layer PCB to facilitate design




Technical Documentation

Product Specifications
Description Version Size
DB2997 DB2997: 1 W wearable wireless power system based on STWBC-WA and STWLC04 3.0 711 KB
Application Notes
Description Version Size
AN4900 AN4900: How to tune STEVAL-ISB038V1 wireless charging evaluation kit for wearable applications 4.0 1 MB
User Manuals
Description Version Size
UM2098 UM2098: Getting started with the STEVAL-ISB038V1R wearable wireless power receiver based on STWLC04 5.0 1 MB
UM2099 UM2099: Wireless charger transmitter evaluation board based on STWBC-WA for wearable applications 3.0 19 MB

Hardware Resources

Board Manufacturing Specifications
Description Version Size
STEVAL-ISB038V1 gerber files 1.1 707 KB
Bill of Materials
Description Version Size
STEVAL-ISB038V1 BOM 1.1 173 KB
Schematic Pack
Description Version Size
STEVAL-ISB038V1 schematics 1.1 929 KB

Publications and Collaterals

Description Version Size
Wireless power kit for IoT devices 07.2017 729 KB


License Agreement
Description Version Size
Evaluation products license agreement 1.4 128 KB

Tools and Software

Embedded Software
Evaluation Tool Software
Evaluation Tools
Solution Evaluation Tools
Support & Community

Sample & Buy

Part Number Core Product Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
STEVAL-ISB038V1 ActiveCARDIndustrialEcopack2

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.