STMicroelectronics STEVAL-ISB038V1

Overview

STEVAL-ISB038V1 from STMicroelectronics is a wireless battery charger reference design evaluation kit for ultra-compact wearable devices, built around the STWBC-WA transmitter IC and STWLC04 receiver IC. It delivers 1 W wirelessly using 20 mm transmitter and 11 mm receiver coils, supports Qi-compliant digital control, and features half-bridge topology with optional full-bridge upgrade to 3 W. Target applications include smartwatches, IoT sensors, and healthcare wearables.

For engineers reviewing the STEVAL-ISB038V1 datasheet, STEVAL-ISB038V1 pinout, STEVAL-ISB038V1 application, or STEVAL-ISB038V1 equivalent, this page provides verified hardware specifications, board-level I/O mapping, firmware configuration pathways via UART and SWIM, FOD and presence detection implementation details, and guidance on modifying coil size and bridge topology for power scaling.

Technical Context

The STEVAL-ISB038V1 implements a complete Qi v1.2.2–compliant wireless power transmitter reference design, centered on the STWBC-WA MCU-based controller with integrated drivers and analog sensing front-end. It uses a 2-layer PCB layout optimized for compact wearable integration, with dedicated analog inputs (ISENSE, WAVE_SNS, NTC_TEMP) and configurable GPIOs (LEDR, LEDG, PWM_AUX).

Power delivery operates at 110–205 kHz switching frequency, with 50% full-load efficiency measured using TDK WT151512-22F2 coil. Firmware customization is enabled via ST's STWBC GUI over USB-to-UART, supporting real-time parameter tuning, LED behavior reassignment, and external peripheral interfacing through I²C and UART ports.

Key Specifications

Availability

STEVAL-ISB038V1 is available at Aetrix Electronics and suitable for wearable device development, Qi-compliant wireless charging validation, and ultra-low-power IoT sensor prototyping requiring stable component supply and documented reference design support.

Supply support for STEVAL-ISB038V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, power management devices, and wireless solutions for industrial, automotive, and consumer markets.

The STEVAL-ISB038V1 belongs to ST's Wireless Charging Reference Design portfolio, engineered specifically to accelerate development of compact, Qi-certifiable wearable chargers with minimal bill-of-materials and software-configurable operation.

FAQ

What firmware tools are required to configure the STEVAL-ISB038V1?

The STWBC GUI software is mandatory for runtime configuration and firmware download via USB-to-UART. For low-level recovery or chip erasure, STVP with ST-LINK/V2 and SWIM interface is required. Both tools are freely available from STMicroelectronics' official website and support Windows XP or later with .NET Framework 4.

Can the STEVAL-ISB038V1 be used without the STWLC04 receiver?

Yes - the STEVAL-ISB038V1 transmitter board operates independently and can be paired with any Qi-compliant receiver. However, full system validation-including Foreign Object Detection and power handshake-requires a compatible receiver such as the STWLC04, which is included in the full STEVAL-ISB038V1 reference kit.

How is Foreign Object Detection (FOD) implemented on this board?

FOD is implemented via analog waveform analysis using the WAVE_SNS input (Pin 12) and current sensing on ISENSE (Pin 19). The STWBC-WA executes proprietary algorithms that monitor Q-factor shifts and power dissipation anomalies during symbol transmission, triggering shutdown if non-Qi objects are detected near the 20 mm transmitter coil.

What modifications are needed to scale output power from 1 W to 3 W?

To achieve 3 W, replace the default half-bridge configuration with full-bridge by enabling DRIVEOUT[2] and DRIVEOUT[3] (Pins 5 and 25), use a larger transmitter coil (e.g., ≥25 mm diameter), and update firmware parameters via STWBC GUI to adjust switching frequency, duty cycle, and thermal thresholds accordingly.