STMicroelectronics STEVAL-ISB043V1

Overview

STEVAL-ISB043V1 from STMicroelectronics is a Qi-compliant 2.5 W wireless power receiver evaluation board built around the STWLC33 IC, designed specifically for compact wearable devices. It integrates the STWLC33 transceiver, preloaded firmware, optimized coil interface (Wurth 760308101309), I²C host interface, and foreign object detection (FOD), operating as a regulated voltage source with NVM-configurable parameters.

For engineers reviewing the STEVAL-ISB043V1 datasheet, STEVAL-ISB043V1 pinout, STEVAL-ISB043V1 application, or STEVAL-ISB043V1 equivalent, this board enables rapid validation of Qi 1.2.2 receiver behavior in space-constrained wearables, including parameter tuning via I²C, FOD threshold calibration, and VRECT-to-VOUT regulation under dynamic coupling conditions.

Technical Context

The board implements the STWLC33's integrated synchronous rectifier, buck regulator, and digital control loop to deliver up to 2.5 W at 5 V output from a Qi-compliant transmitter. Its 10×6 mm active area and 3-layer PCB support integration into wristbands and ear-worn form factors.

It uses a dedicated RX coil (Wurth 760308101309) mounted on a 1.3 mm plastic fixture, with analog sensing paths for VRECT, ISH, ISL, and HVOD enabling real-time coil voltage/current monitoring and FOD decisioning per Qi specification v1.2.2.

Key Specifications

Availability

STEVAL-ISB043V1 is available at Aetrix Electronics and suitable for wearable electronics development, Qi receiver compliance testing, and low-power wireless charging integration requiring stable component supply and full firmware+hardware reference support.

Supply support for STEVAL-ISB043V1 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.

This evaluation board belongs to ST's Wireless Charging Evaluation Kit product line, engineered to accelerate Qi receiver implementation in size- and efficiency-critical wearable applications with minimal layout risk and validated firmware stack.

FAQ

Does STEVAL-ISB043V1 include the STWLC33 IC and production-ready firmware?

Yes. The board ships with the STWLC33 wireless power receiver IC pre-soldered and loaded with factory firmware supporting Qi v1.2.2 communication, FOD, and configurable regulation. Firmware can be updated via I²C using ST's official tools and documentation (UM2229).

Can the STEVAL-ISB043V1 be used with non-Wurth coils?

No - the board layout, component values (including CPAR = 2.2 nF), and firmware calibration are specifically tuned for the Wurth 760308101309 coil. Substituting other coils requires re-characterization of resonance, FOD thresholds, and buck loop compensation.

What is the role of the BST1/BST2 pins on the STWLC33 as implemented on this board?

BST1 and BST2 are bootstrap capacitor connections for the internal high-side gate drivers of the synchronous rectifier. On STEVAL-ISB043V1, they are routed to 15 nF/50 V X7R capacitors (CBOOT1/CBOOT2) placed adjacent to the IC to ensure stable gate drive during 125 kHz AC-to-DC conversion.

Is foreign object detection (FOD) enabled and calibrated out-of-box?

Yes. FOD is fully functional upon power-up using factory-calibrated thresholds stored in the STWLC33's NVM. The board reports FOD events via the INT pin and allows real-time adjustment of sensitivity and timing parameters over I²C per UM2229 guidelines.