STMicroelectronics STEVAL-MKI250KA

Overview

STEVAL-MKI250KA from STMicroelectronics is a biosensor evaluation kit built around the ST1VAFE3BX vertical analog front-end (vAFE) IC, integrating biopotential signal acquisition and an ultralow-power AI-enabled accelerometer with antialiasing. It delivers ECG monitoring capability via 3.5 mm electrode interface, supports I²C/SPI communication, operates from 1.71–3.6 V supply, and features dual interrupt outputs (INT1/INT2) for real-time event detection.

For engineers reviewing the STEVAL-MKI250KA datasheet, STEVAL-MKI250KA pinout, STEVAL-MKI250KA application, or STEVAL-MKI250KA equivalent, this kit enables rapid validation of biopotential signal chain performance, low-noise ECG waveform capture, sensor fusion with on-board AI acceleration, and interoperability with STM32H5-based SensorTile platforms including STEVAL-MKI109V3, STEVAL-MKI109D, and STEVAL-MKBOXPRO.

Technical Context

The kit implements a complete biopotential signal path using the ST1VAFE3BX's dedicated vAFE architecture, which includes programmable gain (1–128×), configurable input routing (IN_+/IN_−), internal reference (VCM), and integrated antialiasing filtering. Its companion TSU111ICT rail-to-rail op-amp provides precision signal conditioning for QVAR electrode inputs.

Power management is handled by LD39015M12R LDOs delivering stable 1.2 V to analog sections, while decoupling (100 nF + 2.2 µF) ensures noise immunity across VDD and VDDIO rails. The embedded STM32H563ZI microcontroller acts as a USB-to-sensor bridge, enabling MEMS Studio GUI integration and custom firmware deployment.

Key Specifications

Availability

STEVAL-MKI250KA is available at Aetrix Electronics and suitable for remote patient monitoring, wearable ECG development, and clinical-grade biopotential research requiring stable component supply, traceable sourcing, and long-term BOM continuity.

Supply support for STEVAL-MKI250KA 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, sensors, power ICs, and analog devices for industrial, automotive, and consumer applications.

The STEVAL-MKI250KA belongs to ST's SensorTile ecosystem - a modular evaluation platform targeting intelligent IoT edge nodes where ultra-low-power biopotential sensing, AI-driven motion analysis, and seamless PC/cloud connectivity are essential design requirements.

FAQ

Does STEVAL-MKI250KA include firmware or only hardware?

STEVAL-MKI250KA includes pre-flashed firmware on its onboard STM32H563ZI microcontroller, enabling immediate plug-and-play operation with MEMS Studio. Source code and HAL drivers are provided in ST's official GitHub repository for customization, including raw sensor register access and real-time waveform export over USB CDC.

Can STEVAL-MKI250KA acquire ECG signals without external electrodes?

No - the kit requires external electrodes connected via the 3-pin QVAR headers or the 3.5 mm phone jack on STEVAL-MKE007A. The board itself contains no integrated electrodes; it provides the complete analog front-end, biasing, filtering, and digitization path but relies on physical contact through compliant biopotential electrodes for signal acquisition.

What is the role of the TSU111ICT op-amps on STEVAL-MKE006A/MKE007A?

The TSU111ICT rail-to-rail op-amps serve as precision instrumentation amplifiers for electrode signal conditioning: they provide high-input-impedance buffering, common-mode rejection, and adjustable gain before feeding signals into the ST1VAFE3BX's IN_+/IN_− inputs. Their low offset (±150 µV) and drift (<0.3 µV/°C) preserve ECG waveform fidelity.

Is STEVAL-MKI250KA RoHS compliant and certified for medical use?

Yes, STEVAL-MKI250KA is RoHS compliant per EU Directive 2011/65/EU. However, it is not a certified medical device - it is an evaluation tool intended for R&D and prototyping. Final medical product certification (e.g., FDA 510(k), CE-IVDR) must be pursued separately by the end equipment manufacturer based on full system validation.