STMicroelectronics STEVAL-MKI129V1

Overview

STEVAL-MKI129V1 from STMicroelectronics is a microphone coupon daughterboard designed for integration with the STEVAL-MKI126Vx Smart Voice evaluation kit, hosting four MP45DT02 digital MEMS microphones with PDM output, 120 dBSPL acoustic overload point, 61 dB SNR, and -26 dBFS sensitivity for far-field voice capture in compact audio front-ends.

For engineers reviewing the STEVAL-MKI129V1 datasheet, STEVAL-MKI129V1 pinout, STEVAL-MKI129V1 application, or STEVAL-MKI129V1 equivalent, this board enables rapid validation of multi-microphone array performance, PDM interface timing alignment, acoustic beamforming feasibility, and MEMS microphone channel matching under real-world supply (1.64–3.6 V) and environmental conditions.

Technical Context

The board implements a fixed-layout 4-channel PDM microphone array using identical MP45DT02 devices, each operating from a shared 1.64–3.6 V supply and delivering synchronized single-bit bitstreams. No on-board clock generation or digital signal processing is included - timing and data capture rely entirely on the host STEVAL-MKI126Vx baseboard's PDM receiver logic.

Each microphone is mounted on an individual detachable PCB segment, enabling mechanical isolation testing and individual acoustic characterization. The coupon architecture supports direct soldering to carrier boards or plug-in use via the STEVAL-MKI126Vx connector interface, preserving native MEMS transducer behavior without analog amplification or filtering.

Key Specifications

Availability

STEVAL-MKI129V1 is available at Aetrix Electronics and suitable for voice-controlled IoT gateways, smart speaker reference designs, far-field ASR validation, and multi-microphone beamforming prototyping requiring stable component supply and documented ST evaluation hardware compatibility.

Supply support for STEVAL-MKI129V1 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, designing and manufacturing microcontrollers, sensors, power ICs, and analog/mixed-signal products for industrial, automotive, and consumer applications.

This board belongs to ST's Smart Voice evaluation platform family, developed specifically to accelerate development of high-fidelity, multi-microphone voice interfaces for always-on, low-power edge audio processing systems.

FAQ

Does STEVAL-MKI129V1 include a PDM decimation filter or audio codec?

No. The board contains only passive routing and four MP45DT02 microphones. PDM bitstream decimation, clock generation, and PCM conversion must be handled externally - typically by the STEVAL-MKI126Vx baseboard's STM32 MCU or dedicated audio processor. No onboard clock oscillator, ADC, or DSP resources are present.

Can STEVAL-MKI129V1 be used independently without STEVAL-MKI126Vx?

No. It is a daughterboard requiring the STEVAL-MKI126Vx baseboard for power regulation, PDM clock distribution, and digital interface routing. The board lacks voltage regulators, master clock sources, or host interface connectors - it mates exclusively via the defined 20-pin header interface.

What mechanical configuration do the four microphones use on this board?

The four MP45DT02 microphones are mounted on separate, breakaway PCB segments arranged in a linear 1×4 layout with 30 mm center-to-center spacing. This geometry supports basic delay-and-sum beamforming and allows individual detachment for isolated acoustic measurement per channel.

Is RoHS compliance verified for STEVAL-MKI129V1?

Yes. The board is explicitly declared RoHS compliant per the STMicroelectronics data brief (Doc ID 024077 Rev 1), confirming lead-free PCB finish, halogen-free laminates, and compliant passives and connectors meeting EU Directive 2011/65/EU requirements.