STMicroelectronics STEVAL-MKI126V1

Overview

STEVAL-MKI126V1 from STMicroelectronics is a demonstration board for digital microphone signal processing, built around the STA321MPL scalable digital microphone processor and two on-board MP45DT02 PDM MEMS microphones. It converts up to six PDM microphone inputs into three independent I²S streams and filtered PWM outputs, enabling real-time voice enhancement, biquad filtering, and headset audio playback in voice-enabled embedded systems.

For engineers reviewing the STEVAL-MKI126V1 datasheet, STEVAL-MKI126V1 pinout, STEVAL-MKI126V1 application, or STEVAL-MKI126V1 equivalent, this board supports rapid evaluation of multi-microphone array interfaces, I²S/PWM output interoperability with audio receivers and digital amplifiers, and APWorkbench-based configuration of 32-bit programmable biquad filters per channel.

Technical Context

The board implements a fully digital audio preprocessing path: PDM inputs from up to six MEMS microphones are synchronized, decimated, and routed through up to 10 user-programmable 32-bit biquad filters per channel before being formatted into I²S (3 independent lanes) or PWM outputs. The STA321MPL handles clock management, sample rate conversion, and level shifting without analog signal paths.

It features dual voltage regulation (3.3 V and 1.8 V), dedicated microphone array connectors, APWorkbench software control via USB-to-serial bridge, and compatibility with eight other ST evaluation boards including STEVAL-MKI129V1/V2/V3 and STEVAL-MKI131V1/V2/V3 - enabling modular expansion of microphone count and processing topology.

Key Specifications

Availability

STEVAL-MKI126V1 is available at Aetrix Electronics and suitable for voice interface development, smart speaker prototyping, and far-field microphone array validation requiring stable component supply and full evaluation board traceability.

Supply support for STEVAL-MKI126V1 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 management ICs, and analog/mixed-signal solutions for industrial, automotive, and consumer applications.

The STEVAL-MKI126V1 belongs to ST's STSmartVoice evaluation platform family, engineered specifically to accelerate development of high-fidelity, multi-microphone voice capture systems for voice assistants, conferencing devices, and IoT edge audio nodes.

FAQ

What microphone types and configurations does the STEVAL-MKI126V1 support?

The board natively supports PDM-output MEMS microphones, including the on-board MP45DT02 units. It accepts up to six PDM inputs via soldered sockets or an external six-microphone array connector. All inputs are synchronized and decimated by the STA321MPL, with no support for analog or I²S microphones.

Can the STEVAL-MKI126V1 operate standalone without a host PC?

No - the board requires connection to a host PC running ST's APWorkbench software to configure filter coefficients, select I²S/PWM output modes, and manage microphone routing. It lacks onboard non-volatile storage or boot firmware for autonomous operation.

Does the board provide analog audio output capability?

Yes - the filtered PWM output is low-pass filtered onboard to generate a line-level analog signal compatible with standard 3.5 mm headset jacks. This enables real-time listening to processed microphone audio without external DACs or amplifiers.

Which ST evaluation boards is the STEVAL-MKI126V1 compatible with?

The board is explicitly designed for interoperability with STEVAL-MKI129V1/V2/V3, STEVAL-MKI131V1/V2/V3, STEVAL-MKI116V1, STEVAL-MKI117V1/V2, and STEVAL-CCA035V1 - allowing daisy-chaining, shared clock distribution, and unified APWorkbench control across multi-board microphone arrays.