STMicroelectronics STEVAL-MKI155V1

Overview

STEVAL-MKI155V1 from STMicroelectronics is a microphone coupon daughterboard designed for acoustic performance evaluation of four MP45DT02-M digital MEMS microphones, featuring PDM single-bit output, 61 dB SNR, -26 dBFS sensitivity, and 120 dBSPL acoustic overload point, used with the STEVAL-MKI126Vx Smart Voice kit in voice interface development.

For engineers reviewing the STEVAL-MKI155V1 datasheet, STEVAL-MKI155V1 pinout, STEVAL-MKI155V1 application, or STEVAL-MKI155V1 equivalent, this board enables rapid validation of multi-microphone array behavior, PDM timing alignment, supply voltage margining (1.64–3.6 V), and omnidirectional acoustic response in embedded voice capture systems.

Technical Context

The board implements a fixed-function analog-to-digital signal path using four identical MP45DT02-M MEMS microphones, each with integrated ASIC providing PDM output synchronized to an external clock. Power conditioning includes dual decoupling (100 nF + 10 µF) per microphone section.

Interfacing follows a standardized 3-pin header (CLK, DOUT, LR) per microphone, supporting time-division multiplexed PDM data streaming. The LR signal serves as word select for left/right channel framing, though all microphones are mono and omnidirectional.

Key Specifications

Availability

STEVAL-MKI155V1 is available at Aetrix Electronics and suitable for voice interface prototyping, far-field speech capture validation, and MEMS microphone parameter benchmarking requiring stable component supply and documented reference design integration.

Supply support for STEVAL-MKI155V1 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 STEVAL (ST Evaluation) product line, created to accelerate sensor subsystem evaluation and algorithm development for voice, audio, and environmental sensing applications.

FAQ

What is the primary function of the STEVAL-MKI155V1 board?

The STEVAL-MKI155V1 is a coupon-style daughterboard hosting four MP45DT02-M digital MEMS microphones. Its sole purpose is acoustic performance evaluation-enabling side-by-side comparison of sensitivity, SNR, and overload behavior under identical electrical and mechanical conditions when interfaced with the STEVAL-MKI126Vx host board.

Does the board support I²S or TDM output formats?

No. The STEVAL-MKI155V1 only supports PDM output as defined by the MP45DT02-M's native interface. Each microphone outputs a single-bit PDM stream synchronized to an externally supplied clock; no on-board format conversion to I²S or TDM is implemented or supported.

Can the microphones be used independently without the STEVAL-MKI126Vx host?

Yes-each microphone section has dedicated VDD, GND, CLK, DOUT, and LR connections via 3-pin headers (J1, J2). With appropriate external clock generation and PDM-capable digital input (e.g., MCU with PDM peripheral), individual microphones can be operated standalone, though no onboard voltage regulation or level-shifting is provided.

What mechanical mounting options does the board provide?

The board features four 2.54 mm pitch mounting holes (one near each microphone) and no integrated standoffs or enclosures. It is intended for temporary fixture-based acoustic testing-not permanent enclosure integration. No gasket, sealing, or directional acoustic baffling is included.