STMicroelectronics STEVAL-MKI139V2

Overview

STEVAL-MKI139V2 from STMicroelectronics is a microphone coupon evaluation board featuring four detachable PCB coupons, each populated with one MP33AB01H analog MEMS microphone. It operates from 1.5 V to 3.6 V, delivers 66 dB SNR, supports 100 Hz–10 kHz frequency response, and provides -38 dBFV sensitivity with 125 dBSPL acoustic overload point.

For engineers reviewing the STEVAL-MKI139V2 datasheet, STEVAL-MKI139V2 pinout, STEVAL-MKI139V2 application, or STEVAL-MKI139V2 equivalent, this board enables rapid acoustic performance validation of ST's bottom-port analog MEMS microphones in real-world PCB integration scenarios including spatial audio capture, beamforming prototyping, and SNR/THD benchmarking.

Technical Context

The board implements four independent MP33AB01H microphone circuits, each with dedicated biasing and output buffering for analog signal integrity. Each coupon includes test points for VDD, GND, and analog output, supporting single-microphone isolation without soldering.

All microphones share a common supply rail and are designed for bottom-port acoustic coupling-requiring mounting on a PCB with an acoustic cavity beneath the device. The layout maintains consistent trace impedance and minimizes crosstalk between adjacent channels.

Key Specifications

Availability

STEVAL-MKI139V2 is available at Aetrix Electronics and suitable for voice interface development, acoustic sensor qualification, and multi-microphone array prototyping requiring stable component supply and repeatable test conditions.

Supply support for STEVAL-MKI139V2 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 components for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series-engineered specifically to accelerate customer evaluation of ST's MEMS audio sensors through modular, solder-free, and layout-validated hardware.

FAQ

What is the purpose of the detachable coupon design?

Each coupon is a standalone 12 mm × 12 mm PCB section containing one MP33AB01H microphone, test points, and bias circuitry. Users can physically separate coupons to integrate individual microphones into custom carrier boards-preserving ST's reference layout and acoustic performance without redesigning front-end analog routing.

Does STEVAL-MKI139V2 include signal conditioning or ADC functionality?

No. The board provides only analog output from each MP33AB01H microphone. It does not include amplification, filtering, or analog-to-digital conversion. Signal processing must be implemented externally using an MCU or audio codec with analog input capability.

Can this board be used for beamforming algorithm development?

Yes. The fixed 20 mm inter-microphone spacing across the 4-coupon layout supports basic time-difference-of-arrival (TDOA) analysis. Engineers use it to collect synchronized analog waveforms for offline beamforming validation-though external multi-channel ADC synchronization is required.

Is the MP33AB01H on this board bottom-port or top-port?

The MP33AB01H devices mounted on STEVAL-MKI139V2 are bottom-port analog MEMS microphones. The board's mechanical cutouts and PCB stack-up are optimized for acoustic coupling through the bottom side-requiring placement on a host board with an open cavity aligned beneath each microphone.