STMicroelectronics STEVAL-MKI021V1

Overview

STEVAL-MKI021V1 from STMicroelectronics is a MEMS 3-axis ±2g analog-output demonstration board built around the LIS331AL nano accelerometer. It integrates a linear voltage regulator and rail-to-rail low-noise quad amplifier configured as non-inverting buffers, providing both direct and buffered sensor outputs. Designed for rapid evaluation of motion sensing in portable consumer electronics, it supports self-test activation and power-down control via accessible pins.

For engineers reviewing the STEVAL-MKI021V1 datasheet, STEVAL-MKI021V1 pinout, STEVAL-MKI021V1 application, or STEVAL-MKI021V1 equivalent, this board delivers verified analog output conditioning, shock survivability up to 10000g/0.1s, and RoHS-compliant hardware for immediate bench-level validation of LIS331AL-based motion interfaces.

Technical Context

The board implements the LIS331AL - a capacitive 3-axis linear accelerometer with analog voltage outputs (VOUT_X, VOUT_Y, VOUT_Z) referenced to VDD (2.16–3.6 V). Its signal chain includes dedicated non-inverting buffer stages per axis, enabling high-impedance interfacing with ADCs or instrumentation circuits without loading the raw MEMS output.

Power management is supported through dedicated PWR_DOWN and SELF_TEST control terminals, each pulled high via onboard resistors and accessible via 0.1" headers. The integrated LDO ensures stable 3.3 V supply to the LIS331AL and op-amps, decoupled with ceramic capacitors per ST's layout recommendations.

Key Specifications

Availability

STEVAL-MKI021V1 is available at Aetrix Electronics and suitable for motion sensor evaluation, analog interface prototyping, and MEMS characterization requiring stable component supply in R&D labs, academic settings, and embedded design validation workflows.

Supply support for STEVAL-MKI021V1 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 devices for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) platform family, engineered to accelerate hands-on validation of ST MEMS sensors by delivering fully assembled, tested, and documented hardware with reference schematics and layout guidance.

FAQ

What is the primary function of the STEVAL-MKI021V1?

The STEVAL-MKI021V1 is a ready-to-use demonstration board for evaluating the LIS331AL 3-axis analog-output accelerometer. It provides direct access to unbuffered and buffered analog outputs (X/Y/Z), power-down and self-test controls, and a regulated 3.3 V supply - enabling immediate signal integrity testing and system integration assessment without custom PCB design.

Does the board require external power regulation?

No. The board includes an integrated linear voltage regulator that accepts 4.5–5.5 V DC input and generates a stable 3.3 V supply for the LIS331AL and op-amps. Input is applied via a standard 2-pin screw terminal or solder pads, with on-board decoupling capacitors ensuring noise immunity per ST's recommended layout.

How are the analog outputs configured?

The board provides two parallel output paths per axis: raw sensor outputs (labeled OUT_X/Y/Z) and buffered outputs (labeled BUF_OUT_X/Y/Z), each routed to 0.1" pitch headers. The buffers are unity-gain non-inverting amplifiers using ST's TS912 quad op-amp, offering high input impedance (>10¹² Ω) and low output impedance (<1 Ω) for driving ADC inputs or oscilloscope probes.

Is the STEVAL-MKI021V1 still in active production?

No. STMicroelectronics has marked STEVAL-MKI021V1 as obsolete (as noted in Doc ID 18300 Rev 1). However, Aetrix Electronics maintains legacy inventory for continued engineering support, including full documentation access, schematic review, and compatibility guidance for migration to active alternatives like STEVAL-MKI109V2 or LSM6DSOX-based platforms.