STMicroelectronics LIS331DLTR

Overview

LIS331DLTR from STMicroelectronics is a 3-axis MEMS digital accelerometer with ±2g/±8g dynamically selectable full-scale range, I²C/SPI interface, embedded free-fall/motion detection, and click/double-click recognition. It operates from 2.16 V to 3.6 V, consumes <1 mW, and delivers 100 Hz or 400 Hz output data rates - used in motion-activated UIs, portable gaming controllers, and vibration-sensitive industrial monitoring systems.

For engineers reviewing the LIS331DLTR datasheet, LIS331DLTR pinout, LIS331DLTR application, or LIS331DLTR equivalent, key selection criteria include programmable interrupt thresholds (free-fall, wake-up), embedded high-pass filter configuration, self-test capability, and LGA-16 (3×3×1 mm) package compatibility with space-constrained PCB layouts.

Technical Context

The LIS331DLTR integrates a silicon MEMS sensing element with a CMOS interface IC trimmed for optimal matching. Its dual-mode digital interface supports both I²C (7-bit address with SA0 pin) and 4-wire/3-wire SPI, with configurable interrupt outputs (INT1/INT2) driven by user-programmable acceleration thresholds across all three axes.

Embedded functionality includes two independent interrupt generators (FF_WU_CFG_1/2), dedicated click/double-click logic with time-window and latency registers, and a factory-calibrated high-pass filter with configurable cut-off frequency - enabling real-time inertial event detection without host processor intervention.

Key Specifications

Pinout & Package

Package: LGA-16 (3 mm × 3 mm × 1 mm), land grid array with exposed pad for thermal dissipation and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-axis digital accelerometer applications.

Compared with LIS331DLTR, LIS3DHTR offers superior resolution and bandwidth but requires more PCB area and power; MMA8452Q simplifies firmware development for orientation-aware apps but lacks SPI support and programmable click timing parameters.

Availability

LIS331DLTR is available at Aetrix Electronics and suitable for portable gaming controllers, industrial vibration monitors, smartphone free-fall protection circuits, and wearable activity trackers requiring stable component supply across long production cycles.

Supply support for LIS331DLTR 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, specializing in MEMS sensors, microcontrollers, and power management ICs for industrial, automotive, and consumer markets.

The "nano" family - including LIS331DLTR - was designed for ultra-compact, low-power motion sensing in space-constrained portable electronics, emphasizing embedded intelligence and minimal host processing overhead.

FAQ

What communication interfaces does the LIS331DLTR support?

The LIS331DLTR supports both I²C (7-bit address with SA0 pin) and SPI (4-wire or 3-wire mode) through shared pins controlled by the CS pin. I²C mode activates when CS = 1; SPI mode engages when CS = 0. Both interfaces provide full register access, including interrupt configuration and self-test control, with documented timing margins per ST's datasheet Rev 3.

How is free-fall detection configured on the LIS331DLTR?

Free-fall detection is configured using FF_WU_CFG_1 (0x30) and FF_WU_THS_1 (0x32) registers. The threshold (in LSB) is set in FF_WU_THS_1, while FF_WU_CFG_1 enables axis selection, duration window, and interrupt routing to INT1 or INT2. Detection triggers when acceleration drops below threshold on ≥1 axis for ≥ programmed duration, with hardware-generated pulse output.

Does the LIS331DLTR require external components for basic operation?

Yes - two 100 nF ceramic decoupling capacitors (one each on Vdd and Vdd_IO) are mandatory per ST's layout guidelines. Pull-up resistors (~4.7 kΩ) are required on SCL/SDA for I²C mode. No external passive components are needed for SPI operation beyond standard trace routing rules for high-speed digital signals.

Can the LIS331DLTR operate from a 1.8 V supply?

No - the core analog supply (Vdd) requires 2.16 V minimum. However, Vdd_IO accepts 1.8 V, allowing direct interfacing with 1.8 V logic families while powering the sensor core from a separate 2.5 V or 3.3 V rail. This dual-supply architecture maintains accuracy and noise immunity without level shifters.