June 2008

Rev1

1/17

AN2768

Application note

LIS331DL 3-axis digital MEMS accelerometer:

translates finger taps into actions

Introduction

This document is intended to provide application information for the LIS331DL low-voltage

3-axis digital output linear MEMS accelerometer housed in an LGA package.

The LIS331DL is an ultra-compact low-power 3-axis linear accelerometer that includes a

sensing element and an IC interface capable taking information from the sensing element

and providing the measured acceleration data to external applications via an I2C/SPI serial

interface.

The sensing element used to detect acceleration is manufactured using a dedicated process

developed by ST to produce inertial sensors and actuators in silicon.

The IC interface is instead manufactured using a CMOS process that allows a high level of

integration to design a dedicated circuit which is factory trimmed to better match the sensing

element characteristics.

The LIS331DL has a user-selectable full scale of ±2 g and ±8 g and is capable of measuring

accelerations with an output data rate of 100 Hz or 400 Hz. A self-test capability allows the

user to check that the system is operating correctly.

The device features two independent, highly programmable interrupt sources that can be

configured either to generate an inertial wake-up interrupt signal when a programmable

acceleration threshold is exceeded along one of the three axes, to detect a free-fall or to

recognize single/double click events.

Two independent pins can be configured to provide interrupt signals to connected devices.

The LIS331DL is available in a plastic SMD package and is designed to operate over a

temperature range extending from -40 °C to +85 °C.

The ultra small size and weight of the SMD package make it an ideal choice for handheld

portable applications such as cell phones and PDAs, or any other application where

reduced package size and weight are required.

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