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LIS2DTW12

Product catalog summary

Overview: The LIS2DTW12 is an ultra-low-power, high-performance three-axis linear accelerometer and temperature sensor designed for applications such as motion and temperature monitoring, gesture recognition, and more. It is part of the 'femto' family, known for robust manufacturing processes.

Key Features:

Ultra-low power consumption: 50 nA in power-down mode, below 1 µA in active low-power mode.
Very low noise: down to 1.3 mg RMS in low-power mode.
Embedded temperature sensor with 0.8 °C typical accuracy.
Multiple operating modes and bandwidths.
Supply voltage range: 1.62 V to 3.6 V.
±2g/±4g/±8g/±16g full scale.
High-speed I²C/SPI digital output interface.
16-bit accelerometer and 12-bit temperature data output.
Self-test and 32-level FIFO buffer.
High shock survivability: 10000 g.

Applications:

Fragile shipment tracking.
Motion and temperature monitoring in battery-powered devices.
Gesture recognition and gaming.
Motion-activated functions and user interfaces.
Display orientation and tap/double-tap recognition.
Free-fall detection and smart power saving for handheld devices.

Specifications:

Measurement range: ±2g to ±16g.
Sensitivity varies with full scale and mode, e.g., 0.244 mg/digit at ±2g in high-performance mode.
Noise density: 90 µg/√Hz in high-performance mode.
Zero-g level offset accuracy: ±20 mg.
Temperature accuracy: ±0.8 °C (0 °C to 70 °C), ±1.3 °C (-40 °C to +85 °C).

Electrical Characteristics:

Supply voltage: 1.62 V to 3.6 V.
Current consumption varies with mode and ODR, e.g., 90 µA in high-performance mode.
Digital input/output voltage levels specified for high and low states.

Communication Interfaces:

SPI and I²C interfaces with specified timing values for standard and fast modes.
SPI clock frequency up to 10 MHz, I²C clock frequency up to 400 kHz in fast mode.

Operating Modes:

High-Performance Mode and four Low-Power Modes with different noise/power consumption trade-offs.
Low-noise setting can be enabled or disabled, affecting operating mode characteristics.

Absolute Maximum Ratings:

Supply voltage: -0.3 to 4.8 V.
Operating temperature range: -40 to +85 °C.
High shock survivability: 3000 g for 0.5 ms, 10000 g for 0.2 ms.

Operating Modes and Specifications: The sensor operates in various modes, including High-Performance and Low-Power Modes, each with different resolutions and operational data rates (ODR). The resolution is typically 14-bit, except for Low-Power Mode 1, which is 12-bit. The ODR ranges from 1.6 Hz to 1600 Hz, with bandwidth options depending on the mode and ODR. Noise density and current consumption vary across modes, with High-Performance Mode consuming more power.

Single Data Conversion On-Demand Mode: This mode allows for data conversion on-demand, triggered via I²C/SPI or a clock signal on the INT2 pin. It supports ODRs up to 200 Hz and transitions to power-down mode after data is saved.

Self-Test and Activity/Inactivity Functions: The self-test function checks sensor functionality by simulating input acceleration. The activity/inactivity function reduces power consumption by switching between low-power and full-performance modes based on detected motion.

Tap Detection and Offset Management: The device supports configurable tap detection parameters and allows offset management for output or wakeup detection using embedded hardware.

Sensing Element and IC Interface: The sensor uses a micromachined accelerometer with a capacitive measurement system. Data is accessed via I²C/SPI interfaces, with a data-ready signal for synchronization.

Factory Calibration and Temperature Sensor: The device is factory-calibrated for sensitivity and zero-g offset, with trimming parameters stored in nonvolatile memory. A temperature sensor provides data in a 12-bit format.

Application Hints: Proper electrical connections and power supply decoupling are essential for optimal performance. The device supports I²C and SPI communication, with programmable interrupt pins.

Digital Main Blocks and FIFO: The sensor includes digital filters and a FIFO buffer for efficient data handling. The FIFO can operate in various modes, including Bypass, FIFO, and Continuous, with a capacity of 32 samples per axis.

FIFO Management: The FIFO can store data samples, and when it reaches a threshold, a flag (FIFO_SAMPLES) is asserted. This flag can be routed to INT1 or INT2 pins. If an overrun occurs, the oldest data is overwritten. The FIFO can be emptied before it is full by reading the number of unread samples.

Operating Modes: Continuous-to-FIFO Mode: The FIFO operates continuously until a trigger event occurs, after which it switches to FIFO mode. The trigger can be various events like tap, wake-up, or free-fall. Bypass-to-Continuous Mode: Data storage starts in continuous mode upon a trigger event, and the sample following the trigger is stored in FIFO.

Digital Interfaces: The LIS2DTW12 supports both I²C and SPI interfaces. The I²C interface can operate in fast mode (400 kHz) and normal mode, with specific configurations for addressing and data transfer. The SPI interface can operate in 3-wire or 4-wire modes, with specific protocols for reading and writing data.

Register Mapping and Description: The document provides a detailed register map, including control registers, output registers, and status registers. Key registers include: OUT_T_L and OUT_T_H: These registers provide the temperature sensor output in 12-bit resolution. WHO_AM_I: A read-only register with a fixed value for device identification. CTRL1: Control register for setting output data rate and mode selection.

Key Tables and Figures: The document includes tables and figures illustrating the FIFO modes, digital interface pin descriptions, I²C and SPI protocols, and register maps. These visual aids help in understanding the configuration and operation of the LIS2DTW12 sensor.

Power Mode and Data Rate Configuration: The sensor's power mode and output data rate (ODR) are configured using the ODR[3:0] bits. Various settings allow for power-down mode and different frequencies ranging from 12.5 Hz to 1600 Hz, with options for high-performance and low-power modes.

Mode Selection: The MODE[1:0] bits determine the operational mode and resolution, offering low-power, high-performance, and single data conversion modes with resolutions of 12 or 14 bits.

Low-Power Mode Selection: The LP_MODE[1:0] bits select between four low-power modes, each with specific resolutions.

Control Registers: Several control registers (CTRL1 to CTRL6) manage various functionalities: CTRL2: Includes settings for boot, soft reset, and communication protocol configurations. CTRL3: Manages self-test, interrupt modes, and single data conversion settings. CTRL4 and CTRL5: Configure interrupt routing to INT1 and INT2 pads for various events like tap detection and data readiness. CTRL6: Handles bandwidth, full-scale selection, and noise configuration.

Status and Output Registers: The STATUS register provides flags for FIFO threshold, wakeup, sleep, tap events, and data readiness. Output registers (OUT_X_L, OUT_X_H, etc.) store the sensor's axis data in a 16-bit format.

FIFO Control: The FIFO_CTRL register allows configuration of FIFO modes and threshold levels, supporting modes like bypass, FIFO, and continuous.

Event Detection and Thresholds: Registers like TAP_THS_X, TAP_THS_Y, and TAP_THS_Z configure tap detection thresholds and enable axis-specific tap recognition. The INT_DUR register sets parameters for double-tap recognition, while WAKE_UP_THS and WAKE_UP_DUR manage wakeup thresholds and durations.

Free-Fall Detection: The FREE_FALL register configures the duration and threshold for free-fall event detection.

Register Descriptions and Specifications: FF_DUR and FF_THS Registers: The FF_DUR register is a 5-bit register that determines the duration of a free-fall event, with each LSB representing 1/ODR. The FF_THS register is a 3-bit register that sets the free-fall threshold at a full-scale range of ±2g. STATUS_DUP Register: This register provides event detection status, including FIFO overrun, temperature data readiness, sleep state, double-tap, single-tap, 6D orientation change, free-fall, and data readiness. WAKE_UP_SRC Register: This register indicates the status of free-fall, sleep, and wakeup events on the X, Y, and Z axes. TAP_SRC Register: This register provides the status of tap events, including single-tap, double-tap, and the sign of acceleration detected by the tap event on the X, Y, and Z axes. SIXD_SRC Register: This register indicates changes in position (portrait/landscape/face-up/face-down) and whether the X, Y, or Z axes exceed their respective thresholds. ALL_INT_SRC Register: This register resets all interrupt function flags related to sleep change, 6D orientation change, double-tap, single-tap, wakeup, and free-fall events. Offset Registers (X_OFS_USR, Y_OFS_USR, Z_OFS_USR): These registers store user-defined offset values for the X, Y, and Z axes, used for wakeup functions. CTRL7 Register: This register controls various settings, including data-ready interrupt mode, signal routing, interrupt enabling, user offset application, high-pass filter reference mode, and low-pass filter settings for 6D interrupt functions.

Package Information: The LIS2DTW12 is available in ECOPACK-compliant packages, meeting environmental standards. The LGA-12 package dimensions are 2.0 x 2.0 x 0.7 mm, with specific soldering and packing recommendations available.

Revision History: The document has undergone several revisions, with updates to figures and register descriptions.

Critical Information: The document highlights the importance of understanding the register configurations and operational modes for effective use of the LIS2DTW12 sensor. It also stresses the need for purchasers to stay updated with the latest product information and adhere to STMicroelectronics' terms and conditions.

Catalog excerpts

Product status link Features • Ultra-low power consumption: 50 nA in power-down mode, below 1 pA in active low-power mode • Very low noise: down to 1.3 mg RMS in low-power mode • 0.8 °C (typ. accuracy) embedded temperature sensor • Multiple operating modes with multiple bandwidths • Android stationary detection, motion detection • Supply voltage, 1.62 V to 3.6 V • High-speed I2C/SPI digital output interface • Single data conversion on demand • 16-bit accelerometer data output • 12-bit temperature data output • 10000 g high shock survivability • ECOPACK, RoHS and “Green” compliant • Fragile shipment tracking • Motion and temperature monitoring in battery-powered devices • Gesture recognition and gaming • Motion-activated functions and user interfaces • Display orientation • Tap/double-tap recognition • Free-fall detection • Smart power saving for handheld devices • Hearing aids • Portable healthcare devices • Wireless sensor nodes • Motion-enabled metering devices Description The LIS2DTW12 is an ultra-low-power high-performance three-axis linear accelerometer and temperature sensor belonging to the “femto” family which leverages on the robust and mature manufacturing processes already used for the production of micromachined accelerometers. The device has user-selectable full scales of ±2g/±4g/±8g/±16g and is capable of measuring accelerations with output data rates from 1.6 Hz to 1600 Hz. The LIS2DTW12 has an embedded 0.8 °C (typ. accuracy) temperature sensor with ODRs ranging from 50 to 1.6 Hz and resolution from 8 to 12 bits. DS12825 - Rev 3 - July 2019 For further information con

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The LIS2DTW12 has an integrated 32-level first-in, first-out (FIFO) buffer allowing the user to store data in order to limit intervention by the host processor. The embedded self-test capability allows the user to check the functioning of the sensor in the final application. The device has a dedicated internal engine to process motion and acceleration detection including free-fall, wakeup, highly configurable single/double-tap recognition, activity/inactivity, stationary/motion detection, portrait/landscape detection and 6D/4D orientation. The LIS2DTW12 is available in a small thin plastic land...

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LIS2DTW12 Block diagram and pin description Block diagram and pin description Block diagram Figure 1. Block diagram X+ Y+ CONTROL LOGIC TEMPERATURE SENSOR SELF TEST TRIMMING CIRCUITS CONTROL LOGIC & INTERRUPT GEN.

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1.2 Pin description Figure 2. Pin connections 10 111 | 12 |T]2 (TOPVIEW) DIRECTION OF THE DETECTABLE ACCELERATIONS (BOTTOM VIEW) 1. SDO/SA0 and CS pins are internally pulled up. Refer to Table 2. Internal pull-up values (typ.) for SDO/SA0 and CS pins for the internal pull-up values (typ).

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Table 2. Internal pull-up values (typ.) for SDO/SA0 and CS pins

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LIS2DTW12 Mechanical and electrical specifications @ Vdd = 1.8 V, T = 25 °C unless otherwise noted. The product is factory calibrated at 1.8 V. The operational power supply range is from 1.62 V to 3.6 V. Table 3. Mechanical characteristics 1. Typical specifications are not guaranteed. 2. Noise density is the same for all ODRs. Low-noise setting enabled. 3. RMS noise is the same for all ODRs. Low-noise setting enabled. 4. Values after factory calibration test and trimming.

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Table 4. Electrical characteristics 1. Typical specifications are not guaranteed. 2. It is possible to remove Vdd maintaining Vdd_IO without blocking the communication busses. In this condition the measurement chain is powered off. 3. Low-noise setting disabled. 4. Low-Power Mode 1. Low-noise setting disabled. 5. 4 mA is the maximum driving capability, ie. the maximum DC current that can be sourced/sunk by the digital pad in order to guarantee the correct digital output voltage levels Vqh and Vql.

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LIS2DTW12 Temperature sensor characteristics @ Vdd = 1.8 V, T = 25 °C unless otherwise noted. Table 5. Temperature sensor characteristics 1. Typical specifications are not guaranteed.

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LIS2DTW12 Communication interface characteristics 2.4.1 SPI - serial peripheral interface Subject to general operating conditions for Vdd and Top. Table 6. SPI slave timing values Note: Measurement points are done at 0.2Vdd_IO and 0.8Vdd_IO, for both input and output ports.

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LIS2DTW12 Communication interface characteristics Table 7. PC slave timing values 1. Data based on standard I2C protocol requirement, not tested in production. Figure 4. PC slave timing diagram Note: Measurement points are done at 0.2-VddJO and 0.8-VddJO, for both ports. page 10/65

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LIS2DTW12Communication interface characteristics Table 8. PC high-speed mode specifications at 1 MHz and 3.4 MHz

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LIS2DTW12 Absolute maximum ratings 2.5 Absolute maximum ratings Stresses above those listed as “absolute maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Table 9. Absolute maximum ratings This device is sensitive to mechanical shock, improper handling can cause permanent damage to the part. This device is sensitive to electrostatic discharge (ESD), improper handling can cause permanent damage...

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Sensitivity Sensitivity describes the gain of the sensor and can be determined by applying 1 g acceleration to it. As the sensor can measure DC accelerations this can be done easily by pointing the axis of interest towards the center of the Earth, noting the output value, rotating the sensor by 180 degrees (pointing to the sky) and noting the output value again. By doing so, ±1 g acceleration is applied to the sensor. Subtracting the larger output value from the smaller one, and dividing the result by 2, leads to the actual sensitivity of the sensor. This value changes very little over temperature...

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LIS2DTW12

LIS2DTW12

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