Micropower, 3-Axis, 200 g Digital Output, MEMS Data Sheet ADXL372 FEATURES GENERAL DESCRIPTION 200 g measurement range The ADXL372 is an ultralow power, 3-axis, 200 g MEMS 200 Hz to 3200 Hz user selectable bandwidth with 4-pole accelerometer that consumes 22 A at a 3200 Hz output data antialiasing filter rate (ODR). The ADXL372 does not power cycle its front end to Selectable oversampling ratio achieve its low power operation and therefore does not run the Adjustable high-pass filter risk of aliasing the output of the sensor. Ultralow power In addition to its ultralow power consumption, the ADXL372 Power can be derived from a coin cell battery has many features to enable impact detection while providing 22 A at 3200 Hz ODR, 2.5 V supply system level power reduction. The device includes a deep Low power, wake-up mode for low g activity detection multimode output first in, first out (FIFO), several activity 1.4 A instant on mode with adjustable threshold detection modes, and a method for capturing only the peak <0.1 A standby mode acceleration of over threshold events. Built in features for system level power savings Two additional lower power modes with interrupt driven, wake-up Autonomous interrupt processing without processor features are available for monitoring motion during periods of intervention inactivity. In wake-up mode, acceleration data can be averaged to Deep embedded FIFO to minimize host processor load obtain a low enough output noise to trigger on low g thresholds. In Ultralow power event monitoring detects impacts and wakes instant on mode, the ADXL372 consumes 1.4 A while continuously up fast enough to capture the transient events monitoring the environment for impacts. When an impact event Ability to capture and store peak acceleration values of that exceeds the internally set threshold is detected, the device events switches to normal operating mode fast enough to record the event. Adjustable, low g threshold activity and inactivity detection Wide supply range: 1.6 V to 3.5 V High g applications tend to experience acceleration content over Acceleration sample synchronization via external trigger a wide range of frequencies. The ADXL372 includes a 4-pole low- 2 SPI digital interface and limited I C interface format support pass antialiasing filter to attenuate out of band signals that are 12-bit output at 100 mg/LSB scale factor common in high g applications. The ADXL372 also incorporates Wide temperature range: 40C to +105C a high-pass filter to eliminate initial and slow changing errors, Small, thin, 3 mm 3.25 mm 1.06 mm package such as ambient temperature drift. APPLICATIONS The ADXL372 provides 12-bit output data at 100 mg/LSB scale factor. The user can access configuration and data registers via Impact and shock detection 2 the serial peripheral interface (SPI) or limited I C protocol. The Asset health assessment ADXL372 operates over a wide supply voltage range and is available Portable Internet of Things (IoT) edge nodes in a 3 mm 3.25 mm 1.06 mm package. Concussion and head trauma detection Multifunction pin names may be referenced by their relevant function only. FUNCTIONAL BLOCK DIAGRAM V V S DDI/O INT1 INT2 3-AXIS MEMS 12-BIT DIGITAL MOSI SENSOR ADC LOGIC, FIFO, MISO AND SPI CS SCLK 4-POLE AXIS ANTIALIASING DEMODULATORS ADXL372 FILTERS GND Figure 1. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20172018 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 15430-001ADXL372 Data Sheet TABLE OF CONTENTS Multibyte Transfers .................................................................... 26 Features .............................................................................................. 1 Invalid Addresses and Address Folding .................................. 27 Applications ....................................................................................... 1 Register Map ................................................................................... 30 General Description ......................................................................... 1 Register Details ............................................................................... 32 Functional Block Diagram .............................................................. 1 Analog Devices ID Register ...................................................... 32 Revision History ............................................................................... 3 Analog Devices MEMS ID Register ......................................... 32 Specifications ..................................................................................... 4 Device ID Register ..................................................................... 32 Absolute Maximum Ratings ............................................................ 6 Product Revision ID Register ................................................... 32 Thermal Resistance ...................................................................... 6 Status Register ............................................................................. 33 Recommended Soldering Profile ............................................... 6 Activity Status Register .............................................................. 33 ESD Caution .................................................................................. 6 FIFO Entries Register, MSB ...................................................... 34 Pin Configuration and Function Descriptions ............................. 7 FIFO Entries Register, LSB ........................................................ 34 Typical Performance Characteristics ............................................. 8 X-Axis Data Register, MSB ....................................................... 34 Theory of Operation ...................................................................... 13 X-Axis Data Register, LSB ......................................................... 34 Mechanical Device Operation .................................................. 13 Y-Axis Data Register, MSB ........................................................ 35 Operating Modes ........................................................................ 13 Y-Axis Data Register, LSB ......................................................... 35 Bandwidth ................................................................................... 13 Z-Axis Data Register, MSB ....................................................... 35 Power/Noise Trade-Off .............................................................. 14 Z-Axis Data Register, LSB ......................................................... 35 Power Savings ............................................................................. 15 Highest Peak Data Registers ..................................................... 36 Autonomous Event Detection ....................................................... 16 X-Axis Highest Peak Data Register, MSB ............................... 36 Activity and Inactivity................................................................ 16 X-Axis Highest Peak Data Register, LSB ................................. 36 Motion Warning ......................................................................... 18 Y-Axis Highest Peak Data Register, MSB ................................ 36 Impact Detection Features ............................................................ 19 Y-Axis Highest Peak Data Register, LSB ................................. 37 Wide Bandwidth ......................................................................... 19 Z-Axis Highest Peak Data Register, MSB ............................... 37 Instant On Impact Detection .................................................... 19 Z-Axis Highest Peak Data Register, LSB ................................. 37 Capturing Impact Events ........................................................... 19 Offset Trim Registers ................................................................. 38 FIFO ................................................................................................. 20 X-Axis Offset Trim Register, LSB ............................................. 38 Benefits of the FIFO ................................................................... 20 Y-Axis Offset Trim Register, LSB ............................................. 38 Using the FIFO ........................................................................... 20 Z-Axis Offset Trim Register, LSB ............................................. 38 Retrieving Data from FIFO ....................................................... 21 X-Axis Activity Threshold Register, MSB ............................... 39 Interrupts ......................................................................................... 22 X-Axis of Activity Threshold Register, LSB ............................ 39 Interrupt Pins .............................................................................. 22 Y-Axis Activity Threshold Register, MSB ............................... 39 Types of Interrupts ..................................................................... 22 Y-Axis of Activity Threshold Register, LSB ............................ 40 Additional Features ........................................................................ 24 Z-Axis Activity Threshold Register, MSB ............................... 40 Using an External Clock ............................................................ 24 Z-Axis of Activity Threshold Register, LSB ............................ 40 Synchronized Data Sampling .................................................... 24 Activity Time Register ............................................................... 41 Self Test ........................................................................................ 24 X-Axis Inactivity Threshold Register, MSB ............................ 41 User Register Protection ............................................................ 25 X-Axis of Inactivity Threshold Register, LSB ......................... 42 User Offset Trims ....................................................................... 25 Y-Axis Inactivity Threshold Register, MSB ............................ 42 Serial Communications ................................................................. 26 Y-Axis of Inactivity Threshold Register, LSB ......................... 43 Serial Interface ............................................................................ 26 Rev. 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