Datasheet ADXL372 (Analog Devices)

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 µA 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 µA 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 µA instant on mode with adjustable threshold
detection modes, and a method for capturing only the peak
<0.1 µA standby mode
acceleration of over threshold events.
Built in features for system level power savings Autonomous interrupt processing without processor
Two additional lower power modes with interrupt driven, wake-up
intervention
features are available for monitoring motion during periods of
Deep embedded FIFO to minimize host processor load
inactivity. In wake-up mode, acceleration data can be averaged to
Ultralow power event monitoring detects impacts and wakes
obtain a low enough output noise to trigger on low g thresholds. In
up fast enough to capture the transient events
instant on mode, the ADXL372 consumes 1.4 µA while continuously
Ability to capture and store peak acceleration values of
monitoring the environment for impacts. When an impact event
events
that exceeds the internal y set threshold is detected, the device
Adjustable, low g threshold activity and inactivity detection
switches to normal operating mode fast enough to record the event.
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-
SPI digital interface and limited I2C 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: −40°C to +105°C
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
Impact and shock detection
factor. The user can access configuration and data registers via
Asset health assessment
the serial peripheral interface (SPI) or limited I2C protocol. The
Portable Internet of Things (IoT) edge nodes
ADXL372 operates over a wide supply voltage range and is available
Concussion and head trauma detection
in a 3 mm × 3.25 mm × 1.06 mm package. Multifunction pin names may be referenced by their relevant function only.
FUNCTIONAL BLOCK DIAGRAM VS VDDI/O INT1 3-AXIS INT2 MEMS 12-BIT DIGITAL SENSOR MOSI ADC LOGIC, FIFO, MISO AND SPI CS SCLK AXIS 4-POLE DEMODULATORS ANTIALIASING ADXL372
001
FILTERS
15430-
GND
Figure 1.
Rev. 0 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 rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2017 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE RECOMMENDED SOLDERING PROFILE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION MECHANICAL DEVICE OPERATION OPERATING MODES Measurement Mode Instant On Mode Wake-Up Mode Standby BANDWIDTH Low-Pass Antialiasing Filter High-Pass Filter Filter Settling Time Selectable ODR POWER/NOISE TRADE-OFF POWER SAVINGS AUTONOMOUS EVENT DETECTION ACTIVITY AND INACTIVITY Low-Pass Activity Detect Filter Activity Detection Referenced and Absolute Configurations Activity Timer Activity Detection in Wake-Up Mode Inactivity Detection Referenced and Absolute Configurations Inactivity Timer Linking Activity and Inactivity Detection Default Mode Linked Mode Loop Mode Autosleep Using the AWAKE Bit MOTION WARNING IMPACT DETECTION FEATURES WIDE BANDWIDTH INSTANT ON IMPACT DETECTION CAPTURING IMPACT EVENTS FIFO BENEFITS OF THE FIFO System Level Power Savings Data Recording/Event Context USING THE FIFO FIFO Disabled Oldest Saved Mode (First N) Stream Mode (Last N) Triggered Mode RETRIEVING DATA FROM FIFO INTERRUPTS INTERRUPT PINS Alternate Functions TYPES OF INTERRUPTS Activity and Inactivity Interrupts Data Ready Interrupt FIFO Interrupts FIFO Watermark FIFO Ready Overrun ADDITIONAL FEATURES USING AN EXTERNAL CLOCK SYNCHRONIZED DATA SAMPLING SELF TEST Self Test Procedure USER REGISTER PROTECTION USER OFFSET TRIMS SERIAL COMMUNICATIONS SERIAL INTERFACE SPI Protocol I2C Protocol MULTIBYTE TRANSFERS INVALID ADDRESSES AND ADDRESS FOLDING SPI Timing Diagrams I2C Timing Diagrams REGISTER MAP REGISTER DETAILS ANALOG DEVICES ID REGISTER ANALOG DEVICES MEMS ID REGISTER DEVICE ID REGISTER PRODUCT REVISION ID REGISTER STATUS REGISTER ACTIVITY STATUS REGISTER FIFO ENTRIES REGISTER, MSB FIFO ENTRIES REGISTER, LSB X-AXIS DATA REGISTER, MSB X-AXIS DATA REGISTER, LSB Y-AXIS DATA REGISTER, MSB Y-AXIS DATA REGISTER, LSB Z-AXIS DATA REGISTER, MSB Z-AXIS DATA REGISTER, LSB HIGHEST PEAK DATA REGISTERS X-AXIS HIGHEST PEAK DATA REGISTER, MSB X-AXIS HIGHEST PEAK DATA REGISTER, LSB Y-AXIS HIGHEST PEAK DATA REGISTER, MSB Y-AXIS HIGHEST PEAK DATA REGISTER, LSB Z-AXIS HIGHEST PEAK DATA REGISTER, MSB Z-AXIS HIGHEST PEAK DATA REGISTER, LSB OFFSET TRIM REGISTERS X-AXIS OFFSET TRIM REGISTER, LSB Y-AXIS OFFSET TRIM REGISTER, LSB Z-AXIS OFFSET TRIM REGISTER, LSB X-AXIS ACTIVITY THRESHOLD REGISTER, MSB X-AXIS OF ACTIVITY THRESHOLD REGISTER, LSB Y-AXIS ACTIVITY THRESHOLD REGISTER, MSB Y-AXIS OF ACTIVITY THRESHOLD REGISTER, LSB Z-AXIS ACTIVITY THRESHOLD REGISTER, MSB Z-AXIS OF ACTIVITY THRESHOLD REGISTER, LSB ACTIVITY TIME REGISTER X-AXIS INACTIVITY THRESHOLD REGISTER, MSB X-AXIS OF INACTIVITY THRESHOLD REGISTER, LSB Y-AXIS INACTIVITY THRESHOLD REGISTER, MSB Y-AXIS OF INACTIVITY THRESHOLD REGISTER, LSB Z-AXIS INACTIVITY THRESHOLD REGISTER, MSB Z-AXIS OF INACTIVITY THRESHOLD REGISTER, LSB INACTIVITY TIME REGISTERS INACTIVITY TIMER REGISTER, MSB INACTIVITY TIMER REGISTER, LSB X-AXIS MOTION WARNING THRESHOLD REGISTER, MSB X-AXIS OF MOTION WARNING NOTIFICATION REGISTER, LSB Y-AXIS MOTION WARNING NOTIFICATION THRESHOLD REGISTER, MSB Y-AXIS OF MOTION WARNING NOTIFICATION REGISTER, LSB Z-AXIS MOTION WARNING NOTIFICATION THRESHOLD REGISTER, MSB Z-AXIS MOTION WARNING NOTIFICATION REGISTER, LSB HIGH-PASS FILTER SETTINGS REGISTER FIFO SAMPLES REGISTER FIFO CONTROL REGISTER INTERRUPT PIN FUNCTION MAP REGISTERS INT2 FUNCTION MAP REGISTER EXTERNAL TIMING CONTROL REGISTER MEASUREMENT CONTROL REGISTER POWER CONTROL REGISTER SELF TEST REGISTER RESET (CLEARS) REGISTER, PART IN STANDBY MODE FIFO ACCESS REGISTER APPLICATIONS INFORMATION APPLICATION EXAMPLES Power Supply Decoupling Using External Timing Triggers OPERATION AT VOLTAGES OTHER THAN 2.5 V OPERATION AT TEMPERATURES OTHER THAN AMBIENT MECHANICAL CONSIDERATIONS FOR MOUNTING AXES OF ACCELERATION SENSITIVITY LAYOUT AND DESIGN RECOMMENDATIONS OUTLINE DIMENSIONS ORDERING GUIDE