AD ADXL355BEZ-RL7 Hermetic package offers excellent long-term stability Datasheet

Low Noise, Low Drift, Low Power,
3-Axis MEMS Accelerometers
ADXL354/ADXL355
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
V1P8ANA
LDO
VSUPPLY
V1P8DIG
RANGE
POWER
MANAGEMENT
LDO
XOUT
ANALOG
FILTER
ST1
3-AXIS
SENSOR
OUT
TEMP
SENSOR
TEMP
CONTROL
LOGIC
ADXL354
VSSIO
ST2
STBY
VDDIO
14205-002
YOUT
VSS
Figure 1. ADXL354 Functional Block Diagram
V1P8ANA
LDO
VSUPPLY
V1P8DIG
LDO
VDDIO
ADXL355
POWER
MANAGEMENT
ADC
3-AXIS
SENSOR
ANALOG
FILTER
ADC
DIGITAL
FILTER
CONTROL
LOGIC
ADC
TEMP
SENSOR
ADC
FIFO
VSSIO
VSS
SERIAL
I/O
INT1
INT2
DRDY
CS/SCL
SCLK/VSSIO
MOSI/SDA
MISO/ASEL
14205-001
Hermetic package offers excellent long-term stability
0 g offset vs. temperature (all axes): 0.15 mg/°C maximum
Ultralow noise density (all axes): 20 μg/√Hz (ADXL354)
Low power, VSUPPLY (LDO enabled)
ADXL354 in measurement mode: 150 μA
ADXL355 in measurement mode: 200 μA
ADXL354/ADXL355 in standby mode: 21 μA
ADXL354 has user adjustable analog output bandwidth
ADXL355 digital output features
Digital serial peripheral interface (SPI)/I2C interfaces
20-bit analog-to-digital converter (ADC)
Data interpolation routine for synchronous sampling
Programmable high- and low-pass digital filters
Electromechanical self test
Integrated temperature sensor
Voltage range options
VSUPPLY with internal regulators: 2.25 V to 3.6 V
V1P8ANA, V1P8DIG with internal low dropout regulator (LDO)
bypassed: 1.8 V typical ± 10%
Operating temperature range: −40°C to +125°C
14-terminal, 6 mm × 6 mm × 2.1 mm, LCC package,
0.26 grams
Figure 2. ADXL355 Functional Block Diagram
APPLICATIONS
Inertial measurement units (IMUs)/altitude and heading
reference systems (AHRSs)
Platform stabilization systems
Structural health monitoring
Seismic imaging
Tilt sensing
Robotics
Condition monitoring
GENERAL DESCRIPTION
The analog output ADXL354 and the digital output ADXL355
are low noise density, low 0 g offset drift, low power, 3-axis
accelerometers with selectable measurement ranges. The
ADXL354B supports the ±2 g and ±4 g ranges, the ADXL354C
supports the ±2 g and ±8 g ranges, and the ADXL355 supports
the ±2.048 g, ±4.096 g, and ±8.192 g ranges. The ADXL354/
ADXL355 offer industry leading noise, minimal offset drift over
temperature, and long term stability enabling precision
applications with minimal calibration.
1
Highly integrated in a compact form factor, the low power
ADXL355 is ideal in an Internet of Things (IoT) sensor node
and other wireless product designs.
The ADXL355 multifunction pin names may be referenced by
their relevant function only for either the SPI or I2C interfaces.
Protected by U.S. Patents 8,472,270; 9,041,462; 8,665,627; 8,917,099; 6,892,576; 9,297,825; and 7,956,621.
Rev. 0
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©2016 Analog Devices, Inc. All rights reserved.
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Technical Support
ADXL354/ADXL355
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
NVM_BUSY ............................................................................... 28
Applications ....................................................................................... 1
External Synchronization and Interpolation .......................... 29
Functional Block Diagrams ............................................................. 1
ADXL355 Register Map ................................................................. 31
General Description ......................................................................... 1
Register Definitions........................................................................ 32
Revision History ............................................................................... 2
Analog Devices ID Register ...................................................... 32
Specifications..................................................................................... 3
Analog Devices MEMS ID Register......................................... 32
Analog Output for the ADXL354 ............................................... 3
Device ID Register ..................................................................... 32
Digital Output for the ADXL355 ............................................... 4
Product Revision ID Register ................................................... 32
SPI Digital Interface Characteristics for the ADXL355 .......... 5
Status Register ............................................................................. 32
2
I C Digital Interface Characteristics for the ADXL355 ........... 6
FIFO Entries Register ................................................................ 33
Absolute Maximum Ratings............................................................ 8
Temperature Data Registers ...................................................... 33
Thermal Resistance ...................................................................... 8
X-Axis Data Registers ................................................................ 33
ESD Caution .................................................................................. 8
Y-Axis Data Registers ................................................................ 34
Pin Configurations and Function Descriptions ........................... 9
Z-Axis Data Registers ................................................................ 34
Typical Performance Characteristics ........................................... 11
FIFO Access Register ................................................................. 35
Root Allan Variance (RAV) ADXL355 Characteristics ......... 19
X-Axis Offset Trim Registers .................................................... 35
Theory of Operation ...................................................................... 20
Y-Axis Offset Trim Registers .................................................... 35
Analog Output ............................................................................ 20
Z-Axis Offset Trim Registers .................................................... 36
Digital Output ............................................................................. 21
Activity Enable Register ............................................................ 36
Axes of Acceleration Sensitivity ............................................... 21
Activity Threshold Registers ..................................................... 36
Power Sequencing ...................................................................... 22
Activity Count Register ............................................................. 36
Power Supply Description ......................................................... 22
Filter Settings Register ............................................................... 37
Overrange Protection................................................................. 22
FIFO Samples Register .............................................................. 37
Self Test ........................................................................................ 22
Interrupt Pin (INTx) Function Map Register......................... 37
Filter ............................................................................................. 23
Data Synchronization ................................................................ 38
Serial Communications ................................................................. 25
I2C Speed, Interrupt Polarity, and Range Register ................. 38
SPI Protocol ................................................................................. 25
Power Control Register ............................................................. 38
I2C Protocol ................................................................................. 26
Self Test Register ......................................................................... 39
Reading Acceleration or Temperature Data from the Interface
....................................................................................................... 26
Reset Register .............................................................................. 39
Recommended Soldering Profile ................................................. 40
FIFO ................................................................................................. 27
PCB Footprint Pattern ............................................................... 41
Interrupts ......................................................................................... 28
Packaging and Ordering Information ......................................... 42
DATA_RDY................................................................................. 28
Outline Dimensions ................................................................... 42
DRDY Pin .................................................................................... 28
Branding Information................................................................ 42
FIFO_FULL ................................................................................. 28
Ordering Guide .......................................................................... 42
FIFO_OVR .................................................................................. 28
Activity ......................................................................................... 28
REVISION HISTORY
9/2016—Revision 0: Initial Version
Rev. 0 | Page 2 of 42
Data Sheet
ADXL354/ADXL355
SPECIFICATIONS
ANALOG OUTPUT FOR THE ADXL354
TA = 25°C, VSUPPLY = 3.3 V, x-axis acceleration and y-axis acceleration = 0 g, and z-axis acceleration = 1 g, unless otherwise noted.
Table 1.
Parameter
SENSOR INPUT
Output Full-Scale Range (FSR)
Resonant Frequency 1
Nonlinearity
Cross Axis Sensitivity
SENSITIVITY
Sensitivity at XOUT, YOUT, ZOUT
Sensitivity Change due to Temperature
0 g OFFSET
0 g Output for XOUT, YOUT, ZOUT
0 g Offset vs. Temperature (X-Axis, Y-Axis, and Z-Axis) 2
Repeatability 3
Vibration Rectification Error (VRE) 4
NOISE DENSITY
X-Axis, Y-Axis, and Z-Axis
Velocity Random Walk
BANDWIDTH
Internal Low-Pass Filter Frequency
SELF TEST
Output Change
X-Axis
Y-Axis
Z-Axis
POWER SUPPLY
Voltage Range
VSUPPLY 5
VDDIO
V1P8ANA, V1P8DIG with Internal Low Dropout
Regulator (LDO) Bypassed
Current
Measurement Mode
VSUPPLY (LDO Enabled)
V1P8ANA (LDO Disabled)
V1P8DIG (LDO Disabled)
Standby Mode
VSUPPLY (LDO Enabled)
V1P8ANA (LDO Disabled)
V1P8DIG (LDO Disabled)
Turn On Time 6
Test Conditions/Comments
Each axis
ADXL354B, supports two ranges
ADXL354C, supports two ranges
Min
Rev. 0 | Page 3 of 42
g
g
kHz
%
%
400
200
100
±0.01
432
216
108
mV/g
mV/g
mV/g
%/°C
−75
−0.15
±25
±0.1
±3.5
±9
<0.4
+75
+0.15
mg
mg/°C
mg
mg
g
Fixed frequency, 50% response
attenuation
2 g range
Power-off to standby
Unit
368
184
92
X-axis and y-axis
Z-axis
VSUPPLY = 0 V
Max
±2/±4
±2/±8
2.4
0.1
1
±2 g
Ratiometric to V1P8ANA
±2 g
±4 g
±8 g
−40°C to +125°C
Each axis, ±2 g
Referred to V1P8ANA/2
−40°C to +125°C
X-axis and y-axis
Z-axis
±2 g range, in a 1 g orientation,
offset due to 2.5 g rms vibration
±2 g
Typ
2.25
V1P8DIG
1.62
20
9
13
µg/√Hz
µm/sec/√Hr
µm/sec/√Hr
1500
Hz
0.3
0.3
1.5
g
g
g
2.5
2.5
1.8
3.6
3.6
1.98
V
V
V
150
138
12
µA
µA
µA
21
7
10
<10
<10
µA
µA
µA
ms
ms
ADXL354/ADXL355
Parameter
OUTPUT AMPLIFIER
Swing
Output Series Resistance
TEMPERATURE SENSOR
Output at 25°C
Scale Factor
TEMPERATURE
Operating Temperature Range
Data Sheet
Test Conditions/Comments
Min
No load
0.03
Typ
Max
Unit
V1P8ANA − 0.03
32
V
kΩ
892.2
3.0
mV
mV/°C
−40
+125
°C
The resonant frequency is a sensor characteristic. An integrated analog 1.5 kHz (−6 dB) sinc low-pass filter that cannot be bypassed limits the actual output response.
The temperature change is −40°C to +25°C or +25°C to +125°C.
3
Repeatability is predicted for a 10 year life and includes shifts due to the high temperature operating life test (HTOL) (TA = 150°C, VSUPPLY = 3.6 V, and 1000 hours),
temperature cycling (−55°C to +125°C and 1000 cycles), velocity random walk, broadband noise, and temperature hysteresis.
4
The VRE measurement is the shift in dc offset while the device is subject to 2.5 g rms of random vibration from 50 Hz to 2 kHz. The device under test (DUT) is
configured for the ±2 g range and an output data rate of 4 kHz. The VRE scales with the range setting.
5
When V1P8ANA and V1P8DIG are generated internally, VSUPPLY is valid. To disable the LDO and drive V1P8ANA and V1P8DIG externally, connect VSUPPLY to VSS.
6
Standby to measurement mode; valid when the output is within 1 mg of the final value.
1
2
DIGITAL OUTPUT FOR THE ADXL355
TA = 25°C, VSUPPLY = 3.3 V, x-axis acceleration and y-axis acceleration = 0 g, and z-axis acceleration = 1 g, and output data rate (ODR) =
500 Hz, unless otherwise noted. Note that multifunction pin names may be referenced by their relevant function only.
Table 2.
Parameter
SENSOR INPUT
Output Full Scale Range (FSR)
Test Conditions/Comments
Each axis
User selectable
Nonlinearity
Cross Axis Sensitivity
SENSITIVITY
X-Axis, Y-Axis, and Z-Axis Sensitivity
±2 g
X-Axis, Y-Axis, and Z-Axis Scale Factor
Sensitivity Change due to Temperature
0 g OFFSET
X-Axis, Y-Axis, and Z-Axis 0 g Output
0 g Offset vs. Temperature (X-Axis, Y-Axis, and Z-Axis) 1
Repeatability 2
Vibration Rectification 3
NOISE DENSITY
X-Axis, Y-Axis, and Z-Axis
Velocity Random Walk
OUTPUT DATA RATE AND BANDWIDTH
Low-Pass Filter Passband Frequency
High-Pass Filter Passband Frequency When Enabled
(Disabled by Default)
Each axis
±2 g
±4 g
±8 g
±2 g
±4 g
±8 g
−40°C to +125°C
Each axis, ±2 g
−40°C to +125°C
X-axis and y-axis
Z-axis
±2 g range, in a 1 g orientation,
offset due to 2.5 g rms vibration
±2 g
Min
Rev. 0 | Page 4 of 42
Max
Unit
g
g
g
% FS
%
±2.048
±4.096
±8.192
0.1
1
235,520
117,760
58,880
256,000
128,000
64,000
3.9
7.8
15.6
±0.01
276,480
138,240
69,120
LSB/g
LSB/g
LSB/g
µg/LSB
µg/LSB
µg/LSB
%/°C
−75
−0.15
±25
±0.02
±3.5
±9
<0.4
+75
+0.15
mg
mg/°C
mg
mg
g
25
9
13
X-axis and y-axis
Z-axis
User programmable, Register 0x28
User programmable, Register 0x28
for 4 kHz ODR
Typ
1
0.0095
µg/√Hz
µm/sec/√Hr
µm/sec/√Hr
1000
10
Hz
Hz
Data Sheet
ADXL354/ADXL355
Parameter
SELF TEST
Output Change
X-Axis
Y-Axis
Z-Axis
POWER SUPPLY
Voltage Range
VSUPPLY Operating 4
VDDIO
V1P8ANA and V1P8DIG with Internal LDO Bypassed
Current
Measurement Mode
VSUPPLY (LDO Enabled)
V1P8ANA (LDO Disabled)
V1P8DIG (LDO Disabled)
Standby Mode
VSUPPLY (LDO Enabled)
V1P8ANA (LDO Disabled)
V1P8DIG (LDO Disabled)
Turn On Time 5
Test Conditions/Comments
Min
Typ
Max
g
g
g
0.3
0.3
1.5
VSUPPLY = 0 V
2.25
V1P8DIG
1.62
2 g range
Power-off to standby
TEMPERATURE SENSOR
Output at 25°C
Scale Factor
TEMPERATURE
Operating Temperature Range
2.5
2.5
1.8
Unit
3.6
3.6
1.98
V
V
V
200
160
35.5
µA
µA
µA
21
7
10
<10
<10
µA
µA
µA
ms
ms
1852
−9.05
LSB
LSB/°C
−40
+125
°C
The temperature change is −40°C to +25°C or +25°C to +125°C.
Repeatability is predicted for a 10 year life and includes shifts due to the HTOL (TA = 150°C, VSUPPLY = 3.6 V, and 1000 hours), temperature cycling (−55°C to +125°C and
1000 cycles), velocity random walk, broadband noise, and temperature hysteresis.
3
The VRE measurement is the shift in dc offset while the device is subject to 2.5 g rms random vibration from 50 Hz to 2 kHz. The DUT is configured for the ±2 g range
and an output data rate of 4 kHz. The VRE scales with the range setting.
4
When V1P8ANA and V1P8DIG are generated internally, VSUPPLY is valid. To disable the LDO and drive V1P8ANA and V1P8DIG externally, connect VSUPPLY to VSS.
5
Standby to measurement mode; valid when the output is within 1 mg of final value.
1
2
SPI DIGITAL INTERFACE CHARACTERISTICS FOR THE ADXL355
Note that multifunction pin names may be referenced by their relevant function only.
Table 3.
Parameter
DC INPUT LEVELS
Input Voltage
Low Level
High Level
Input Current
Low Level
High Level
DC OUTPUT LEVELS
Output Voltage
Low Level
High Level
Output Current
Low Level
High Level
Symbol
Test Conditions/Comments
VIL
VIH
Min
Typ
Max
Unit
0.3 × VDDIO
V
V
0.7 × VDDIO
IIL
IIH
VIN = 0 V
VIN = VDDIO
VOL
VOH
IOL = IOL, MIN
IOH = IOH, MAX
IOL
IOH
VOL = VOL, MAX
VOH = VOH, MIN
−0.1
0.1
0.2 × VDDIO
0.8 × VDDIO
−10
4
Rev. 0 | Page 5 of 42
µA
µA
V
V
mA
mA
ADXL354/ADXL355
Data Sheet
Parameter
AC INPUT LEVELS
SCLK Frequency
SCLK High Time
SCLK Low Time
CS Setup Time
CS Hold Time
CS Disable Time
Rising SCLK Setup Time
MOSI Setup Time
MOSI Hold Time
AC OUTPUT LEVELS
Propagation Delay
Enable MISO Time
Disable MISO Time
Symbol
Test Conditions/Comments
Min
Typ
0.1
40
40
20
20
40
20
20
20
tHIGH
tLOW
tCSS
tCSH
tCSD
tSCLKS
tSU
tHD
tP
tEN
tDIS
CLOAD = 30 pF
Max
Unit
10
MHz
ns
ns
ns
ns
ns
ns
ns
ns
30
ns
ns
ns
30
20
tCSD
CS
tCSS
tHIGH
tCSH
tLOW
tSCLKS
SCLK
tSU
tHD
MOSI
tDIS
tP
14205-003
tEN
MISO
Figure 3. SPI Interface Timing Diagram
I2C DIGITAL INTERFACE CHARACTERISTICS FOR THE ADXL355
Note that multifunction pin names may be referenced by their relevant function only.
Table 4.
Parameter
DC INPUT LEVELS
Input Voltage
Low Level
High Level
Hysteresis of Schmitt
Trigger Inputs
Input Current
DC OUTPUT LEVELS
Output Voltage
Low Level
Output Current
Low Level
Symbol
Test Conditions/
Comments
VIL
VIH
VHYS
IIL
VOL1
VOL2
IOL
Min
I2C_HS = 0 (Fast Mode)
Typ Max
I2C_HS = 1 (High Speed Mode)
Min
Typ
Max
0.3 × VDDIO
0.7 × VDDIO
0.05 × VDDIO
0.1 × VDDIO < VIN <
0.9 × VDDIO
−10
IOL = 3 mA
VDD > 2 V
VDD ≤ 2 V
VOL = 0.4 V
VOL = 0.6 V
20
6
Rev. 0 | Page 6 of 42
0.3 × VDDIO
0.7 × VDDIO
0.1 × VDDIO
Unit
V
V
μA
+10
μA
0.4
0.2 × VDDIO
V
V
mA
mA
Data Sheet
ADXL354/ADXL355
Parameter
AC INPUT LEVELS
SCLK Frequency
SCL High Time
SCL Low Time
Start Setup Time
Start Hold Time
SDA Setup Time
SDA Hold Time
Stop Setup Time
Bus Free Time
SCL Input Rise Time
SCL Input Fall Time
SDA Input Rise Time
SDA Input Fall Time
Width of Spikes to
Suppress
AC OUTPUT LEVELS
Propagation Delay
Data
Acknowledge
Output Fall Time
Symbol
tHIGH
tLOW
tSUSTA
tHDSTA
tSUDAT
tHDDAT
tSUSTO
tBUF
tRCL
tFCL
tRDA
tFDA
tSP
Test Conditions/
Comments
Min
I2C_HS = 0 (Fast Mode)
Typ Max
0
260
500
260
260
50
0
260
500
I2C_HS = 1 (High Speed Mode)
Min
Typ
Max
1
0
60
160
160
160
10
0
160
3.4
120
120
120
120
50
Not shown in Figure 4
Unit
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
80
80
160
160
10
CLOAD = 500 pF
tVDDAT
tVDACK
tF
97
Not shown in Figure 4
450
450
120
20 × (VDD/5.5)
27
tFDA
135
tRDA
ns
ns
ns
tBUF
SDA
tVDDAT
tSUDAT
tHDDAT
tLOW
tVDDAT
SCL
Figure 4. I2C Interface Timing Diagram
Rev. 0 | Page 7 of 42
tVDACK
tFCL
tHIGH
tRCL
tSUSTO
tSUSTA
14205-004
tSUSTA tHDSTA
ADXL354/ADXL355
Data Sheet
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 5.
Parameter
Acceleration (Any Axis, 0.1 ms)
Unpowered
VSUPPLY, VDDIO
V1P8ANA, V1P8DIG Configured as Inputs
ADXL354
Digital Inputs (RANGE, ST1, ST2, STBY)
Analog Outputs (XOUT, YOUT, ZOUT, TEMP)
ADXL355
Digital Pins (CS, SCLK, MOSI, MISO,
INT1, INT2, DRDY)
Operating Temperature Range
Storage Temperature Range
Thermal performance is directly linked to printed circuit board
(PCB) design and operating environment. Careful attention to
PCB thermal design is required.
Rating
5,000 g
5.4 V
1.98 V
Table 6. Thermal Resistance
−0.3 V to VDDIO + 0.3 V
−0.3 V to V1P8ANA + 0.3 V
−0.3 V to VDDIO + 0.3 V
Package Type
E-14-11
1
θJA
42
Unit
°C/W
Thermal impedance simulated values are based on a JEDEC 2S2P thermal
test board with four thermal vias. See JEDEC JESD51.
ESD CAUTION
−40°C to +125°C
−55°C to +150°C
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
Rev. 0 | Page 8 of 42
Data Sheet
ADXL354/ADXL355
12 X OUT
Y
11 VSUPPLY
RANGE 1
ST1 2
ADXL354
10 V1P8ANA
ST2 3
TOP VIEW
(Not to Scale)
9
VSS
8
V1P8DIG
Z
STBY 7
VSSIO 6
VDDIO 5
TEMP 4
X
14205-007
13 Y OUT
14 ZOUT
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 5. ADXL354 Pin Configuration
Table 7. ADXL354 Pin Function Descriptions
Pin No.
1
Mnemonic
RANGE
2
3
4
5
6
7
ST1
ST2
TEMP
VDDIO
VSSIO
STBY
8
V1P8DIG
9
10
VSS
V1P8ANA
11
VSUPPLY
12
13
14
XOUT
YOUT
ZOUT
Description
Range Selection Pin. Set this pin to ground to select the ±2 g range, or set this pin to VDDIO to select the ±4 g
or ±8 g range. This pin is model dependent (see the Ordering Guide section).
Self Test Pin 1. This pin enables self test mode.
Self Test Pin 2. This pin activates the electromechanical self test actuation.
Temperature Sensor Output.
Digital Interface Supply Voltage.
Digital Ground.
Standby or Measurement Mode Selection Pin. Set this pin to ground to enter standby mode, or set this pin
to VDDIO to enter measurement mode.
Digital Supply. This pin requires a decoupling capacitor. If VSUPPLY connects to VSS, supply the voltage to this
pin externally.
Analog Ground.
Analog Supply. This pin requires a decoupling capacitor. If VSUPPLY connects to VSS, supply the voltage to this
pin externally.
Supply Voltage. When VSUPPLY equals 2.25 V to 3.6 V, VSUPPLY enables the internal LDOs to generate V1P8DIG and
V1P8ANA. For VSUPPLY = VSS, V1P8DIG and V1P8ANA are externally supplied.
X-Axis Output.
Y-Axis Output.
Z-Axis Output.
Rev. 0 | Page 9 of 42
12 INT1
Y
11 VSUPPLY
CS/SCL 1
SCLK/VSSIO 2
ADXL355
10 V1P8ANA
MOSI/SDA 3
TOP VIEW
(Not to Scale)
9
VSS
8
V1P8DIG
X
Z
RESERVED 7
VSSIO 6
VDDIO 5
MISO/ASEL 4
14205-006
13 INT2
Data Sheet
14 DRDY
ADXL354/ADXL355
Figure 6. ADXL355 Pin Configuration
Table 8. ADXL355 Pin Function Descriptions
Pin No.
1
Mnemonic
CS/SCL
2
SCLK/VSSIO
3
MOSI/SDA
4
MISO/ASEL
5
6
7
8
VDDIO
VSSIO
RESERVED
V1P8DIG
9
10
VSS
V1P8ANA
11
VSUPPLY
12
13
14
INT1
INT2
DRDY
Description
Chip Select for SPI (CS).
Serial Communications Clock for I2C (SCL).
Serial Communications Clock for SPI (SCLK).
Connect to VSSIO for I2C (VSSIO).
Master Output, Slave Input for SPI (MOSI).
Serial Data for I2C (SDA).
Master Input, Slave Output for SPI (MISO).
Alternate I2C Address Select for I2C (ASEL).
Digital Interface Supply Voltage.
Digital Ground.
Reserved. This pin can be connected to ground or left open.
Digital Supply. This pin requires a decoupling capacitor. If VSUPPLY connects to VSS, supply the voltage to this
pin externally.
Analog Ground.
Analog Supply. This pin requires a decoupling capacitor. If VSUPPLY connects to VSS, supply the voltage to this
pin externally.
Supply Voltage. When VSUPPLY equals 2.25 V to 3.6 V, VSUPPLY enables the internal LDOs to generate V1P8DIG and
V1P8ANA. For VSUPPLY = VSS, V1P8DIG and V1P8ANA are externally supplied.
Interrupt Pin 1.
Interrupt Pin 2.
Data Ready Pin.
Rev. 0 | Page 10 of 42
Data Sheet
ADXL354/ADXL355
TYPICAL PERFORMANCE CHARACTERISTICS
All figures include data for multiple devices and multiple lots, and they were taken in the ±2 g range, unless otherwise noted.
1
10
XOUT (g)
1
0.1
100
1000
FREQUENCY (Hz)
0.01
10
14205-207
0.01
10
Figure 7. ADXL354 Frequency Response for X-Axis
100
1000
FREQUENCY (Hz)
14205-210
0.1
Figure 10. ADXL355 Normalized Frequency Response for X-Axis at 4 kHz ODR
10
1
Y-AXIS (g)
YOUT (g)
1
0.1
1000
FREQUENCY (Hz)
Figure 8. ADXL354 Frequency Response for Y-Axis
0.01
10
Figure 11. ADXL355 Normalized Frequency Response for Y-Axis at 4 kHz ODR
Z-AXIS (g)
1
1
100
1000
FREQUENCY (Hz)
14205-209
ZOUT (g)
1000
FREQUENCY (Hz)
10
0.1
10
100
14205-211
100
0.1
0.01
10
100
FREQUENCY (Hz)
Figure 9. ADXL354 Frequency Response for Z-Axis
1000
14205-212
0.01
10
14205-208
0.1
Figure 12. ADXL355 Normalized Frequency Response for Z-Axis at 4 kHz ODR
Rev. 0 | Page 11 of 42
ADXL354/ADXL355
15.00
Data Sheet
1.00
MAXIMUM CHANGE = 1.69mg
AVERAGE CHANGE = 1.18mg
RELATIVE SENSITIVITY (%)
RELATIVE OFFSET (mg)
10.00
5.00
0
MAXIMUM CHANGE = 0.60%
AVERAGE CHANGE = 0.34%
0.50
0
–5.00
55
105
TEMPERATURE (°C)
–0.65
–45
14205-213
5
105
Figure 16. ADXL354 X-Axis Sensitivity Relative to 25°C vs. Temperature
1.00
MAXIMUM CHANGE = 3.12mg
AVERAGE CHANGE = 1.85mg
RELATIVE SENSITIVITY (%)
10.00
RELATIVE OFFSET (mg)
55
TEMPERATURE (°C)
Figure 13. ADXL354 X-Axis Zero g Offset Relative to 25°C vs. Temperature
15.00
5
14205-216
–0.50
–9.75
–45
5.00
0
MAXIMUM CHANGE = 0.54%
AVERAGE CHANGE = 0.28%
0.50
0
–5.00
55
105
TEMPERATURE (°C)
–0.65
–45
14205-214
5
105
Figure 17. ADXL354 Y-Axis Sensitivity Relative to 25°C vs. Temperature
1.00
MAXIMUM CHANGE = 3.12mg
AVERAGE CHANGE = 1.85mg
RELATIVE SENSITIVITY (%)
10.00
RELATIVE OFFSET (mg)
55
TEMPERATURE (°C)
Figure 14. ADXL354 Y-Axis Zero g Offset Relative to 25°C vs. Temperature
15.00
5
14205-217
–0.50
–9.75
–45
MAXIMUM CHANGE = 0.99%
AVERAGE CHANGE = 0.51%
0.50
5.00
0
0
–5.00
55
TEMPERATURE (°C)
105
–0.65
–40
14205-215
5
10
60
TEMPERATURE (°C)
Figure 15. ADXL354 Z-Axis Zero g Offset Relative to 25°C vs. Temperature
110
14205-218
–0.50
–9.75
–45
Figure 18. ADXL354 Z-Axis Sensitivity Relative to 25°C vs. Temperature
Rev. 0 | Page 12 of 42
ADXL354 2g OFFSET Z-AXIS (g)
30
20
10
0
0
ADXL354 2g SENSITIVITY X-AXIS (V/g)
Figure 19. ADXL354 Zero g Offset Histogram at 25°C, X-Axis
80
70
70
60
60
50
40
30
20
10
10
0
0
ADXL354 2g SENSITIVITY Y-AXIS (V/g)
Figure 20. ADXL354 Zero g Offset Histogram at 25°C, Y-Axis
45
40
25
20
15
5
0
0
ADXL354 2g SENSITIVITY Z-AXIS (V/g)
Figure 21. ADXL354 Zero g Offset Histogram at 25°C, Z-Axis
Figure 24. ADXL354 Sensitivity Histogram at 25°C, Z-Axis
Rev. 0 | Page 13 of 42
14205-222
40
14205-223
70
0.368
0.370
0.372
0.374
0.376
0.378
0.380
0.382
0.384
0.386
0.388
0.390
0.392
0.394
0.396
0.398
0.400
0.402
0.404
0.406
0.408
0.410
0.412
0.414
0.416
0.418
0.420
0.422
0.424
0.426
0.428
0.430
0.432
50
HITS PER BIN (Count)
60
0.368
0.370
0.372
0.374
0.376
0.378
0.380
0.382
0.384
0.386
0.388
0.390
0.392
0.394
0.396
0.398
0.400
0.402
0.404
0.406
0.408
0.410
0.412
0.414
0.416
0.418
0.420
0.422
0.424
0.426
0.428
0.430
0.432
80
HITS PER BIN (Count)
14205-219
80
14205-224
ADXL354 2g OFFSET Y-AXIS (g)
14205-220
10
0.075
0.070
0.065
0.060
0.055
0.050
0.045
–0.040
–0.035
–0.030
–0.025
–0.020
–0.015
–0.010
–0.005
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
0.060
0.065
0.070
0.075
HITS PER BIN (Count)
70
0.368
0.370
0.372
0.374
0.376
0.378
0.375
0.377
0.379
0.381
0.383
0.385
0.387
0.389
0.391
0.393
0.395
0.397
0.399
0.401
0.403
0.405
0.407
0.409
0.416
0.418
0.420
0.422
0.424
0.426
0.428
0.430
0.432
30
HITS PER BIN (Count)
20
0.075
0.070
0.065
0.060
0.055
0.050
0.045
–0.040
–0.035
–0.030
–0.025
–0.020
–0.015
–0.010
–0.005
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
0.060
0.065
0.070
0.075
HITS PER BIN (Count)
ADXL354 2g OFFSET X-AXIS (g)
14205-221
HITS PER BIN (Count)
Data Sheet
ADXL354/ADXL355
60
50
40
30
20
Figure 22. ADXL354 Sensitivity Histogram at 25°C, X-Axis
50
40
30
Figure 23. ADXL354 Sensitivity Histogram at 25°C, Y-Axis
70
35
60
50
40
30
10
20
10
Data Sheet
0.68
0.6
0.58
0.5
0.48
0.4
0.3
0.18
0.1
0.08
0
1
2
3
4
INPUT VIBRATION (g rms)
–0.02
4
6
8
10
0
–0.1
–0.1
–0.3
–0.4
–0.2
–0.3
–0.4
–0.5
–0.5
–0.6
–0.6
2
INPUT VIBRATION (g rms)
3
4
–0.7
–0.1
–0.1
–0.2
–0.2
OFFSET SHIFT (g)
0
–0.3
–0.4
–0.6
INPUT VIBRATION (g rms)
14205-227
–0.6
4
8
10
–0.4
–0.5
3
6
–0.3
–0.5
2
4
Figure 29. ADXL354 Vibration Rectification Error (VRE),
Y-Axis Offset from +1 g, ±8 g Range, Y-Axis Orientation = +1 g
0
1
2
INPUT VIBRATION (g rms)
Figure 26. ADXL354 Vibration Rectification Error (VRE),
Y-Axis Offset from +1 g, ±2 g Range, Y-Axis Orientation = +1 g
0
0
–0.7
0
2
4
6
8
10
INPUT VIBRATION (g rms)
Figure 30. ADXL354 Vibration Rectification Error (VRE),
Z-Axis Offset from +1 g, ±8 g Range, Z-Axis Orientation = +1 g
Figure 27. ADXL354 Vibration Rectification Error (VRE),
Z-Axis Offset from +1 g, ±2 g Range, Z-Axis Orientation = +1 g
Rev. 0 | Page 14 of 42
14205-230
1
14205-226
0
14205-229
OFFSET SHIFT (g)
–0.2
–0.7
2
Figure 28. ADXL354 Vibration Rectification Error (VRE),
X-Axis Offset from +1 g, ±8 g Range, X-Axis Orientation = −1 g
0
–0.7
0
INPUT VIBRATION (g rms)
Figure 25. ADXL354 Vibration Rectification Error (VRE),
X-Axis Offset from +1 g, ±2 g Range, X-Axis Orientation = −1 g
OFFSET SHIFT (g)
0.28
0.2
0
OFFSET SHIFT (g)
0.38
14205-228
OFFSET SHIFT (g)
0.7
14205-225
OFFSET SHIFT (g)
ADXL354/ADXL355
Data Sheet
15.00
ADXL354/ADXL355
1.00
MAXIMUM DELTA = 6.5mg
AVERAGE DELTA = 1.7mg
RELATIVE SENSITIVITY (%)
RELATIVE OFFSET (mg)
10.00
5.00
0
MAXIMUM CHANGE = 0.78%
AVERAGE CHANGE = 0.72%
0.50
0
–5.00
55
105
TEMPERATURE (°C)
–0.65
–45
14205-231
5
105
Figure 34. ADXL355 X-Axis Sensitivity Relative to 25°C vs. Temperature
1.00
MAXIMUM DELTA = 3.2mg
AVERAGE DELTA = 1.4mg
RELATIVE SENSTIVITY (%)
10.00
RELATIVE OFFSET (mg)
55
TEMPERATURE (°C)
Figure 31. ADXL355 X-Axis Zero g Offset Relative to 25°C vs. Temperature
15.00
5
5.00
0
14205-234
–0.50
–9.75
–45
MAXIMUM CHANGE = 0.78%
AVERAGE CHANGE = 0.72%
0.50
0
–5.00
55
105
TEMPERATURE (°C)
–0.65
–45
14205-232
5
105
TEMPERATURE (°C)
Figure 32. ADXL355 Y-Axis Zero g Offset Relative to 25°C vs. Temperature
15.00
55
5
14205-235
–0.50
–9.75
–45
Figure 35. ADXL355 Y-Axis Sensitivity Relative to 25°C vs. Temperature
1.00
MAXIMUM DELTA = 10.6mg
AVERAGE DELTA = 5.3mg
MAXIMUM CHANGE = 0.47%
AVERAGE CHANGE = 0.3%
RELATIVE SENSTIVITY (%)
RELATIVE OFFSET (mg)
10.00
5.00
0
0.50
0
–5.00
5
55
TEMPERATURE (°C)
105
–0.65
–45
14205-233
–9.75
–45
5
55
TEMPERATURE (°C)
Figure 33. ADXL355 Z-Axis Zero g Offset Relative to 25°C vs. Temperature
105
14205-236
–0.50
Figure 36. ADXL355 Z-Axis Sensitivity Relative to 25°C vs. Temperature
Rev. 0 | Page 15 of 42
0
OFFSET (mg)
10
0
Figure 37. ADXL355 Zero g Offset Histogram at 25°C, X-Axis
SENSITIVITY (lsb/g)
80
70
50
40
30
10
0
Figure 38. ADXL355 Zero g Offset Histogram at 25°C, Y-Axis
SENSITIVITY (LSB/g)
45
40
25
20
15
10
0
Figure 39. ADXL355 Zero g Offset Histogram at 25°C, Z-Axis
Figure 42. ADXL355 Sensitivity Histogram at 25°C, Z-Axis
SENSITIVITY (LSB/g)
Rev. 0 | Page 16 of 42
14205-240
20
14205-241
30
14205-242
40
235520
237158
238797
240435
242074
243712
245350
246989
248627
250266
251904
253542
255181
256819
258458
260096
261734
263373
265011
266650
268288
269926
271565
273203
274842
276480
50
HITS PER BIN (Count)
70
235520
237158
238797
240435
242074
243712
245350
246989
248627
250266
251904
253542
255181
256819
258458
260096
261734
263373
265011
266650
268288
269926
271565
273203
274842
276480
60
HITS PER BIN (Count)
14205-237
–75
–69
–63
–57
–51
–45
–39
–33
–27
–21
–15
–9
–3
3
9
15
21
27
33
39
45
51
57
63
69
75
HITS PER BIN (Count)
80
235520
237158
238797
240435
242074
243712
245350
246989
248627
250266
251904
253542
255181
256819
258458
260096
261734
263373
265011
266650
268288
269926
271565
273203
274842
276480
30
HITS PER BIN (Count)
OFFSET (mg)
14205-238
OFFSET (mg)
14205-239
0
–75
–69
–63
–57
–51
–45
–39
–33
–27
–21
–15
–9
–3
3
9
15
21
27
33
39
45
51
57
63
69
75
HITS PER BIN (Count)
0
–75
–69
–63
–57
–51
–45
–39
–33
–27
–21
–15
–9
–3
3
9
15
21
27
33
39
45
51
57
63
69
75
HITS PER BIN (Count)
ADXL354/ADXL355
Data Sheet
60
60
50
40
30
20
10
Figure 40. ADXL355 Sensitivity Histogram at 25°C, X-Axis
60
50
40
30
20
20
10
Figure 41. ADXL355 Sensitivity Histogram at 25°C, Y-Axis
60
35
50
40
30
20
5
10
ADXL354/ADXL355
0.68
0.6
0.58
0.5
0.48
OFFSET SHIFT (g)
0.7
0.3
0.38
0.28
0.2
0.18
0.1
0.08
0
1
2
3
4
INPUT VIBRATION (g rms)
–0.02
8
10
–0.1
–0.2
OFFSET SHIFT (g)
–0.3
–0.4
–0.5
–0.2
–0.3
–0.4
–0.5
–0.6
–0.6
1
2
3
4
INPUT VIBRATION (g rms)
–0.7
14205-244
0
–0.1
–0.1
–0.2
–0.2
OFFSET SHIFT (g)
0
–0.3
–0.4
–0.6
INPUT VIBRATION (g rms)
14205-245
–0.6
4
8
10
–0.4
–0.5
3
6
–0.3
–0.5
2
4
Figure 47. ADXL355 Vibration Rectification Error (VRE),
Y-Axis Offset from +1 g, ±8 g Range, Y-Axis Orientation = +1 g
0
1
2
INPUT VIBRATION (g rms)
Figure 44. ADXL355 Vibration Rectification Error (VRE),
Y-Axis Offset from +1 g, ±2 g Range, Y-Axis Orientation = +1 g
0
0
14205-247
OFFSET CHANGE (g)
6
0
–0.1
OFFSET CHANGE (g)
4
Figure 46. ADXL355 Vibration Rectification Error (VRE),
X-Axis Offset from +1 g, ±8 g Range, X-Axis Orientation = −1 g
0
–0.7
2
INPUT VIBRATION (g rms)
Figure 43. ADXL355 Vibration Rectification Error (VRE),
X-Axis Offset from +1 g, ±2 g Range, X-Axis Orientation = −1 g
–0.7
0
Figure 45. ADXL355 Vibration Rectification Error (VRE),
Z-Axis Offset from +1 g, ±2 g Range, Z-Axis Orientation = +1 g
–0.7
0
2
4
6
8
10
INPUT VIBRATION (g rms)
Figure 48. ADXL355 Vibration Rectification Error (VRE),
Z-Axis Offset from +1 g, ±8 g Range, Z-Axis Orientation = +1 g
Rev. 0 | Page 17 of 42
14205-248
0
14205-246
0.4
14205-243
OFFSET CHANGE (g)
Data Sheet
1.15
0.002
1.05
0
0.95
–0.002
–0.004
0.85
10
60
110
–0.006
TEMPERATURE (°C)
Figure 49. ADXL354 Temperature Sensor Output and Linearity Offset vs.
Temperature
2100
4
1900
1700
–2
1300
–4
1100
900
700
–40
–6
TEMPERATURE SENSOR OUTPUT
LINEARITY
10
60
110
–8
TEMPERATURE (°C)
Figure 52. ADXL355 Temperature Sensor Output and Linearity Offset vs.
Temperature
100
90
70
80
HITS PER BIN (Count)
60
50
40
30
20
70
60
50
40
30
20
10
14205-251
10
0 125 129 133 137 141 145 149 153 157 161 165 169 173
TOTAL SUPPLY CURRENT (µA)
Figure 50. ADXL354 Total Supply Current, 3.3 V
30
25
20
15
10
ADXL355 CLOCK FREQUENCY (Hz)
14205-252
5
3800 3840 3880 3920 3960 4000 4040 4080 4120 4160 4200
0
180 184 188 192 196 200 204 208 212 216 220 224 228
TOTAL SUPPLY CURRENT (µA)
Figure 53. ADXL355 Total Supply Current, 3.3 V
35
HITS PER BIN (Count)
0
1500
80
0
2
Figure 51. ADXL355 Internal Clock Frequency Histogram
Rev. 0 | Page 18 of 42
14205-253
0.75
–40
6
14205-250
0.004
2300
ADXL355 TEMPERATURE SENSOR
LINEAR OFFSET (LSB)
1.25
ADXL354 TEMPERATURE SENSOR
LINEAR OFFSET (V)
0.006
TEMPERATURE SENSOR OUTPUT
LINEARITY
ADXL355 TEMPERATURE SENSOR OUTPUT (LSB)
Data Sheet
14205-249
1.35
HITS PER BIN (Count)
ADXL354 TEMPERATURE SENSOR OUTPUT (V)
ADXL354/ADXL355
Data Sheet
ADXL354/ADXL355
ROOT ALLAN VARIANCE (RAV) ADXL355 CHARACTERISTICS
All figures include data for multiple devices and multiple lots, and they were taken in the ±2 g range, unless otherwise noted.
1000
100
100
RAV (µg)
RAV (µg)
1000
10
0.1
1
10
100
1000
INTEGRATION TIME (Seconds)
Figure 54. ADXL355 Root Allan Variance (RAV), X-Axis
RAV (µg)
100
1
10
100
INTEGRATION TIME (Seconds)
1000
14205-255
10
0.1
0.1
1
10
100
1000
INTEGRATION TIME (Seconds)
Figure 56. ADXL355 Root Allan Variance (RAV), Z-Axis
1000
1
0.01
1
0.01
Figure 55. ADXL355 Root Allan Variance (RAV), Y-Axis
Rev. 0 | Page 19 of 42
14205-256
1
0.01
14205-254
10
ADXL354/ADXL355
Data Sheet
THEORY OF OPERATION
VDDIO (±4g, ±8g)
GND ( ± 2g)
0.1µF
11 VSUPPLY
RANGE 1
10 V1P8ANA
ST1 2
ST2 3
2.25V TO 3.6V
0.1µF
ADXL354
STBY 7
VSSIO 6
VDDIO 5
TEMP 4
9
VSS
8
V1P8DIG
ADC VREF
VDDIO (MEASUREMENT)
GND (STANDBY)
1µF
1µF
0.1µF
0.1µF
2.25V TO 3.6V
Figure 57. ADXL354 Application Circuit
Rev. 0 | Page 20 of 42
1µF
1µF
14205-022
The ADXL355 includes antialias filters before and after the high
resolution Σ-Δ ADC. User-selectable output data rates and filter
corners are provided. The temperature sensor is digitized with a
12-bit successive approximation register (SAR) ADC.
The ADXL354 outputs two forms of filtering: internal antialiasing filtering with a cutoff frequency of approximately 1.5 kHz,
and external filtering. The external filter uses a fixed, on-chip,
32 kΩ resistance in series with each output in conjunction with
the external capacitors to implement the low-pass filter antialiasing
and noise reduction prior to the external ADC. The antialias
filter cutoff frequency must be significantly higher than the
desired signal bandwidth. If the antialias filter corner is too low,
ratiometricity can be degraded where the signal attenuation is
different than the reference attenuation.
12 XOUT
The analog accelerometer outputs of the ADXL354 are ratiometric
to V1P8ANA; therefore, carefully digitize them correctly. The
temperature sensor output is not ratiometric. The XOUT, YOUT,
and ZOUT analog outputs are filtered internally with an antialiasing filter. These analog outputs also have an internal 32 kΩ
series resistor that can be used with an external capacitor to set
the bandwidth of the output.
Figure 57 shows the ADXL354 application circuit. The analog
outputs (XOUT, YOUT, and ZOUT) are ratiometric to the 1.8 V
analog voltage from the V1P8ANA pin. V1P8ANA can be powered
with an on-chip LDO that is powered from VSUPPLY. V1P8ANA can
also be supplied externally by forcing VSUPPLY to VSS, which
disables the LDO. Due to the ratiometric response, the analog
output requires referencing to the V1P8ANA supply when
digitizing to achieve the inherent noise and offset performance
of the ADXL354. The 0 g bias output is nominally equal to
V1P8ANA/2. The recommended option is to use the ADXL354
with a ratiometric ADC (for example, the Analog Devices, Inc.,
AD7682) with V1P8ANA providing the voltage reference. This
configuration results in self cancellation of errors due to minor
supply variations.
13 YOUT
The micromachined, sensing elements are fully differential,
comprising the lateral x-axis and y-axis sensors and the vertical,
teeter totter z-axis sensors. The x-axis and y-axis sensors and
the z-axis sensors go through separate signal paths that minimize
offset drift and noise. The signal path is fully differential, except
for a differential to single-ended conversion at the analog
outputs of the ADXL354.
ANALOG OUTPUT
14 ZOUT
The ADXL354 is a complete 3-axis, ultralow noise and ultrastable
offset MEMS accelerometer with outputs ratiometric to the analog
1.8 V supply, V1P8ANA. The ADXL355 adds three high resolution
ADCs that use the analog 1.8 V supply as a reference to provide
digital outputs insensitive to the supply voltage. The ADXL354B
is pin selectable for ±2 g or ±4 g full scale, the ADXL354C is pin
selectable for ±2 g or ±8 g full scale, and the ADXL355 is
programmable for ±2.048 g, ±4.096 g, and ±8.192 g full scale.
The ADXL355 offers both SPI and I2C communications ports.
Data Sheet
ADXL354/ADXL355
DIGITAL OUTPUT
AXES OF ACCELERATION SENSITIVITY
Figure 59 shows the ADXL355 application circuit with the
recommended bypass capacitors. The communications interface
is either SPI or I2C (see the Serial Communications section for
additional information).
Figure 58 shows the axes of acceleration sensitivity. Note that
the output voltage increases when accelerated along the
sensitive axis.
Z
The ADXL355 includes an internal configurable digital bandpass filter. Both the high-pass and low-pass poles of the filter
are adjustable, as detailed in the Filter Settings Register section
and Table 43. At power-up, the default conditions for the filters
are as follows:
X
1µF
10 V1P8ANA
ADXL355
0.1µF
TOP VIEW
(Not to Scale)
VSS
8
V1P8DIG
1µF
RESERVED 7
VSSIO 6
VDDIO 5
MISO/ASEL 4
9
1µF
1µF
0.1µF
0.1µF
2.25V TO 3.6V
Figure 59. ADXL355 Application Circuit
Rev. 0 | Page 21 of 42
14205-021
MOSI/SDA 3
0.1µF
11 VSUPPLY
CS/SCL 1
SCLK/VSSIO 2
2.25V TO 3.6V
12 INT1
13 INT2
14 DRDY
Figure 58. Axes of Acceleration Sensitivity
14205-005
High-pass filter (HPF) = dc (off)
Low-pass filter (LPF) = 1000 Hz
Output data rate = 4000 Hz
SPI/I2C
INTERFACE



Y
ADXL354/ADXL355
Data Sheet
POWER SEQUENCING
VDDIO
There are two methods for applying power to the device.
Typically, internal LDO regulators generate the 1.8 V power for
the analog and digital supplies, V1P8ANA and V1P8DIG, respectively.
Optionally, connecting VSUPPLY to VSS and driving V1P8ANA and
V1P8DIG with an external supply can supply V1P8ANA and V1P8DIG.
The VDDIO value determines the logic high levels. On the analog
output ADXL354, VDDIO sets the logic high level for the self test
pins, ST1 and ST2, as well as the STBY pin. On the digital output
ADXL355, VDDIO sets the logic high level for communications
interface ports, as well as the interrupt and DRDY outputs.
When using the internal LDO regulators, connect VSUPPLY to a
voltage source between 2.25 V to 3.6 V. In this case, VDDIO and
VSUPPLY can be powered in parallel. VSUPPLY must not exceed the
VDDIO voltage by greater than 0.5 V. If necessary, VDDIO can be
powered before VSUPPLY.
The LDO regulators are operational when VSUPPLY is between
2.25 V and 3.6 V. V1P8ANA and V1P8DIG are the regulator outputs in
this mode. Alternatively, when tying VSUPPLY to VSS, V1P8ANA and
V1P8DIG are supply voltage inputs with a 1.62 V to 1.98 V range.
When disabling the internal LDO regulators and using an external
1.8 V supply to power V1P8ANA and V1P8DIG, tie VSUPPLY to ground,
and set V1P8ANA and V1P8DIG to the same final voltage level. In the
case of bypassing the LDOs, the recommended power sequence is
to apply power to VDDIO, followed by applying power to V1P8DIG
approximately 10 µs later, and then applying power to V1P8ANA
approximately 10 µs later. If necessary, V1P8DIG and VDDIO can be
powered from the same 1.8 V supply, which can also be tied to
V1P8ANA with proper isolation. In this case, proper decoupling
and low frequency isolation is important to maintain the noise
performance of the sensor.
To avoid electrostatic capture of the proof mass when the
accelerometer is subject to input acceleration beyond its fullscale range, all sensor drive clocks turn off for 0.5 ms. In the
±2 g/±2.048 g range setting, the overrange protection activates
for input signals beyond approximately ±8 g/±8.192 g (±25%),
and for the ±4 g/±4.096 g and ±8 g/±8.192 g range setting, the
threshold corresponds to about ±16 g (±25%).
POWER SUPPLY DESCRIPTION
OVERRANGE PROTECTION
When overrange protection occurs, the XOUT, YOUT, and ZOUT pins
on the ADXL354 begin to drive to midscale. The ADXL355
floats toward zero, and first in, first out (FIFO) begins filling
with this data.
SELF TEST
The ADXL354/ADXL355 have four different power supply
domains: VSUPPLY, V1P8ANA, V1P8DIG, and VDDIO. The internal
analog and digital circuitry operates at 1.8 V nominal.
The ADXL354 and ADXL355 incorporate a self test feature
that effectively tests their mechanical and electronic systems
simultaneously. In ADXL354, drive the ST1 pin to VDDIO to
invoke self test mode. Then, by driving the ST2 pin to VDDIO,
the ADXL354 applies an electrostatic force to the mechanical
sensor and induces a change in output in response to the force.
The self test delta (or response) is the difference in output
voltages between when ST2 is high and ST2 is low, both when
ST1 is asserted. After the self test measurement is complete,
bring both pins low to resume normal operation.
VSUPPLY
VSUPPLY is 2.25 V to 3.6 V, which is the input range to the two
LDO regulators that generate the nominal 1.8 V outputs for
V1P8ANA and V1P8DIG. Connect VSUPPLY to VSS to disable the LDO
regulators, which allows driving V1P8ANA and V1P8DIG from an
external source.
V1P8ANA
All sensor and analog signal processing circuitry operates in
this domain. Offset and sensitivity of the analog output
ADXL354 are ratiometric to this supply voltage. When using
external ADCs, use V1P8ANA as the reference voltage. The digital
output ADXL355 includes ADCs that are ratiometric to V1P8ANA,
thereby rendering offset and sensitivity insensitive to the value
of V1P8ANA. V1P8ANA can be an input or an output as defined by the
state of the VSUPPLY voltage.
The self test operation is similar in the ADXL355, except ST1
and ST2 can be accessed through the SELF_TEST register
(Register 0x2E).
The self test feature rejects externally applied acceleration and
only responds to the self test force, which allows an accurate
measurement of the self test, even in the presence of external
mechanical noise.
V1P8DIG
V1P8DIG is the supply voltage for the internal logic circuitry. A
separate LDO regulator decouples the digital supply noise from
the analog signal path. V1P8ANA can be an input or an output as
defined by the state of the VSUPPLY voltage. If driven externally,
V1P8DIG must be the same voltage as the V1P8ANA voltage.
Rev. 0 | Page 22 of 42
Data Sheet
ADXL354/ADXL355
0
–10
The analog, low-pass antialiasing filter in the ADXL354/
ADXL355 provides a fixed bandwidth of approximately
1.5 kHz, which is where the output response is attenuated by
approximately 50%. The shape of the filter response in the
frequency domain is that of a sinc3 filter.
The ADXL354 x-axis, y-axis, and z-axis analog outputs include
an amplifier followed by a series 32 kΩ resistor and output to
the XOUT, the YOUT, and the ZOUT pins, respectively.
The ADXL355 provides an internal 20-bit, Σ-Δ ADC to digitize
the filtered analog signal. Additional digital filtering (beyond the
analog, low-pass, antialiasing filter) consists of a low-pass digital
decimation filter and a bypassable high-pass filter that supports
output data rates between 4 kHz and 3.9 Hz. The decimation
filter consists of two stages. The first stage is fixed decimation
with a 4 kHz ODR with a low-pass filter cutoff (50% reduction
in output response) at about 1 kHz. A variable second stage
decimation filter is used for the 2 kHz output data rate and below
(it is bypassed for 4 kHz ODR). Figure 60 shows the low-pass
filter response with a 1 kHz corner (4 kHz ODR) for the
–20
–30
–40
–50
–60
–70
1
10
100
INPUT FREQUENCY (Hz)
1k
10k
14205-023
The ADXL354/ADXL355 use an analog, low-pass, antialiasing
filter to reduce out of band noise and to limit bandwidth. The
ADXL355 provides further digital filtering options to maintain
excellent noise performance at various ODRs.
ADXL355. Note that Figure 60 does not include the fixed
frequency analog, low-pass, antialiasing filter with a fixed
bandwidth of approximately 1.5 kHz.
DIGITAL LPF RESPONSE (dB)
FILTER
Figure 60. ADXL355 Digital Low-Pass Filter (LPF) Response for 4 kHz ODR
The ADXL355 pass band of the signal path relates to the
combined filter responses, including the analog filter previously
discussed, and the digital decimation filter/ODR setting. Table 9
shows the delay associated with the decimation filter for each
setting and provides the attenuation at the ODR/4 corner.
Table 9. Digital Filter Group Delay and Profile
Programmed ODR (Hz)
4000
4000/2 = 2000
4000/4 = 1000
4000/8 = 500
4000/16 = 250
4000/32 = 125
4000/64 = 62.5
4000/128 ~ 31
4000/256 ~ 16
4000/512 ~ 8
4000/1024 ~ 4
Delay
ODR (Cycles)
Time (ms)
2.52
0.63
2.00
1.00
1.78
1.78
1.63
3.26
1.57
6.27
1.54
12.34
1.51
24.18
1.49
47.59
1.50
96.25
1.50
189.58
1.50
384.31
Rev. 0 | Page 23 of 42
Attenuation
Decimator at ODR/4 (dB)
Full Path at ODR/4 (dB)
−3.44
−3.63
−2.21
−2.26
−1.92
−1.93
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
−1.83
ADXL354/ADXL355
Data Sheet
The ADXL355 also includes an interpolation filter after the
decimation filters to produce oversampled/upconverted data
that provides an external synchronization option. See the Data
Synchronization section for more details. Table 11 shows the
delay and attenuation relative to the programmed ODR.
Group delay is the digital filter delay from the input to the ADC
until data is available at the interface (see the Filter section).
This delay is the largest component of the total delay from
sensor to serial interface.
40
32.2122
DELAY (ODR CYCLES)
The ADXL355 also includes an optional digital high-pass filter
with a programmable corner frequency. By default, the highpass filter is disabled. The high pass corner frequency, where
the output is attenuated by 50%, is related to the ODR, and the
HPF_CORNER setting in the filter register (Register 0x28,
Bits[6:4]). Table 10 shows the HPF_CORNER response. Figure 61
and Figure 62 show the simulated high-pass filter response and
delay for a 10 Hz cutoff.
30
20
0
9.8801
FREQUENCY (kHz)
14205-025
1
0
–10
Figure 62. High-Pass Filter Delay Response for a 4 kHz ODR and an
HPF_CORNER Setting of 001 (Register 0x28, Bits[6:4])
–20
–30
–40
–50
0
9.8801
100
FREQUENCY (kHz)
14205-024
AMPLITUDE RELATIVE TO FULL SCALE (dB)
10
0
–3
Figure 61. High-Pass Filter Pass-Band Response for a 4 kHz ODR and an
HPF_CORNER Setting of 001 (Register 0x28, Bits[6:4])
Table 10. Digital High-Pass Filter Response
HPF_CORNER Register Setting
(Register 0x28, Bits[6:4])
000
001
010
011
100
101
110
HPF_CORNER Frequency, −3 dB Point Relative to ODR Setting
Not applicable, no high-pass filter enabled
24.7 × 10−4 × ODR
6.2084 × 10−4 × ODR
1.5545 × 10−4 × ODR
0.3862 × 10−4 × ODR
0.0954 × 10−4 × ODR
0.0238 × 10−4 × ODR
−3 dB at 4 kHz ODR (Hz)
Off
9.88
2.48
0.62
0.1545
0.03816
0.00952
Table 11. Combined Digital Interpolation Filter and Decimation Filter Response
Interpolator Data Rate Resolution
Relative to 64 × ODR (Hz)
64 × 4000 = 256000
64 × 2000 = 128000
64 × 1000 = 64000
64 × 500 = 32000
64 × 250 = 16000
64 × 125 = 8000
64 × 62.5 = 4000
64 × 31.25 = 2000
64 × 15.625 = 1000
64 × 7.8125 = 500
64 × 3.90625 = 250
Combined Interpolator/
Decimator Delay (ODR Cycles)
3.51661
3.0126
2.752
2.6346
2.5773
2.5473
2.53257
2.52452
2.52045
2.5194
2.51714
Combined Interpolator/
Decimator Delay (ms)
0.88
1.51
2.75
5.27
10.31
20.38
40.52
80.78
161.31
322.48
644.39
Rev. 0 | Page 24 of 42
Combined Interpolator/Decimator
Output Attenuation at ODR/4 (dB)
−6.18
−4.93
−4.66
−4.58
−4.55
−4.55
−4.55
−4.55
−4.55
−4.55
−4.55
Data Sheet
ADXL354/ADXL355
SERIAL COMMUNICATIONS
ADXL355
SPI PROTOCOL
Wire the ADXL355 for SPI communication as shown in the
connection diagram in Figure 63. The SPI protocol timing is
shown in Figure 64 to Figure 67. The timing scheme follows the
clock polarity (CPOL) = 0 and clock phase (CPHA) = 0. The
SPI clock speed ranges from 100 kHz to 10 MHz.
PROCESSOR
CS
DOUT
MOSI
DOUT
MISO
DIN
SCLK
DOUT
14205-026
The 4-wire serial interface communicates in either the SPI or
I2C protocol. It affectively autodetects the format being used,
requiring no configuration control to select the format.
Figure 63. 4-Wire SPI Connection
CS
1
2
3
4
5
6
7
A6
A5
A4
A3
A2
A1
8
9
10
11
12
13
14
15
16
D7
D6
D5
D4
D3
D2
D1
D0
15
16
SCLK
A0 RW
MISO
14205-027
MOSI
Figure 64. SPI Timing Diagram—Single-Byte Read
CS
1
2
3
4
5
6
7
A6
A5
A4
A3
A2
A1
8
9
10
11
12
13
14
MOSI
A0 RW D7 D6 D5 D4 D3 D2 D1 D0
MISO
14205-028
SCLK
Figure 65. SPI Timing Diagram—Single-Byte Write
CS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
SCLK
A6 A5 A4 A3 A2 A1 A0 RW
BYTE n
BYTE 1
D7 D6 D5 D4 D3 D2 D1 D0 D7
MISO
D0 D7 D6 D5 D4 D3 D2 D1 D0
14205-029
MOSI
Figure 66. SPI Timing Diagram—Multibyte Read
CS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
SCLK
A6 A5 A4 A3 A2
A1 A0 RW D7 D6 D5 D4 D3 D2 D1 D0 D7
D0 D7 D6 D5 D4 D3 D2 D1 D0
MISO
Figure 67. SPI Timing Diagram—Multibyte Write
Rev. 0 | Page 25 of 42
14205-030
BYTE n
BYTE 1
MOSI
ADXL354/ADXL355
Data Sheet
I2C PROTOCOL
recent available. It is not guaranteed that XDATA, YDATA, and
ZDATA form a set corresponding to one sample point in time.
The routine used to retrieve the data from the device controls
this data set continuity. If data transfers are initiated when the
DATA_RDY bit goes high and completes in a time
approximately equal to 1/ODR, XDATA, YDATA, and ZDATA
apply to the same data set.
Figure 68 to Figure 70 detail the I2C protocol timing. The I2C
interface can be used on most buses operating in I2C standard
mode (100 kHz), fast mode (400 kHz), fast mode plus (1 MHz),
and high speed mode (3.4 MHz). The ADXL355 I2C device ID
is as follows:


ASEL (pin) = 0, device address = 0x1D
ASEL (pin) = 1, device address = 0x53
READING ACCELERATION OR TEMPERATURE
DATA FROM THE INTERFACE
For multibyte read or write transactions through either serial
interface, the internal register address autoincrements. When
the top of the register address range, 0x3FF, is reached the autoincrement stops and does not wrap back to Hex Address 0x00.
Acceleration data is left justified and has a register address
order of most significant data to least significant data, which
allows the user to use multibyte transfers and to take only as
much data as required—either 8 bits, 16 bits, or 20 bits plus the
marker. Temperature data is 12 bits unsigned, right justified.
The data in XDATA, YDATA, and ZDATA is always the most
The address autoincrement function disables when the FIFO
address is used, so that data can be read continuously from the
FIFO as a multibyte transaction. In cases where the starting
address of a multibyte transaction is less than the FIFO address,
the address autoincrements until reaching the FIFO address,
and then stops at the FIFO address.
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
SCL
SDA
REGISTER ADDRESS
A5 A4 A3 A2 A1 A0 RW AK
A6
0
REPEAT
START
A6 A5 A4 A3 A2 A1 A0 AK
DEVICE ADDRESS
A6 A5 A4 A3 A2
DATA BYTE
A1 A0 RW AK
0
STOP
D6 D5 D4 D3 D2 D1 D0
SINGLE BYTE READ
AK
INDICATE SDA IS
CONTROLLED BY ADXL355
14205-031
DEVICE ADDRESS
START
2
Figure 68. I C Timing Diagram—Single-Byte Read
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
DEVICE ADDRESS
START
REGISTER ADDRESS
A6 A5 A4 A3 A2 A1 A0 RW AK
SDA
0
DATA BYTE
A6 A5 A4 A3 A2 A1 A0 AK D7 D6 D5 D4 D3 D2 D1 D0 AK
STOP
14205-032
SCL
Figure 69. I2C Timing Diagram—Single-Byte Write
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 19
START
SDA
DEVICE ADDRESS
A6 A5 A4 A3 A2 A1 A0 RW AK
REGISTER ADDRESS
0
DATA BYTE 1
A6 A5 A4 A3 A2 A1 A0 AK D7 D6 D5 D4 D3 D2 D1 D0 AK D7
Figure 70. I2C Timing Diagram—Multibyte Write
Rev. 0 | Page 26 of 42
DATA BYTE n
D0 AK D7 D6 D5 D4 D3 D2 D1 D0 AK
14205-033
SCL
Data Sheet
ADXL354/ADXL355
FIFO
Figure 71 shows the organization of the data in the FIFO. The
acceleration data is twos complement, 20-bit data. The FIFO
control logic inserts the two LSB reads on the interface. Bit 1
indicates that an attempt was made to read an empty FIFO, and
that the data is not valid acceleration data. Bit 0 is a marker bit
to identify the x-axis, which allows a user to verify that the
FIFO data was correctly read. An acceleration data point for a
given axis occupies one FIFO location. The read pointer, RD_PTR,
points to the oldest stored data that was not read already from
the interface (see Figure 71). There are no physical x-acceleration,
y-acceleration, or z-acceleration data registers. This data also comes
directly from the most recent data set in the FIFO, which points
to by the z pointer, Z_PTR, (see Figure 71).
FIFO operates in a stream mode, that is, when the FIFO
overruns new data overwrites the oldest data in the FIFO. A
read from the FIFO address guarantees that the three bytes
associated with the acceleration measurement on an axis all
pertain to the same measurement. The FIFO never overruns,
and data is always taken out in sets (multiples of three data
points).
There are 96 21-bit locations in the FIFO. Each location
contains 20 bits of data and a marker bit for the x-axis data. A
single-byte read from the FIFO address pops one location from
the FIFO. A multibyte read to the FIFO location pops the FIFO
on the read of the first byte and every third byte read thereafter.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
Z_PTR
Z19 Z18 Z17 Z16 Z15 Z14 Z13 Z12
Z11 Z10
Z9
Z8
Z7
Z6
Z5
Z4
Z3
Z2
Z1
Z0
0
0
Z_PTR – 1
Y19 Y18 Y17 Y16 Y15 Y14 Y13 Y12
Y11 Y10 Y9
Y8
Y7
Y6
Y5
Y4
Y3
Y2
Y1
Y0
0
0
Z_PTR – 2
RD_PTR
VIRTUAL BITS
(NOT ALLOCATED IN THE FIFO)
ACCELERATION DATA
EMPTY INDICATOR
X-AXIS MARKER
ASCENDING SPI ADDRESSES
Figure 71. FIFO Data Organization
Rev. 0 | Page 27 of 42
14205-035
DATA SET. SAMPLE POINT
ASCENDING
IS THE SAME ACROSS
A SINGLE X-AXIS, Y-AXIS, SPI ADDRESSES
AND Z-AXIS DATA SET.
ASCENDING FIFO ADDRESSES
Z_PTR + 1
ADXL354/ADXL355
Data Sheet
INTERRUPTS
The status register (Register 0x04) contains five individual bits,
four of which can be mapped to either the INT1 pin, the INT2 pin,
or both. The polarity of the interrupt, active high or active low,
is also selectable via the INT_POL bit in the range (Register 0x2C)
register. In general, the status register clears when read, but this
is not the case if the condition that caused the interrupt persists
after the read of the register. The definition of persist varies
slightly in each case, but it is described in the following sections.
The DRDY pin is similar to an interrupt pins (INTx) but clears
very differently. This case is also described.
FIFO_FULL
The FIFO_FULL bit is set when the entries in the FIFO are
equal to the setting of the FIFO_SAMPLES bits. It clears as
follows:
•
•
If the entries in the FIFO fall below the FIFO_SAMPLES,
which is only the case if sufficient data is read from the
FIFO.
On a read of the status register, but only if the entries in the
FIFO are less than the FIFO_SAMPLES bits.
DATA_RDY
FIFO_OVR
The DATA_RDY bit is set when new acceleration data is
available to the interface. It clears on a read of the status register.
It is not set again until acceleration data that is newer than the
status register read is available.
The FIFO_OVR bit is set when the FIFO is so far overrange that
data is lost. The specified size of the FIFO is 96 locations. There
is an additional three location buffer to compensate for delays
in the synchronization of the clock domains. It is only when
there is an attempt to write past this 99 location limit that
FIFO_OVR is set.
Special logic on the clear of the DATA_RDY bit covers the
corner case where new data arrives during the read of the status
register. In this case, the data ready condition may be missed
completely. This logic results in a delay of the clearing of
DATA_RDY of up to four 512 kHz cycles.
DRDY PIN
DATA is not a status register bit; it instead behaves similar to an
unmaskable interrupt. DRDY is set when new acceleration data
is available to the interface. It clears on a read of the FIFO, on a
read of XDATA, YDATA, or ZDATA, or by an autoclear
function that occurs approximately halfway between output
acceleration data sets.
DRDY is always active high. The INT_POL bit does not affect
DRDY. In EXT_SYNC modes, the first few DRDY pulses after
initial synchronization can be lost or corrupted. The length of
this potential corruption is less than the group delay.
A read of the status register clears FIFO_OVR. It is not set again
until data is lost subsequent to this data register read.
ACTIVITY
The activity bit (Register 0x04, Bit 3) is set when the measured
acceleration on any axis is above the ACT_THRESH bits for
ACT_COUNT consecutive measurements. An over threshold
condition can shift from one axis to another on successive
measurements and is still counted toward the consecutive
ACT_COUNT count.
A read of the status register clears the activity bit (Register 0x04,
Bit 3), but it sets again at the end of the next measurement if the
activity bit (Register 0x04, Bit 3) conditions are still satisfied.
NVM_BUSY
The NVM_BUSY bit indicates that the nonvolatile memory
(NVM) controller is busy, and it cannot be accessed to read,
write, or generate an interrupt.
A status register read that occurs after the NVM controller is no
longer busy clears NVM_BUSY.
Rev. 0 | Page 28 of 42
Data Sheet
ADXL354/ADXL355
EXTERNAL SYNCHRONIZATION AND
INTERPOLATION
There are three possible synchronization options for the ADXL355,
shown in Figure 72 to Figure 74. For clarity, the clock frequencies
and delays are drawn to scale. The labels in Figure 72 to Figure 74
are defined as follows:
•
•
•
Internal ODR is the alignment of the decimated output
data based on the internal clock.
ADC clock shows the internal master clock rate
DRDY is an output indicator signaling a sample is ready.
EXT_SYNC = 01—External Sync and External Clock
The three modes are include as follows:
•
•
•
The advantage of this mode is that data is available at a user
defined sample rate and is asynchronous to the internal oscillator.
The disadvantage of this mode is that the group delay is increased,
and there is increased attenuation at the band edge. Additionally,
because there is a limit to the time resolution, there is some
distortion related to the mismatch of the external sync relative
to the internal oscillator. This mismatch degrades spectral
performance. The group delay is based on the decimation setting
and interpolation setting (see Table 11). Table 13 shows the delay
between the SYNC signal (input) to DRDY (output).
No external synchronization (internal clocks used)
Synchronization with interpolation filter enabled
Sync with an external sync and clock signals, no
interpolation filter
EXT_SYNC = 00—No External Sync or Interpolation
For this case, an internal clock that serves as the synchronization
master generates the data. No external signals are required, and
this is used commonly when the external processor retrieves
data from the device asynchronously and absolute synchronization
to an external source is not required. Use Register 0x28 to program
the ODR.
The device outputs a DRDY (active high) to signal that a new
sample is available, and data is retrieved from the real-time
registers or the FIFO. The group delay is based on the
decimation setting as shown in Table 9.
In this case, an external source provides an external clock at a
frequency of 4 × 64 × ODR. The external clock becomes the
master clock source for the device. In addition, an external
synchronization signal is needed to align the decimation filter
output to a specific clock edge, which provides full external
synchronization and is commonly used when a fixed external
clock captures and processes data, and asynchronous clock(s) are
not allowed. When using multiple sensors, synchronization with an
external master clock is beneficial and requires time alignment.
When configured for EXT_SYNC = 01 with an ODR of 4 kHz,
the user must supply an external clock at 1.024 MHz (64 × 4 ×
4 kHz) on the INT2 pin (Pin 13), and an external synchronization
on DRDY pin (Pin 14), as shown in Table 12.
Special restrictions when using this mode include the following:
•
EXT_SYNC = 10—External Sync with Interpolation
In this case, the internal clock generates data; however, an
interpolation filter provides additional time resolution of 64
times the programmed ODR. Synchronization using interpolation
filters and an external ODR clock is commonly used when the
external processor can provide a synchronization signal (which
is asynchronous to the internal clock) at the desired ODR.
Synchronization with the interpolation filter enabled
(EXT_SYNC = 10) allows the nonsynchronous external clock to
output data most closely associated with the external clock
rising edge. The interpolation filter provides a frequency
resolution related to ODR (see Table 11).
•
•
•
An external clock (EXT_CLK) must be provided as well as
an external sync.
The frequency of EXT_CLK must be exactly 4 × 64 × ODR.
The width of sync must be a minimum of four EXT_CLK
periods.
The phase of sync must meet an approximate 25 ns setup
time to the EXT_CLK rising edge.
When using the EXT_SYNC mode and without providing sync,
the device runs on its own synchronization. Similarly, after
synchronization, the device continues to run synchronized to
the last sync pulse it received, which means that EXT_SYNC = 01
mode can be used with only a single synchronization pulse.
The interpolation filter provides a frequency resolution related to
the ODR (see Table 11). In this case, the data provided corresponds
to the external signal, which can be greater than the set ODR,
but the output pass band remains the same it was prior to the
interpolation filter.
Table 12. Multiplexing of INT2 and DRDY
EXT_CLK
0
0
1
1
0
0
Register or Bit Fields
EXT_SYNC[1:0] INT_MAP[7:4]
00
0000
00
Not 0000
00
0000
00
Not 00002
01
0000
011
Not 0000
INT2 (Pin 13)
Low
INT2
EXT_CLK
EXT_CLK
DRDY
INT2
Pins
DRDY (Pin 14)
DRDY
DRDY
DRDY
DRDY
SYNC
SYNC
Rev. 0 | Page 29 of 42
Comments
Synchronization is to the internal clocks, and there is
no external clock synchronization.
These options reset the digital filters on every
synchronization pulse and are not recommended.
ADXL354/ADXL355
Data Sheet
EXT_CLK
1
1
Register or Bit Fields
EXT_SYNC[1:0] INT_MAP[7:4]
011
0000
011
Not 00002
INT2 (Pin 13)
EXT_CLK
EXT_CLK
0
0
1
1
10
101
101
101
DRDY
INT2
EXT_CLK
EXT_CLK
1
2
0000
Not 0000
0000
Not 0000
Pins
DRDY (Pin 14)
SYNC
SYNC
SYNC
SYNC
SYNC
SYNC
Comments
External synchronization, no interpolation filter, and
DRDY (active high) signals that data is ready. Data
represents a sample point group delay earlier in time.
External synchronization, interpolation filter, and
DRDY (active high) signals that data is ready. Data
sample group delay earlier in time.
No DRDY.
No INT2, even though it is enabled.
GROUP DELAY
(FIXED RELATIVE TO DRDY)
SAMPLE POINT
INTERNAL ODR
14205-036
ADC MOD. CLK.
64× ODR
DRDY
Figure 72. External Synchronization Option—EXT_SYNC = 00, Internal Sync
SAMPLE POINT
GROUP DELAY
(FIXED RELATIVE TO SYNC)
INTERFACE SYNCHRONIZATION DELAY
INTERNAL ODR
14205-037
INTERPOLATOR
64× ODR
SYNC
110% ODR
DRDY
Figure 73. External Synchronization Option—EXT_SYNC = 10, External Sync, External Clock, Interpolation Filter
SAMPLE POINT
GROUP DELAY
(FIXED RELATIVE TO SYNC)
INTERNAL ODR
EXT_CLK
(4 × 64) × SYNC
SYNCHRONIZE
14205-038
SYNC
LOST SAMPLE
DRDY
Figure 74. External Synchronization Option—EXT_SYNC = 01, External Sync, No Interpolation Filter
Table 13. EXT_SYNC = 10, DRDY Delay
ODR_LPF
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
0x8
0x9
0x10
Delay (OSC Cycles)
8
10
14
22
38
70
134
262
1031
2054
4102
Rev. 0 | Page 30 of 42
Data Sheet
ADXL354/ADXL355
ADXL355 REGISTER MAP
Note that while configuring the ADXL355 in an application, all configuration registers must be programmed before enabling measurement mode
in the POWER_CTL register. When the ADXL355 is in measurement mode, only the following configurations can change: the HPF_CORNER
bits in the filter register, the INT_MAP register, the ST1 and ST2 bits in the SELF_TEST register, and the reset register.
Table 14. ADXL355 Register Map
Hex. Addr. Register Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset R/W
0x00
DEVID_AD
DEVID_AD
0xAD R
0x01
DEVID_MST
DEVID_MST
0x1D R
0x02
PARTID
PARTID
0xED R
0x03
REVID
REVID
0x01
R
0x04
Status
FIFO_FULL DATA_RDY 0x00
R
0x05
FIFO_ENTRIES
0x00
R
0x06
TEMP2
0x00
R
0x07
TEMP1
Temperature, Bits[7:0]
0x00
R
0x08
XDATA3
XDATA, Bits[19:12]
0x00
R
0x09
XDATA2
XDATA, Bits[11:4]
0x00
R
0x0A
XDATA1
0x00
R
0x0B
YDATA3
YDATA, Bits[19:12]
0x00
R
0x0C
YDATA2
YDATA, Bits[11:4]
0x00
R
0x0D
YDATA1
0x00
R
0x0E
ZDATA3
ZDATA, Bits[19:12]
0x00
R
0x0F
ZDATA2
ZDATA, Bits[11:4]
0x00
R
0x10
ZDATA1
0x00
R
0x11
FIFO_DATA
FIFO_DATA
0x00
R
0x1E
OFFSET_X_H
OFFSET_X, Bits[15:8]
0x00
R/W
0x1F
OFFSET_X_L
OFFSET_X, Bits[7:0]
0x00
R/W
0x20
OFFSET_Y_H
OFFSET_Y, Bits[15:8]
0x00
R/W
0x21
OFFSET_Y_L
OFFSET_Y, Bits[7:0]
0x00
R/W
0x22
OFFSET_Z_H
OFFSET_Z, Bits[15:8]
0x00
R/W
0x23
OFFSET_Z_L
OFFSET_Z, Bits[7:0]
0x00
R/W
0x24
ACT_EN
0x00
R/W
0x25
ACT_THRESH_H
ACT_THRESH, Bits[15:8]
0x00
R/W
0x26
ACT_THRESH_L
ACT_THRESH, Bits[7:0]
0x00
R/W
0x27
ACT_COUNT
ACT_COUNT
0x01
R/W
0x28
Filter
Reserved
0x00
R/W
0x29
FIFO_SAMPLES
Reserved
0x60
R/W
0x2A
INT_MAP
ACT_EN2 OVR_EN2 FULL_EN2 RDY_EN2
0x00
R/W
0x2B
Sync
EXT_SYNC
0x00
R/W
0x2C
Range
Range
0x81
R/W
0x2D
POWER_CTL
0x01
R/W
0x2E
SELF_TEST
0x00
R/W
0x2F
Reset
0x00
W
Reserved
NVM_BUSY Activity
Reserved
FIFO_OVR
FIFO_ENTRIES
Reserved
Temperature, Bits[11:8]
XDATA, Bits[3:0]
Reserved
YDATA, Bits[3:0]
Reserved
ZDATA, Bits[3:0]
Reserved
Reserved
ACT_Z
HPF_CORNER
ACT_X
ODR_LPF
FIFO_SAMPLES
ACT_EN1 OVR_EN1
Reserved
I2C_HS
ACT_Y
INT_POL
FULL_EN1
EXT_CLK
Reserved
Reserved
RDY_EN1
DRDY_OFF TEMP_OFF STANDBY
Reserved
ST2
Reset
Rev. 0 | Page 31 of 42
ST1
ADXL354/ADXL355
Data Sheet
REGISTER DEFINITIONS
This section describes the functions of the ADXL355 registers. The ADXL355 powers up with the default register values, as shown in the
Reset column of Table 14.
ANALOG DEVICES ID REGISTER
This register contains the Analog Devices ID, 0xAD.
Address: 0x00, Reset: 0xAD, Name: DEVID_AD
Table 15. Bit Descriptions for DEVID_AD
Bits
[7:0]
Bit Name
DEVID_AD
Settings
Description
Analog Devices ID
Reset
0xAD
Access
R
ANALOG DEVICES MEMS ID REGISTER
This register contains the Analog Devices MEMS ID, 0x1D.
Address: 0x01, Reset: 0x1D, Name: DEVID_MST
Table 16. Bit Descriptions for DEVID_MST
Bits
[7:0]
Bit Name
DEVID_MST
Settings
Description
Analog Devices MEMS ID
Reset
0x1D
Access
R
DEVICE ID REGISTER
This register contains the device ID, 0xED (355 octal).
Address: 0x02, Reset: 0xED, Name: PARTID
Table 17. Bit Descriptions for PARTID
Bits
[7:0]
Bit Name
PARTID
Settings
Description
Device ID (355 octal)
Reset
0xED
Access
R
PRODUCT REVISION ID REGISTER
This register contains the product revision ID, beginning with 0x00 and incrementing for each subsequent revision.
Address: 0x03, Reset: 0x00, Name: REVID
Table 18. Bit Descriptions for REVID
Bits
[7:0]
Bit Name
REVID
Settings
Description
Mask revision
Reset
0x01
Access
R
STATUS REGISTER
This register includes bits that describe the various conditions of the ADXL355.
Address: 0x04, Reset: 0x00, Name: STATUS
Table 19. Bit Descriptions for STATUS
Bits
[7:5]
4
3
2
1
0
Bit Name
Reserved
NVM_BUSY
Activity
FIFO_OVR
FIFO_FULL
DATA_RDY
Settings
Description
Reserved.
NVM controller is busy with either refresh, programming, or built-in, self test (BIST).
Activity, as defined in the THRESH_ACT and COUNT_ACT registers, is detected.
FIFO has overrun, and the oldest data is lost.
FIFO watermark is reached.
A complete x-axis, y-axis, and z-axis measurement was made and results can be read.
Rev. 0 | Page 32 of 42
Reset
0x0
0x0
0x0
0x0
0x0
0x0
Access
R
R
R
R
R
R
Data Sheet
ADXL354/ADXL355
FIFO ENTRIES REGISTER
This register indicates the number of valid data samples present in the FIFO buffer. This number ranges from 0 to 96.
Address: 0x05, Reset: 0x00, Name: FIFO_ENTRIES
Table 20. Bit Descriptions for FIFO_ENTRIES
Bits
7
Bit Name
Reserved
[6:0]
FIFO_ENTRIES
Settings
Description
Reserved
Reset
0x0
Access
R
Number of data samples stored in the FIFO
0x0
R
TEMPERATURE DATA REGISTERS
These two registers contain the uncalibrated temperature data. The nominal intercept is 1852 LSB at 25°C and the nominal slope is
−9.05 LSB/°C. TEMP2 contains the four most significant bits, and TEMP1 contains the eight least significant bits of the 12-bit value.
Address: 0x06, Reset: 0x00, Name: TEMP2
Table 21. Bit Descriptions for TEMP2
Bits
[7:4]
[3:0]
Bit Name
Reserved
Temperature, Bits[11:8]
Settings
Description
Reserved.
Uncalibrated temperature data
Reset
Access
0x0
R
Reset
0x0
Access
R
Address: 0x07, Reset: 0x00, Name: TEMP1
Table 22. Bit Descriptions for TEMP1
Bits
[7:0]
Bit Name
Temperature, Bits[7:0]
Settings
Description
Uncalibrated temperature data
X-AXIS DATA REGISTERS
These three registers contain the x-axis acceleration data. Data is left justified and formatted as twos complement.
Address: 0x08, Reset: 0x00, Name: XDATA3
Table 23. Bit Descriptions for XDATA3
Bits
[7:0]
Bit Name
XDATA, Bits[19:12]
Settings
Description
X-axis data
Reset
0x0
Access
R
Address: 0x09, Reset: 0x00, Name: XDATA2
Table 24. Bit Descriptions for XDATA2
Bits
[7:0]
Bit Name
XDATA, Bits[11:4]
Settings
Description
X-axis data
Reset
0x0
Access
R
Reset
0x0
0x0
Access
R
R
Address: 0x0A, Reset: 0x00, Name: XDATA1
Table 25. Bit Descriptions for XDATA1
Bits
[7:4]
[3:0]
Bit Name
XDATA, Bits[3:0]
Reserved
Settings
Description
X-axis data
Reserved
Rev. 0 | Page 33 of 42
ADXL354/ADXL355
Data Sheet
Y-AXIS DATA REGISTERS
These three registers contain the y-axis acceleration data. Data is left justified and formatted as twos complement.
Address: 0x0B, Reset: 0x00, Name: YDATA3
Table 26. Bit Descriptions for YDATA3
Bits
[7:0]
Bit Name
YDATA, Bits[19:12]
Settings
Description
Y-axis data
Reset
0x0
Access
R
Reset
0x0
Access
R
Reset
0x0
0x0
Access
R
R
Address: 0x0C, Reset: 0x00, Name: YDATA2
Table 27. Bit Descriptions for YDATA2
Bits
[7:0]
Bit Name
YDATA, Bits[11:4]
Settings
Description
Y-axis data
Address: 0x0D, Reset: 0x00, Name: YDATA1
Table 28. Bit Descriptions for YDATA1
Bits
[7:4]
[3:0]
Bit Name
YDATA, Bits[3:0]
Reserved
Settings
Description
Y-axis data
Reserved
Z-AXIS DATA REGISTERS
These three registers contain the z-axis acceleration data. Data is left justified and formatted as twos complement.
Address: 0x0E, Reset: 0x00, Name: ZDATA3
Table 29. Bit Descriptions for ZDATA3
Bits
[7:0]
Bit Name
ZDATA, Bits[19:12]
Settings
Description
Z-axis data
Reset
0x0
Access
R
Reset
0x0
Access
R
Address: 0x0F, Reset: 0x00, Name: ZDATA2
Table 30. Bit Descriptions for ZDATA2
Bits
[7:0]
Bit Name
ZDATA, Bits[11:4]
Settings
Description
Z-axis data
Address: 0x10, Reset: 0x00, Name: ZDATA1
Table 31. Bit Descriptions for ZDATA1
Bits
[7:4]
[3:0]
Bit Name
ZDATA, Bits[3:0]
Reserved
Settings
Description
Z-axis data
Reserved
Rev. 0 | Page 34 of 42
Reset
0x0
0x0
Access
R
R
Data Sheet
ADXL354/ADXL355
FIFO ACCESS REGISTER
Address: 0x11, Reset: 0x00, Name: FIFO_DATA
Read this register to access data stored in the FIFO.
Table 32. Bit Descriptions for FIFO_DATA
Bits
[7:0]
Bit Name
FIFO_DATA
Settings
Description
FIFO data is formatted to 24 bits, 3 bytes, most significant byte first. A read to this
address pops an effective three equal byte words of axis data from the FIFO. Two
subsequent reads or a multibyte read completes the transaction of this data onto the
interface. Continued reading or a sustained multibyte read of this field continues to
pop the FIFO every third byte. Multibyte reads to this address do not increment the
address pointer. If this address is read due to an autoincrement from the previous
address, it does not pop the FIFO. Instead, it returns zeros and increments on to the
next address.
Reset
0x0
Access
R
Reset
0x0
Access
R/W
Reset
0x0
Access
R/W
Reset
0x0
Access
R/W
Reset
0x0
Access
R/W
X-AXIS OFFSET TRIM REGISTERS
Address: 0x1E, Reset: 0x00, Name: OFFSET_X_H
Table 33. Bit Descriptions for OFFSET_X_H
Bits
[7:0]
Bit Name
OFFSET_X,
Bits[15:8]
Settings
Description
Offset added to x-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_X[15:0] matches the significance of XDATA[19:4].
Address: 0x1F, Reset: 0x00, Name: OFFSET_X_L
Table 34. Bit Descriptions for OFFSET_X_L
Bits
[7:0]
Bit Name
OFFSET_X,
Bits[7:0]
Settings
Description
Offset added to x-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_X[15:0] matches the significance of XDATA[19:4].
Y-AXIS OFFSET TRIM REGISTERS
Address: 0x20, Reset: 0x00, Name: OFFSET_Y_H
Table 35. Bit Descriptions for OFFSET_Y_H
Bits
[7:0]
Bit Name
OFFSET_Y,
Bits[15:8]
Settings
Description
Offset added to y-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_Y[15:0] matches the significance of YDATA[19:4].
Address: 0x21, Reset: 0x00, Name: OFFSET_Y_L
Table 36. Bit Descriptions for OFFSET_Y_L
Bits
[7:0]
Bit Name
OFFSET_Y,
Bits[7:0]
Settings
Description
Offset added to y-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_Y[15:0] matches the significance of YDATA[19:4].
Rev. 0 | Page 35 of 42
ADXL354/ADXL355
Data Sheet
Z-AXIS OFFSET TRIM REGISTERS
Address: 0x22, Reset: 0x00, Name: OFFSET_Z_H
Table 37. Bit Descriptions for OFFSET_Z_H
Bits
[7:0]
Bit Name
OFFSET_Z,
Bits[15:8]
Settings
Description
Offset added to z-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_Z[15:0] matches the significance of ZDATA[19:4].
Reset
0x0
Access
R/W
Reset
0x0
Access
R/W
Address: 0x23, Reset: 0x00, Name: OFFSET_Z_L
Table 38. Bit Descriptions for OFFSET_Z_L
Bits
[7:0]
Bit Name
OFFSET_Z,
Bits[7:0]
Settings
Description
Offset added to z-axis data after all other signal processing. Data is in twos complement
format. The significance of OFFSET_Z[15:0] matches the significance of ZDATA[19:4].
ACTIVITY ENABLE REGISTER
Address: 0x24, Reset: 0x00, Name: ACT_EN
Table 39. Bit Descriptions for ACT_EN
Bits
[7:3]
2
1
0
Bit Name
Reserved
ACT_Z
ACT_Y
ACT_X
Settings
Description
Reserved.
Z-axis data is a component of the activity detection algorithm.
Y-axis data is a component of the activity detection algorithm.
X-axis data is a component of the activity detection algorithm.
Reset
0x0
0x0
0x0
0x0
Access
R
R/W
R/W
R/W
ACTIVITY THRESHOLD REGISTERS
Address: 0x25, Reset: 0x00, Name: ACT_THRESH_H
Table 40. Bit Descriptions for ACT_THRESH_H
Bits
[7:0]
Bit Name
ACT_THRESH[15:8]
Settings
Description
Threshold for activity detection. Acceleration magnitude must be above
ACT_THRESH to trigger the activity counter. ACT_THRESH is an unsigned
magnitude. The significance of ACT_TRESH[15:0] matches the significance of
XDATA, YDATA, and ZDATA[18:3].
Reset
0x0
Access
R/W
Reset
0x0
Access
R/W
Address: 0x26, Reset: 0x00, Name: ACT_THRESH_L
Table 41. Bit Descriptions for THRESH_ACT_X_L
Bits
[7:0]
Bit Name
ACT_THRESH[7:0]
Settings
Description
Threshold for activity detection. Acceleration magnitude must be above
ACT_THRESH to trigger the activity counter. ACT_THRESH is an unsigned
magnitude. The significance of ACT_TRESH[15:0] matches the significance of
XDATA, YDATA, and ZDATA[18:3].
ACTIVITY COUNT REGISTER
Address: 0x27, Reset: 0x01, Name: ACT_COUNT
Table 42. Bit Descriptions for ACT_COUNT
Bits
[7:0]
Bit Name
ACT_COUNT
Settings
Description
Number of consecutive events above threshold required to detect activity
Rev. 0 | Page 36 of 42
Reset
0x1
Access
R/W
Data Sheet
ADXL354/ADXL355
FILTER SETTINGS REGISTER
Address: 0x28, Reset: 0x00, Name: Filter
Use this register to specify parameters for the internal high-pass and low-pass filters.
Table 43. Bit Descriptions for Filter
Bits
7
[6:4]
Bit Name
Reserved
HPF_CORNER
Settings
000
001
010
011
100
101
110
[3:0]
ODR_LPF
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
Description
Reserved
−3 dB filter corner for the first-order, high-pass filter relative to the ODR
Not applicable, no high-pass filter enabled
247 × 10−3 × ODR
62.084 × 10−3 × ODR
15.545 × 10−3 × ODR
3.862 × 10−3 × ODR
0.954 × 10−3 × ODR
0.238 × 10−3 × ODR
ODR and low-pass filter corner
4000 Hz and 1000 Hz
2000 Hz and 500 Hz
1000 Hz and 250 Hz
500 Hz and 125 Hz
250 Hz and 62.5 Hz
125 Hz and 31.25 Hz
62.5 Hz and 15.625 Hz
31.25 Hz and 7.813 Hz
15.625 Hz and 3.906 Hz
7.813 Hz and 1.953 Hz
3.906 Hz and 0.977 Hz
Reset
0x0
0x0
Access
R
R/W
0x0
R/W
FIFO SAMPLES REGISTER
Address: 0x29, Reset: 0x60, Name: FIFO_SAMPLES
Use the FIFO_SAMPLES value to specify the number of samples to store in the FIFO. The default value of this register is 0x60 to avoid
triggering the FIFO watermark interrupt.
Table 44. Bit Descriptions for FIFO_SAMPLES
Bits
7
[6:0]
Bit Name
Reserved
FIFO_SAMPLES
Settings
Description
Reserved.
Watermark number of samples stored in the FIFO that triggers a FIFO_FULL condition.
Values range from 1 to 96.
Reset
0x0
0x60
Access
R
R/W
INTERRUPT PIN (INTx) FUNCTION MAP REGISTER
Address: 0x2A, Reset: 0x00, Name: INT_MAP
The INT_MAP register configures the interrupt pins. Bits[7:0] select which function(s) generate an interrupt on the INT1 and INT2 pins.
Multiple events can be configured. If the corresponding bit is set to 1, the function generates an interrupt on the interrupt pins.
Table 45. Bit Descriptions for INT_MAP
Bits
7
6
5
4
3
2
1
0
Bit Name
ACT_EN2
OVR_EN2
FULL_EN2
RDY_EN2
ACT_EN1
OVR_EN1
FULL_EN1
RDY_EN1
Settings
Description
Activity interrupt enable on INT2
FIFO_OVR interrupt enable on INT2
FIFO_FULL interrupt enable on INT2
DATA_RDY interrupt enable on INT2
Activity interrupt enable on INT1
FIFO_OVR interrupt enable on INT1
FIFO_FULL interrupt enable on INT1
DATA_RDY interrupt enable on INT1
Rev. 0 | Page 37 of 42
Reset
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
ADXL354/ADXL355
Data Sheet
DATA SYNCHRONIZATION
Address: 0x2B, Reset: 0x00, Name: Sync
Use this register to control the external timing triggers.
Table 46. Bit Descriptions for Sync
Bits
[7:3]
2
[1:0]
Bit Name
Reserved
EXT_CLK
EXT_SYNC
Settings
00
01
10
11
Description
Reserved.
Enable external clock.
Enable external sync control.
Internal sync.
External sync, no interpolation filter. After synchronization, and for EXT_SYNC within
specification, DATA_RDY occurs on EXT_SYNC.
External sync, interpolation filter, next available data indicated by DATA_RDY 14 to
8204 oscillator cycles later (longer delay for higher ODR_LPF setting), data represents
a sample point group delay earlier in time.
Reserved.
Reset
0x0
0x0
0x0
Access
R
R/W
R/W
I2C SPEED, INTERRUPT POLARITY, AND RANGE REGISTER
Address: 0x2C, Reset: 0x81, Name: Range
Table 47. Bit Descriptions for Range
Bits
7
Bit Name
I2C_HS
6
INT_POL
Settings
0
1
[5:2]
[1:0]
Reserved
Range
01
10
11
Description
I2C speed.
1 = high speed mode.
0 = fast mode.
Interrupt polarity.
INT1 and INT2 are active low.
INT1 and INT2 are active high.
Reserved.
Range.
±2 g.
±4 g.
±8 g.
Reset
0x1
Access
R/W
0x0
R/W
0x0
0x1
R
R/W
POWER CONTROL REGISTER
Address: 0x2D, Reset: 0x01, Name: POWER_CTL
Table 48. Bit Descriptions for POWER_CTL
Bits
[7:3]
2
1
Bit Name
Reserved
DRDY_OFF
TEMP_OFF
0
STANDBY
Settings
1
0
Description
Reserved.
Set to 1 to force the DRDY output to 0 in modes where it is normally signal data ready.
Set to 1 to disable temperature processing. Temperature processing is also disabled
when STANDBY = 1.
Standby or measurement mode.
Standby mode. In standby mode, the device is in a low power state, and the
temperature and acceleration datapaths are not operating. In addition, digital
functions, including FIFO pointers, reset. Changes to the configuration setting of the
device must be made when STANDBY = 1. An exception is a high-pass filter that can
be changed when the device is operating.
Measurement mode.
Rev. 0 | Page 38 of 42
Reset
0x0
0x0
0x0
Access
R
R/W
R/W
0x1
R/W
Data Sheet
ADXL354/ADXL355
SELF TEST REGISTER
Address: 0x2E, Reset: 0x00, Name: SELF_TEST
Refer to the Self Test section for more information on the operation of the self test feature.
Table 49. Bit Descriptions for SELF_TEST
Bits
[7:2]
1
0
Bit Name
Reserved
ST2
ST1
Settings
Description
Reserved.
Set to 1 to enable self test force
Set to 1 to enable self test mode
Reset
0x0
0x0
0x0
Access
R
R/W
R/W
RESET REGISTER
Address: 0x2F, Reset: 0x00, Name: Reset
Table 50. Bit Descriptions for Reset
Bits
[7:0]
Bit Name
Reset
Settings
Description
Write Code 0x52 to resets the device, similar to a power-on reset (POR)
Rev. 0 | Page 39 of 42
Reset
0x0
Access
W
ADXL354/ADXL355
Data Sheet
RECOMMENDED SOLDERING PROFILE
Figure 75 and Table 51 provide details about the recommended soldering profile.
CRITICAL ZONE
TL TO TP
tP
TP
tL
TSMAX
TSMIN
tS
RAMP-DOWN
PREHEAT
t25°C TO PEAK
TIME
14205-039
TEMPERATURE
RAMP-UP
TL
Figure 75. Recommended Soldering Profile
Table 51. Recommended Soldering Profile
Profile Feature
Average Ramp Rate from Liquid Temperature (TL) to Peak Temperature (TP)
Preheat
Minimum Temperature (TSMIN)
Maximum Temperature (TSMAX)
Time from TSMIN to TSMAX (tS)
TSMAX to TL Ramp-Up Rate
Liquid Temperature (TL)
Time Maintained Above TL (tL)
Peak Temperature (TP)
Time of Actual TP − 5°C (tP)
Ramp-Down Rate
Time from 25°C to Peak Temperature (t25°C TO PEAK)
Rev. 0 | Page 40 of 42
Sn63/Pb37
3°C/sec maximum
Condition
Pb-Free
3°C/sec maximum
100°C
150°C
60 sec to 120 sec
3°C/sec maximum
183°C
60 sec to 150 sec
240°C + 0°C/−5°C
10 sec to 30 sec
6°C/sec maximum
6 minutes maximum
150°C
200°C
60 sec to 180 sec
3°C/sec maximum
217°C
60 sec to 150 sec
260°C + 0°C/−5°C
20 sec to 40 sec
6°C/sec maximum
8 minutes maximum
Data Sheet
ADXL354/ADXL355
PCB FOOTPRINT PATTERN
Figure 76 shows the PCB footprint pattern and dimensions in millimeters.
3.22mm
0.68mm
0.70mm
3.80mm
14 PLCS
1.8mm × 0.68mm
3.80mm
Figure 76. PCB Footprint Pattern and Dimensions in Millimeters
Rev. 0 | Page 41 of 42
14205-040
4.5mm
0.70mm
ADXL354/ADXL355
Data Sheet
PACKAGING AND ORDERING INFORMATION
OUTLINE DIMENSIONS
DETAIL A
6.25
6.00 SQ
5.85
0.80
BSC
2.25
2.05
1.85
1.674 BSC
0.510 REF
0.30 SQ
12
(PIN 1 INDEX)
14
11
1
DETAIL A
5.60
SQ
R 0.103
(14 PLCS)
3.81
REF
0.508
BSC
4
8
7
TOP VIEW
0.10 BSC
R 0.203
(14 PLCS)
0.15
BSC
5
BOTTOM VIEW
SIDE VIEW
2.20 REF
2.54 REF
0.914
BSC
05-27-2016-B
PKG-004554
R 0.25
(4 PLCS)
Figure 77. 14-Terminal Ceramic Leadless Chip Carrier [LCC]
(E-14-1)
Dimensions shown in millimeters
BRANDING INFORMATION
NO BRAND ON THIS LINE
PART NUMBER
PIN ONE LOCATOR, NO OTHER BRAND ON THIS LINE
ADXL354B, ADXL354C, OR ADXL355B
SIX DIGIT LOT NUMBER
6 DIGIT LOT NUMBER
14205-078
TWO DIGIT YEAR, TWO DIGIT WEEK ID
#YYWW
Figure 78. Branding Information
ORDERING GUIDE
Model1
ADXL354BEZ
ADXL354BEZ-RL
ADXL354BEZ-RL7
ADXL354CEZ
ADXL354CEZ-RL
ADXL354CEZ-RL7
ADXL355BEZ
Output
Mode
Analog
Analog
Analog
Analog
Analog
Analog
Digital
ADXL355BEZ-RL
Digital
ADXL355BEZ-RL7
Digital
Measurement
Range (g)
±2, ±4
±2, ±4
±2, ±4
±2, ±8
±2, ±8
±2, ±8
±2.048, ±4.096,
±8.192
±2.048, ±4.096,
±8.192
±2.048, ±4.096,
±8.192
Specified
Voltage (V)
3.3
3.3
3.3
3.3
3.3
3.3
3.3
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
14-Terminal LCC
14-Terminal LCC
14-Terminal LCC
14-Terminal LCC
14-Terminal LCC
14-Terminal LCC
14-Terminal LCC
Package
Option
E-14-1
E-14-1
E-14-1
E-14-1
E-14-1
E-14-1
E-14-1
3.3
−40°C to +125°C
14-Terminal LCC
E-14-1
3.3
−40°C to +125°C
14-Terminal LCC
E-14-1
EVAL-ADXL354BZ
EVAL-ADXL354CZ
EVAL-ADXL355Z
1
Evaluation Board for ADXL354BEZ
Evaluation Board for ADXL354CEZ
Evaluation Board for ADXL355BEZ
Z = RoHS-Compliant Part.
©2016 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D14205-0-9/16(0)
Rev. 0 | Page 42 of 42
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