AD ADIS16240 Low power, programmable impact sensor and recorder Datasheet

Low Power, Programmable
Impact Sensor and Recorder
ADIS16240
FEATURES
FUNCTIONAL BLOCK DIAGRAM
AN
ADIS16240
XA
YA
TRIPLE-AXIS
MEMS
ACCELEROMETER
ZA
ANALOGTO-DIGITAL
CONVERSION
AND
PROCESSING
VDD
POWER
MANAGEMENT
DIGITAL
CONTROL
AND
SPI
INTERFACE
TEMPERATURE
SENSOR
CMP1
CMP2
ALARM
DETECTION
EVENT TRIGGER
EVENT
CAPTURE
BUFFER
CS
SCLK
DIN
DOUT
RST
DIO1
DIO2
08133-001
Digital triple-axis accelerometer, ±19 g
Programmable event recorder
Internal and external trigger inputs
Low power operation
Sleep mode current: 100 μA
Continuous sampling current: 1 mA, 1 kSPS
Wake-up and record function
External trigger input and SPI trigger command
Peak acceleration sample-and-hold
Peak XYZ sum-of-squares output
1600 Hz (X, Y) and 550 Hz (Z) sensor bandwidth
Digitally controlled bias correction
Digitally controlled sample rate, up to 4096 SPS
Programmable alarms for condition monitoring
Programmable digital input/output lines
Data-ready output and alarm indicator output
Real-time clock
Digitally activated self-test
Embedded temperature sensor
Programmable power management
SPI-compatible serial interface
Auxiliary 10-bit ADC input
Two analog trigger inputs with programmable threshold
Single-supply operation: 2.4 V to 3.6 V
>4000 g powered shock survivability
Figure 1.
APPLICATIONS
Crash or impact detection
Condition monitoring of valuable goods
Safety, shut-off sensing
Impact event recording
Security sensing and tamper detection
GENERAL DESCRIPTION
The ADIS16240 is a fully integrated digital shock detection and
recorder system. It combines industry-leading iMEMS® technology
with a signal processing solution that optimizes dynamic performance for low power applications. The triple-axis sensing element
enables shock measurement in all directions, eliminating the need
for additional sensors and complex mechanical structures for
many applications. The digital serial peripheral interface (SPI)
uses four wires and is compatible with most processor platforms.
The SPI interface provides access to sensor data and a set of configuration registers that control such operational parameters as
offset bias correction, sample rate, sleep mode, peak detection,
and event capture.
The programmable event recorder offers two trigger modes. The
internal mode monitors continuous sampled data and triggers the
capture, based on the user-defined threshold. The external mode
uses the two comparator inputs and a user-defined threshold to
trigger the event captures. This function also provides user configuration controls for capture length, pretrigger data, and data storage.
Each event is stored with a header that captures temperature, power
supply, and time. Several power management features, including
sleep mode and a wake-up function, enable power optimization
with respect to specific mechanical system requirements.
The ADIS16240 is available in a 12 mm × 12 mm laminate-based
ball grid array (BGA) that meets IPC/JEDEC standards for Pb-free
solder reflow processing (J-STD-020C and J-STD-033).
Rev. 0
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
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2009 Analog Devices, Inc. All rights reserved.
ADIS16240
TABLE OF CONTENTS
Features .............................................................................................. 1
Sensing Element ............................................................................8
Applications ....................................................................................... 1
Data Sampling and Processing ....................................................8
Functional Block Diagram .............................................................. 1
User Interface .................................................................................8
General Description ......................................................................... 1
Capture ...........................................................................................8
Revision History ............................................................................... 2
Basic Operation .................................................................................9
Specifications..................................................................................... 3
Memory Map .............................................................................. 10
Timing Specifications .................................................................. 4
Output Data Registers ............................................................... 11
Absolute Maximum Ratings............................................................ 5
Event Recorder ........................................................................... 12
ESD Caution .................................................................................. 5
Operational Control................................................................... 14
Pin Configuration and Function Descriptions ............................. 6
Outline Dimensions ....................................................................... 16
Typical Performance Characteristics ............................................. 7
Ordering Guide .......................................................................... 16
Theory of Operation ........................................................................ 8
REVISION HISTORY
4/09—Revision 0: Initial Version
Rev. 0 | Page 2 of 16
ADIS16240
SPECIFICATIONS
TA = 25°C, VDD = 2.4 V to 3.6 V unless otherwise noted.
Table 1.
Parameter
ACCELEROMETER
Dynamic Range
Initial Sensitivity
Sensitivity Temperature Coefficient
Sensitivity Change with Supply Voltage
Nonlinearity
Sensor-to-Sensor Alignment Error
Cross-Axis Sensitivity
Initial Bias Error
Bias Temperature Coefficient
Bias Voltage Sensitivity
Output Noise
Noise Density
Bandwidth
Conditions
Axis
−40°C to +85°C
2.4 V < VDD < 3.6 V
Compare with best fit line
Typ
±16
±19
51.4
±0.01
6
±2
±0.1
±1
X, Y
−2.7
No external capacitance
No external capacitance
Sensor Resonant Frequency
Self-Test Change in Output Response
TEMPERATURE SENSOR SCALE FACTOR
ADC INPUT
Input Range
Resolution
Integral Nonlinearity, INL
Differential Nonlinearity, DNL
Offset Error
Gain Error
Input Capacitance
LOGIC INPUTS 1
Input High Voltage, VINH
Input Low Voltage, VINL
Logic 1 Input Current, IINH
Logic 0 Input Current, IINL
Input Capacitance, CIN
DIGITAL OUTPUTS
Output High Voltage, VOH
Output Low Voltage, VOL
START-UP TIME
Initial, Reset Recovery
FLASH MEMORY
Endurance 2
Data Retention 3
CONVERSION RATE SETTING
POWER SUPPLY
Average Supply Current 4
Sleep Mode Current
Min
X, Y
Z
X
Y
Z
−10
+10
+10
TEMP_OUT = 0x0133 (307) at 25°C
Max
+2.7
±1
TBD
24
480
1600
550
5.5
−21
+21
+36
0.244
0
−39
+39
+65
VDD
10
±1
±1
±1
±1
11
±2
±1.25
±2
±3
2.0
VIH = VDD
VIL = 0 V
±0.2
−40
10
ISOURCE = 1.6 mA
ISINK = 1.6 mA
0.8
±1
−60
2.4
2.4
SMPL_PRD = 0x1F, VDD = 2.5 V
1
100
g
mg/LSB
%
%
% FS
Degrees
%
g
mg/°C
mg/V
mg rms
μg/√Hz
Hz
Hz
kHz
LSB
LSB
LSB
°C/LSB
V
Bits
LSB
LSB
LSB
LSB
pF
V
V
μA
μA
pF
0.4
V
V
32
ms
4096
3.6
Cycles
Years
SPS
V
mA
μA
10,000
20
TJ = 85°C
Unit
1
Note that the inputs are 5 V tolerant.
2
Endurance is qualified as per JEDEC Standard 22, Method A117 and measured at −40°C, +25°C, +85°C, and +105°C.
3
Retention lifetime equivalent at junction temperature (TJ) of 55°C as per JEDEC Standard 22, Method A117. Retention lifetime decreases with junction temperature.
Instantaneous current has periodic peaks at the sample rate that can reach 30 mA.
4
Rev. 0 | Page 3 of 16
ADIS16240
TIMING SPECIFICATIONS
TA = 25°C, VDD = 3.3 V, unless otherwise noted.
Table 2.
Parameter
fSCLK
tDATARATE
tCS
tDAV
tDSU
tDHD
tDF
tDR
tSFS
1
2
Min 1
0.01
60
120
Description
Serial clock rate 2
Chip select period2
Chip select to clock edge
Data output valid after SCLK edge
Data input setup time before SCLK rising edge
Data input hold time after SCLK rising edge
Data output fall time
Data output rise time
CS high after SCLK edge
Max1
2.5
Typ
30
20
20
10
10
25
25
430
Unit
MHz
μs
ns
ns
ns
ns
ns
ns
ns
Guaranteed by design; typical specifications are not tested or guaranteed.
Based on sample rate selection.
Timing Diagrams
tDATARATE
08133-002
CS
SCLK
Figure 2. SPI Chip Select Timing
CS
tCS
tSFS
1
2
3
4
5
6
15
16
SCLK
tDAV
MSB
DB14
DB13
tDSU
DIN
W/R
A6
DB12
DB11
A4
A3
DB10
DB2
DB1
LSB
tDHD
A5
A2
D2
D1
Figure 3. SPI Timing (Utilizing SPI Settings Typically Identified as Phase = 1, Polarity = 1)
Rev. 0 | Page 4 of 16
LSB
08133-003
DOUT
ADIS16240
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Acceleration
Any Axis, Unpowered
Any Axis, Powered
VDD to GND
Digital Input Voltage to GND
Analog Inputs to GND
Operating Temperature Range
Storage Temperature Range
Rating
2000 g
2000 g
−0.3 V to +3.6 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−40°C to +85°C
−65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
Rev. 0 | Page 5 of 16
ADIS16240
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
TOP VIEW
1 2
3 4 5 6 7 8
9 10 11
A
H
J
K
L
08133-004
B
C
D
E
F
G
NOTES
1. THE ACTUAL PINS ARE NOT
VISIBLE FROM THE TOP VIEW.
Figure 4. Pin Configuration (Top View)
A1
AZ X
AY
AY
AX
AX
08133-005
AZ
Figure 5. Axis Orientation of Device (Top View)
Table 4. Pin Function Descriptions
Pin No.
E10, E11
F10, F11
G10, G11
H10, H11
J10, J11
K9, L9
K8, L8
K7, L7
K6, L6
K3, L3
J1, J2
H1, H2
G1, G2
A5, B5
D4 to D8, E4, E8, F4, F8, G4, G8, H4 to H8
A1, A2, A10, A11, B1, B2, B10, B11, C3 to C9, D3, D9, E3, E9, F3, F9,
G3, G9, H3, H9, J3 to J9, K1, K2, K10, K11, L1, L2, L10, L11
A3, A4, A6 to A9, B3, B4, B6 to B9, C1, C2, C10, C11, D1, D2, D10,
D11, E1, E2, F1, F2, K4, K5, L4, L5
1
Mnemonic
SCLK
CS
DIN
DOUT
DIO2
DIO1
AN
CMP2
CMP1
RST
XA
YA
ZA
ST
VDD
GND
NC
I = input, O = output, I/O = input/output, S = supply.
Rev. 0 | Page 6 of 16
Type 1
I
I
I
O
I/O
I/O
I
I
I
I
O
O
O
I
S
S
Description
SPI Serial Clock
SPI Chip Select, Active Low
SPI Data Input
SPI Data Output
Multifunction Digital Input/Output 2
Multifunction Digital Input/Output 1
Analog Input Channel
Analog Comparator Input 2
Analog Comparator Input 1
Reset, Active Low, No Pull-Up Resistor
X-Axis Accelerometer Filter Pin
Y-Axis Accelerometer Filter Pin
Z-Axis Accelerometer Filter Pin
Self-Test Input Control Line
Power Supply, 3.3 V
Ground
No Connect
ADIS16240
TYPICAL PERFORMANCE CHARACTERISTICS
2.8
30mA PEAK
2.3
1.8
CURRENT
1
1.3
08133-106
0.8
0.3
0
500
1000
1500 2000 2500 3000
SAMPLE RATE (SPS)
3500
4000
08133-108
SUPPLY CURRENT (mA)
3.3
4500
CH1 20.0V
M40.0µs
A CH1
T
40.5304µs
17.2mV
Figure 9. Instantaneous Supply Current
Figure 6. Supply Current vs. Sample Rate
1.6
1.4
1.0
0.8
CURRENT
0.6
1
0.4
08133-107
0.2
08133-109
SUPPLY CURRENT (mA)
30mA PEAK
1.2
0
2.4
2.6
2.8
3.0
3.2
SUPPLY VOLTAGE (V)
3.4
CH1 50.0V
3.6
Figure 7. Supply Current vs. Supply Voltage
Figure 10. Instantaneous Supply Current
1.5
3.6V
3.0V
1.3
1.2
1.1
2.4V
1.0
08133-110
SUPPLY CURRENT (mA)
1.4
0.9
–40 –30 –20 –10
0 10 20 30 40
TEMPERATURE (°C)
50
60
M40.0µs
A CH1
T
40.5304µs
70
80
90
Figure 8. Supply Current vs. Temperature
Rev. 0 | Page 7 of 16
73.0mV
ADIS16240
THEORY OF OPERATION
The ADIS16240 is a triple-axis accelerometer system for shock
detection and recording applications. This sensing system collects
data autonomously and makes it available to any processor system
that supports a 4-wire serial peripheral interface (SPI).
SENSING ELEMENT
Digital shock sensing starts with the triple-axis MEMS sensing
element in the ADIS16240. This element provides a linear motionto-electrical transducer function. Figure 11 provides a basic
physical diagram of the sensing element and its response to
linear acceleration. It uses a fixed frame and a moving frame to
form a differential capacitance network that responds to linear
acceleration. Tiny springs tether the moving frame to the fixed
frame and govern the relationship between acceleration and
physical displacement. A modulation signal on the moving plate
feeds through each capacitive path into the fixed frame plates
and into a demodulation circuit, which produces the electrical
signal that is proportional to the acceleration acting on the device.
ANCHOR
MOVABLE
FRAME
FIXED
PLATES
UNIT SENSING
CELL
UNIT
FORCING
CELL
Data collection and configuration commands both use the SPI,
which consists of four wires. The chip select (CS) signal activates
the SPI interface, and the serial clock (SCLK) synchronizes the
serial data lines. The serial input data clocks into DIN on the rising
edge of SCLK, and the serial output data clocks out of DOUT on
the falling edge of SCLK. Many digital processor platforms
support this interface with dedicated serial ports and simple
instruction sets.
User Registers
The user registers provide addressing for all input/output
operations on the SPI interface. Each 16-bit register has its own
unique bit assignment and has two 7-bit addresses: one for its
upper byte and one for its lower byte. Table 7 provides a memory
map for each register and identifies output registers as read only
(R) and configuration registers as either read/write (R/W) or write
only (W). The control registers use a dual-memory structure. The
SRAM controls operation while the part is on and facilitates all user
configuration inputs. The flash memory provides nonvolatile storage for the control registers that are identified with a “yes” in the
flash backup column in Table 7. Storing configuration data in the
flash memory requires a manual command (see GLOB_CMD[3]
in Table 24). When the device starts up from an initial power-up
or reset, the flash memory contents load into the SRAM. Then
the device starts producing data according to the configuration
in the control registers.
ANCHOR
MANUAL
FLASH
BACKUP
Figure 11. MEMS Sensor Diagram
DATA SAMPLING AND PROCESSING
(SPI ACCESS)
(NO SPI ACCESS)
The analog acceleration signals feed into an analog-to-digital
converter stage that passes digitized data into the controller for
data processing and capture. The ADIS16240 runs autonomously,
based on the configuration in the user control registers.
START-UP
RESET
Figure 13. Control Registers—SRAM and Flash Memory Diagram
CAPTURE
CAPTURE
BUFFER
CONTROL
REGISTERS
The ADIS16240 offers a recorder function that captures
acceleration information based on either internal or external
triggers. The buffer memory is 3 × 8192 samples and is capable
of storing multiple trigger events.
SPI SIGNALS
MEMS
SENSOR
SPI PORT
OUTPUT
REGISTERS
CONTROLLER
VOLATILE
SRAM
NONVOLATILE
FLASH MEMORY
08133-009
MOVING
PLATE
SPI Interface
08133-007
ACCELERATION
PLATE
CAPACITORS
USER INTERFACE
INPUT/OUTPUT
FUNCTIONS
08133-008
CLOCK
Figure 12. Simplified Sensor Signal Processing Diagram
Rev. 0 | Page 8 of 16
ADIS16240
BASIC OPERATION
User registers govern all data collection and configuration. Table 7
provides a memory map that includes all user registers, along with
references to bit assignment tables that follow the generic assignments in Figure 15.
15
14
13
VDD
VDD
12
11
10
9
8
7
6
UPPER BYTE
5
4
3
2
1
0
08133-011
The ADIS16240 starts up automatically when it has a valid power
supply and begins producing digital acceleration data in the output
registers. When using the factory-default configuration, DIO1
serves as a data-ready indicator signal that can drive a processor
interrupt function. Figure 14 shows a schematic for connecting
to a SPI-compatible processor platform, referred to as the SPI
master.
LOWER BYTE
Figure 15. Generic Register Bit Assignments
SPI Write Commands
ADIS16240
SYSTEM PROCESSOR
SPI MASTER
Master processors write to the control registers, one byte at a
time, using the bit assignments shown in Figure 18. The programmable registers in Table 7 provide controls for optimizing sensor
operation and for starting various automated functions. For
example, set GLOB_CMD[8] = 1 (DIN = 0xCB01) to wake up the
device.
SPI SLAVE
SS
CS
SCLK
SCLK
MOSI
DIN
MISO
DOUT
IRQ1
DIO1
IRQ2
DIO2
08133-010
CS
Figure 14. Electrical Hook-Up Diagram
DIN
Figure 16. SPI Sequence for a Wake-Up Command (DIN = 0xCB01)
Table 5. Generic Master Processor Pin Names and Functions
Some configurations require writing both bytes to a register,
which takes two separate 16-bit sequences. See GLOB_CMD[3]
in Table 24 for backing up configuration data in nonvolatile
flash memory.
Function
Slave select.
Interrupt request inputs.
Master output, slave input.
Master input, slave output.
Serial clock.
SPI Read Commands
The ADIS16240 SPI interface supports full duplex serial communication (simultaneous transmit and receive) and uses the bit
sequence shown in Figure 18. Processor platforms typically support
SPI communication with general-purpose serial ports that require
some configuration in their control registers. Table 6 lists the most
common settings that require attention when initializing a processor serial port for communication with the ADIS16240.
Table 6. Generic Master Processor SPI Settings
Processor Setting
Master
SCLK Rate ≤ 2.5 MHz
SPI Mode 3 (1,1)
MSB First
16-Bit
Description
The ADIS16240 operates as a slave.
Bit rate setting.
Clock polarity/phase (CPOL = 1, CPHA = 1).
Bit sequence.
Shift register/data length.
Reading data on the SPI requires two consecutive 16-bit
sequences. The first sequence transmits the read command on
DIN, and the second sequence receives the resulting data from
DOUT. The 7-bit register address can represent either the upper
or lower byte address for the target register. For example, DIN
can be either 0x0200 or 0x0300 when reading the SUPPLY_OUT
register. The SPI operates in full duplex mode, which means that
the master processor can read the output data from DOUT while
using the same SCLK pulses to transmit a new command on
DIN. In Figure 17, the second SPI segment sets up the device to
read YACCL_OUT on the following SPI segment (not shown).
SPI SEGMENT 1
SPI SEGMENT 2
CS
SCLK
DIN = 0x0600 TO READ YACCL_OUT
DIN
DOUT
DIN = 0x0400 PRODUCES XACCL_OUT CONTENTS ON
DOUT DURING THE NEXT SPI SEGMENT
Figure 17. Example SPI Read Sequence
Rev. 0 | Page 9 of 16
DOUT = 0x802B = 2.21g, NEW DATA
08133-013
Pin Name
SS
IRQ1, IRQ2
MOSI
MISO
SCLK
08133-012
SCLK
ADIS16240
MEMORY MAP
Note that all registers are two bytes. All unused memory locations are reserved for future use.
Table 7. User Register Memory Map
Register
Name
FLASH_CNT
SUPPLY_OUT
XACCL_OUT
YACCL_OUT
ZACCL_OUT
AUX_ADC
TEMP_OUT
XPEAK_OUT
YPEAK_OUT
ZPEAK_OUT
XYZPEAK_OUT
CAPT_BUF1
CAPT_BUF2
DIAG_STAT
EVNT_CNTR
CHK_SUM
XACCL_OFF
YACCL_OFF
ZACCL_OFF
CLK_TIME
CLK_DATE
CLK_YEAR
WAKE_TIME
WAKE_DATE
ALM_MAG1
ALM_MAG2
ALM_CTRL
XTRIG_CTRL
CAPT_PNTR
CAPT_CTRL
GPIO_CTRL
MSC_CTRL
SMPL_PRD
GLOB_CMD
Flash
Backup
Yes
No
No
No
No
No
No
No
No
No
No
Register
Address 1
0x00
0x02
0x04
0x06
0x08
0x0A
0x0C
0x0E
0x10
0x12
0x14
0x16
0x18
0x1A
0x1C
0x1E
0x20
0x22
0x24
0x2E
0x30
0x32
0x34
0x36
0x38
0x3A
0x3C
0x3E
0x40
0x42
0x44
0x46
0x48
0x4A
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Default
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0x0000
0x0000
N/A
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x0000
0x9000
0x9000
0x0000
0x0000
0x0000
0x0022
0x0000
0x0006
0x001F
N/A
Bit
Assignments
N/A
See Table 10
See Table 9
See Table 9
See Table 9
See Table 8
See Table 11
See Table 9
See Table 9
See Table 9
See Table 8
See Table 18
See Table 19
See Table 28
See Table 21
See Table 34
See Table 27
See Table 27
See Table 27
See Table 29
See Table 30
See Table 31
See Table 32
See Table 33
See Table 13
See Table 13
See Table 12
See Table 15
See Table 20
See Table 17
See Table 26
See Table 25
See Table 23
See Table 24
Function
Flash memory write count
Output, power supply
Output, x-axis accelerometer
Output, y-axis accelerometer
Output, z-axis accelerometer
Output, auxiliary ADC input
Output, temperature
Output, x-axis acceleration peak
Output, y-axis acceleration peak
Output, z-axis acceleration peak
Output, sum-of-squares acceleration peak
Output, Capture Buffer 1, X and Y acceleration
Output, Capture Buffer 2, Z acceleration
Diagnostic, error flags
Diagnostic, event counter
Diagnostic, check sum value from firmware test
Calibration, x-axis acceleration offset adjustment
Calibration, y-axis acceleration offset adjustment
Calibration, z-axis acceleration offset adjustment
Clock, hour and minute
Clock, month and day
Clock, year
Wake-up setting, hour and minute
Wake-up setting, month and day
Alarm 1 amplitude threshold
Alarm 2 amplitude threshold
Alarm control
Capture, external trigger control
Capture, address pointer
Capture, configuration and control
General-purpose digital input/output control
Miscellaneous control
Internal sample period (rate) control
System command
Each register contains two bytes. The address of the lower byte is displayed. The address of the upper byte is equal to the address of the lower byte plus 1.
CS
SCLK
DIN
DOUT
R/W
D15
A6
A5
A4
A3
A2
A1
A0
DC7
DC6
DC5
DC4
DC3
DC2
DC1
DC0
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
NOTES
1. DOUT BITS ARE BASED ON THE PREVIOUS 16-BIT SEQUENCE, WHEN R/W = 0.
Figure 18. SPI Communication Bit Sequence
Rev. 0 | Page 10 of 16
R/W
D15
A6
A5
D14
D13
08133-014
1
Read/
Write
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
W
ADIS16240
OUTPUT DATA REGISTERS
Table 9. Accelerometer Data Output Format1
Each output data register uses the bit assignments shown in
Figure 19. The ND flag indicates that unread data resides in the
register. This flag clears and returns to 0 after reading the register.
It returns to 1 after the next internal sample updates the register
with new data. When the data-ready function (the DIO1 and
DIO2 pins and the MSC_CTRL register; see Table 25) drives
data collection, the ND bit is always high and does not require
validation. The EA flag indicates that one of the error flags in the
DIAG_STAT register (see Table 28) is active (true).
Binary
01 0011 0111
…
00 0000 0010
00 0000 0001
00 0000 0000
11 1111 1111
11 1111 1110
…
10 1100 1001
ND
EA
x
x
x
x
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
08133-015
MSB FOR 10-BIT OUTPUT
1
Figure 19. Output Register Bit Assignments
Table 8. Output Data Register Formats
Register
SUPPLY_OUT
XACCL_OUT
YACCL_OUT
ZACCL_OUT
AUX_ADC
TEMP_OUT
XPEAK_OUT1
YPEAK_OUT1
ZPEAK_OUT1
XYZPEAK_OUT2
Bits
10
10
10
10
10
10
10
10
10
12
Format
Binary, 0 V = 0x0000
Twos complement
Twos complement
Twos complement
Binary, 0 V = 0x0000
Binary, 25°C = 0x0133
Twos complement
Twos complement
Twos complement
Binary, 0 g2 = 0x0000
Scale
4.88 mV
51.4 mg
51.4 mg
51.4 mg
VDD/1024
0.244°C
51.4 mg
51.4 mg
51.4 mg
0.676 g2
1
Function requires MSC_CTRL[14] = 1.
2
Function requires MSC_CTRL[15] = 1.
Processing Sensor Data
Processing sensor data starts with reading the appropriate output
data register using the SPI. For example, use DIN = 0x0E00
to read the XPEAK_OUT register. Use the ND and EA bits to
validate new data and normal operating status, if necessary. Then
mask off all of the nondata bits and calculate the data, using the
format and scale information shown in Table 8. For example,
XACCL_OUT[9:0] and XYZPEAK_OUT[11:0] contain all
relevant data for their function. Table 9, Table 10, and Table 11
provide output code examples for each output register.
Hex
0x137
…
0x002
0x001
0x000
0x3FF
0x3FE
…
0x2C9
Codes
+311
…
+2
+1
0
−1
−2
…
−311
Acceleration
+16 g
…
+102.8 mg
+51.4 mg
0
−51.4 mg
−102.8 mg
…
−16 g
The XACCL_OUT register is located at Address 0x05[15:8] and Address 0x04[7:0].
The YACCL_OUT register is located at Address 0x07[15:8] and Address 0x06[7:0].
The ZACCL_OUT register is located at Address 0x09[15:8] and Address 0x08[7:0].
The XPEAK_OUT register is located at Address 0x0F[15:8] and Address 0x0E[7:0].
The YPEAK_OUT register is located at Address 0x11[15:8] and Address 0x10[7:0].
The ZPEAK_OUT register is located at Address 0x13[15:8] and Address 0x12[7:0].
When MSC_CTRL[14] = 1, the XPEAK_OUT, YPEAK_OUT,
and ZPEAK_OUT registers track the peak acceleration in each
acceleration output register. When MSC_CTRL[15] = 1, use the
following equation to calculate the root mean square (rms) of all
three peak registers, where 1 LSB = 0.822 g:
XYZrms =
XYZPEAK _ OUT
Set GLOB_CMD[5] = 1 to reset these registers to 0x0000.
Table 10. Power Supply Data Output Format1
Binary
10 1110 0010
…
10 1010 0101
10 1010 0100
10 1010 0011
…
01 1110 1100
1
Hex
0x2E2
…
0x2A5
0x2A4
0x2A3
…
0x1EC
Codes
738
…
677
676
675
…
492
Power Supply (V)
3.6
…
3.30488
3.3
3.29502
…
2.4
The SUPPLY_OUT register is located at Address 0x03[15:8] and Address 0x02[7:0].
Table 11. Temperature Data Output Format1
Binary
10 0010 1001
…
01 0011 0100
01 0011 0011
01 0011 0010
…
00 0010 1001
1
Hex
0x229
…
0x134
0x133
0x132
…
0x029
Codes
553
…
308
307
306
…
41
Temperature (°C)
+85°C
…
+25.244°C
+25°C
+24.756°C
…
−40°C
The TEMP_OUT register is located at Address 0x0D[15:8] and Address 0x0C[7:0].
Rev. 0 | Page 11 of 16
ADIS16240
EVENT RECORDER
The ADIS16240 provides a 3 × 8192 (8-bit) buffer memory for
reading transient acceleration data on all three axes (x, y, and z).
There are a number of user controls for tailoring the event recorder
for optimal system-level operation. Alarm 1 and Alarm 2 provide
internal and external trigger options for starting a data capture
sequence.
Internal Trigger Setup
Select the trigger data source for Alarm 1 and Alarm 2 using
ALM_CTRL[15:8] (see Table 12). The ALM_MAG1 and ALM_
MAG2 registers contain threshold magnitude and direction
settings for Alarm 1 and Alarm 2, respectively. The format for
the data bits in these registers matches the trigger data source,
which is set using ALM_CTRL[15:8]. For example, if ALM_
CTRL[15:12] equals 0010, then the format matches that of
XACCL_OUT: 10-bit, twos complement, with 1 LSB = 51.4 mg
of acceleration.
Table 12. ALM_CTRL Register Bit Descriptions1
Bit
[15:12]
[11:8]
[7:6]
5
4
3
2
1
0
1
Description (Default = 0x0000)
Alarm 2 source selection
0000 = disabled
0001 = power supply voltage (SUPPLY_OUT)
0010 = x acceleration (XACCL_OUT)
0011 = y acceleration (YACCL_OUT)
0100 = z acceleration (ZACCL_OUT)
0101 = auxiliary ADC voltage (AUX_ADC)
0110 = temperature (TEMP_OUT)
0111 = XYZ peak acceleration (XYZPEAK_OUT)
1000 = external trigger
Alarm 1 source selection (same as Alarm 2)
Unused
Alarm 2 capture trigger: 1 = enabled, 0 = disabled
Alarm 1 capture trigger: 1 = enabled, 0 = disabled
Unused
Alarm indicator enable: 1 = enabled, 0 = disabled
Alarm indicator polarity: 1 = positive, 0 = negative
Alarm indicator pin: 1 = DIO2, 0 = DIO1
1
Description
Set Alarm 1 and Alarm 2 to ZACCL_OUT
Set Alarm 1 to trigger on a measured acceleration
that has a magnitude of >2.57 g
Set Alarm 2 to trigger on a measured acceleration
that has a magnitude of <0.5 g
Activate Alarm 1 and Alarm 2 to trigger capture events,
and configure DIO2 as a positive alarm indicator output.
External Trigger Setup
ALM_CTRL[15:8] and XTRIG_CTRL (see Table 15) provide all
of the settings needed to govern the use of the comparator pins
(CMP1, CMP2) as external trigger inputs.
Table 15. XTRIG_CTRL Register Bit Descriptions1
Bit
[15:8]
7
6
5
4
[3:0]
Description (Default = 0x0000)
Unused
External Trigger 1 direction: 0 = <, 1 = >
External Trigger 2 direction: 0 = <, 1 = >
External Trigger 1 enable: 1 = enabled, 0 = disabled
External Trigger 2 enable: 1 = enabled, 0 = disabled
External trigger-level setting (TL), binary format
Note that trigger threshold = TL × supply/24
The XTRIG_CTRL register is located at Address 0x3F[15:8] and Address 0x3E[7:0].
Table 16. External Trigger Setup Example
DIN
0xBD80
0xBE1C
0xBC20
Description
Set Alarm 2 to an external trigger (ALM_CTRL)
Activate and set CMP2 to trigger on signals that are
greater than one-half of the supply voltage (XTRIG_CTRL)
Activate Alarm 2 to trigger data capture (ALM_CTRL)
If the device is in standby mode, an external trigger on CMD1 or
CMD2 awakens the device and initiates an event capture. The first
sample is taken 0.2 ms + sample period (SMPL_PRD[7:0]) after
the trigger edge.
Buffer Memory Configuration
Table 13. ALM_MAG1, ALM_MAG2 Register Bit Descriptions1
14
[13:0]
DIN
0xBD44
0xB980,
0xB832
0xBB00,
0xBA0A
0xBC37
1
The ALM_CTRL register is located at Address 0x3D[15:8] and Address 0x3C[7:0].
Bit
15
Table 14. Internal Trigger Setup Example
Description (Default = 0x9000)
Threshold direction
1 = active for output greater than alarm magnitude
0 = inactive for output less than alarm magnitude
Unused
Trigger threshold; bit format matches that of the
register selected by ALM_CTRL[15:8] but is unsigned.
The ALM_MAG1 register is located at Address 0x39[15:8] and Address 0x38[7:0].
The ALM_MAG2 register is located at Address 0x3B[15:8] and Address 0x3A[7:0].
CAPT_CTRL (see Table 17) manages the buffer memory for the
event recorder using two programmable controls: event length and
pretrigger length.
Table 17. CAPT_CTRL Register Bit Descriptions1
Bit
[15:8]
[7:4]
3
[2:0]
1
Description (Default = 0x0022)
Unused
Pretrigger length control factor (P), binary format
Unused
Event length control factor (T), binary format
The CAPT_CTRL register is located at Address 0x43[15:8] and Address 0x42[7:0].
The event length (NL) also determines the number of events (NE)
that the buffer can store at one time.
Rev. 0 | Page 12 of 16
ADIS16240
Table 18. CAPT_BUF1 Register Bit Descriptions1
NL
EVENT 2
8192
SAMPLES
NL =
Bit
[15:8]
[7:0]
1024
2T
NE = 8 × 2T
EVENT NE
08133-016
EVENT 1
1
Figure 20. Event Storage in Buffer Memory
Event Organization
Each event contains a header, pretrigger data, and posttrigger data,
as shown in Figure 21. The event header provides information
about the conditions that occur when the capture takes place.
CAPT_CTRL[7:4] sets the number of pretrigger samples in
each event. If NPRE is negative, there is no pretrigger data and
the first sample after the trigger follows the header.
The CAPT_BUF1 register is located at Address 0x17[15:8] and Address 0x16[7:0].
Bit
[15:8]
[7:0]
1
Description
Unused
Z-axis acceleration
The CAPT_BUF2 register is located at Address 0x19[15:8] and Address 0x18[7:0].
Bit
[15:13]
[7:0]
Description
Unused
Buffer address that loads into CAPT_BUF1, CAPT_BUF2
The CAPT_PNTR register is located at Address 0x41[15:8] and Address 0x40[7:0].
CAPT_BUF2
BUFFER 1
0
XYZPEAK_OUT
0
0
TIME
1
0
DATE
2
0
TEMP_OUT
3
0
SUPPLY_OUT
4
0
AUX_ADC
5
0
Z–26
Y–26
X–26
6
0
Z–25
Y–25
X–25
7
0
Z–1
Y–1
X–1
31
0
Z0
Y0
X0
32
0
Z1
Y1
X1
33
Z223
Y223
X223
255
CAPT_BUF1
EVENT
HEADER
0
0
BUFFER 1
CAPT_PNTR
USER ACCESIBLE
Figure 21. Default Event Organization
INTERNAL MEMORY STRUCTURE
Reading Event Data
The CAPT_BUF1, CAPT_BUF2, and CAPT_PNTR registers
manage user access to data in the capture buffer (see Table 18,
Table 19, and Table 20). The address pointer, CAPT_PNTR,
determines which capture memory location loads into the capture
buffer registers. It increments automatically with every CAPT_
BUF2 read. The most efficient method for reading the entire
buffer memory space is to alternate between the CAPT_BUF1
(DIN = 0x9600) and CAPT_BUF2 (DIN = 0x9800) read commands. When alternating the read sequences in this manner,
the CAP_PNTR increments automatically and optimizes SPI
processing resources. Writing to the CAPT_PNTR register provides access to individual locations in the capture. For example,
writing 0x0138 (DIN = 0xC038, DIN = 0xC101) to the CAPT_
PNTR register causes the 311th sample in each buffer memory
to load into the CAP_BUF1 and CAPT_BUF2 locations (see
Figure 22).
08133-018
0
BUFFER 2
08133-017
POSTTRIGGER
DATA
BUFFER 2
Format
Twos complement,
205.7 mg/LSB
Table 20. CAPT_PNTR Register Bit Descriptions1
1
NL
−6
16
PRETRIGGER
DATA
Format
Twos complement,
205.7 mg/LSB
Table 19. CAPT_BUF2 Register Bit Descriptions1
For example, if CAPT_CTRL[2:0] = 100, then T = 4, which
organizes the buffer memory into 128 events of 64 samples each.
N PRE =
Description
Y-axis acceleration
X-axis acceleration
Figure 22. Capture Buffer Data Flow Diagram
The EVNT_CNTR register (see Table 21) provides a running count
for the number of triggers (internal and external) that occur after
a buffer clear and/or reset. If this number is greater than the
number of events, this indicates that the device has experienced
trigger events that it could not capture because its capture buffer
is full. The EVNT_CNTR returns to 0x0000 after a buffer clear
(GLOB_CMD[6] = 1 by DIN = 0xCA40), or a factory reset
(GLOB_CMD[1] = 1 by DIN = 0xCA02). After a power cycle or
software reset command, the EVNT_CNTR contains the number
of events stored in the buffer memory.
Table 21. EVNT_CNTR Register Bit Descriptions1
Bit
[15:0]
1
Description
Binary event counter
The EVNT_CNTR register is located at Address 0x1D[15:8] and Address 0x1C[7:0].
Rev. 0 | Page 13 of 16
ADIS16240
Transient Behavior During Capture
During capture events, the device consumes an increased amount
of current for a short period. Following a capture event, sampling
suspends and the SPI commands are ignored by the sensor for
the pause times that are listed in Table 22.
purpose lines, the GPIO_CTRL register configures DIO1 and
DIO2. For example, set GPIO_CTRL = 0x0103 (DIN = 0xC403,
then 0xC501) to set DIO1 and DIO2 as outputs, with DIO1 in
a 1 state and DIO2 in a 0 state. In the event of competing assignments, the order of precedence is MSC_CTRL, ALM_CTRL,
and GPIO_CTRL.
Table 22. Postcapture Operation Pause Times
Event Length (Samples)
<64
128
256
512
1024
Table 24. GLOB_CMD Register Bit Descriptions1
Pause Time (ms)
2
4
8
16
33
OPERATIONAL CONTROL
Internal Sample Rate
The SMPL_PRD register (see Table 23) provides a user control
for sample rate adjustment, using the following equation:
fS =
32768
(N SR + 1)
1
2
For example, set SMPL_PRD[7:0] = 0x07 (DIN = 0xC807) to
configure the ADIS16240 to operate at its maximum sample
rate of 4096 SPS. Note that the sample rate affects power dissipation and peak resolution during event capture.
Table 23. SMPL_PRD Register Bit Descriptions1
Bit
[15:0]
1
Bit
[15:9]
8
7
6
5
4
3
2
1
0
Description (Default = 0x001F)
Sample rate scale factor, binary format (NSR)
The SMPL_PRD register is located at Address 0x49[15:8] and Address 0x48[7:0].
Global Commands
For convenience, the GLOB_CMD register (see Table 24) provides
an array of single-write commands. Setting the assigned bit to 1
activates each function, right after the 16th SCLK in the SPI communication sequence. When the function completes, the bit
restores itself to 0. All commands in the GLOB_CMD register
require the power supply to be within normal limits for the
execution times listed in Table 24. The execution times reflect the
factory default configuration, where applicable, and describe the
time required to return to normal operation. For example, set
GLOB_CMD[2] = 1 (DIN = 0xCA04) to place the part in standby
mode. Set GLOB_CMD[8] = 1 (DIN = 0xCB01) to wake up the
device and return to normal operation.
Execution Time2
N/A
0.2 ms
32 ms
350 ms
N/A
N/A
24 ms
N/A
350 ms
N/A
The GLOB_CMD register is located at Address 0x4B[15:8] and Address 0x4A[7:0].
SPI processing and data sampling suspend for the indicated times.
Table 25. MSC_CTRL Register Bit Descriptions1
Bit
15
14
[13:10]
9
8
[7:3]
2
1
0
1
Description (Default = 0x0006)
Enables sum-of-squares output (XYZPEAK_OUT)
Enables peak tracking output (XPEAK_OUT,
YPEAK_OUT, and ZPEAK_OUT)
Unused
No self-test on startup when set to 1
Self-test enable: 1 = apply electrostatic force, 0 = disabled
Unused
Data-ready enable: 1 = enabled, 0 = disabled
Data-ready polarity: 1 = active high, 0 = active low
Data-ready line selection: 1 = DIO2, 0 = DIO1
The MSC_CTRL register is located at Address 0x47[15:8] and Address 0x46[7:0].
Table 26. GPIO_CTRL Register Bit Descriptions1
Bit
[15:10]
9
8
[7:2]
1
0
Input/Output Lines
The ADIS16240 provides two general-purpose digital input/
output lines that offer several functions. When using the factorydefault configuration, MSC_CTRL[2:0] establishes DIO1 as
a positive data-ready output. Change MSC_CTRL[2:0] to 100
(DIN = 0xC604) to make DIO1 a negative data-ready output
signal. ALM_CTRL[2:0] offers a control for setting one of the
digital signals as an alarm indicator. For example, set ALM_
CTRL[2:0] = 110 (DIN = 0xBC06) to set DIO1 as a positive
alarm indicator output signal. When configured as general-
Description
Unused
Wake up from standby mode
Software reset
Clear capture buffer flash memory
Clear peak registers
Clear DIAG_STAT register
Save configuration to flash
Start standby mode for low power
Restore factory-default settings
Auto-null
1
Description (Default = 0x0000)
Unused
General-Purpose I/O Line 2 data level
General-Purpose I/O Line 1 data level
Unused
General-Purpose I/O Line 2, data direction control:
1 = output, 0 = input
General-Purpose I/O Line 1, data direction control:
1 = output, 0 = input
The GPIO_CTRL register is located at Address 0x45[15:8] and Address 0x44[7:0].
Offset Adjustment
The XACCL_OUT, YACCL_OFF, and ZACCL_OFF registers
add to the sensor outputs and provide a convenient offset adjustment function for each accelerometer output. For example, writing
0x0A to YACCL_OUT[7:0] (DIN = 0xA20A) results in a 514 mg
offset adjustment for the YACCL_OUT output data.
Rev. 0 | Page 14 of 16
ADIS16240
Table 27. XACCL_OFF, YACCL_OFF, ZACCL_OFF1
Table 30. CLK_DATE Register Bit Descriptions1
Bit
[15:10]
[9:0]
Bit
[15:13]
12
[11:8]
[7:6]
[5:4]
[3:0]
1
Description (Default = 0x0000)
Unused
Offset, twos complement, 51.4 mg/LSB
The XACCL_OFF register is located at Address 0x21[15:8] and Address 0x20[7:0].
The YACCL_OFF register is located at Address 0x23[15:8] and Address 0x22[7:0].
The ZACCL_OFF register is located at Address 0x25[15:8] and Address 0x24[7:0].
Diagnostics
For all of the error flags in the DIAG_STAT register (see Table 28),
a 1 identifies an error condition, and a 0 signals normal operation.
All of the flags return to 0 after reading DIAG_STAT. If the power
supply is still out of range during the next sample cycle, DIAG_
STAT[0] and DIAG_STAT[1] return to 1. DIAG_STAT[9:8] provide flags to check for the alarms with respect to the conditions in
the ALM_CTRL and ALM_MAGx registers. DIAG_STAT[6]
contains the internal memory checksum result. If the sum of the
firmware program memory does not does not match the expected
value, this flag reports a 1. The SPI communication flag (DIAG_
STAT[3]) changes to 1 when the number of SCLK pulses during
a SPI transfer is not a multiple of 16 when CS goes high.
Table 28. DIAG_STAT Register Bit Descriptions1
Bit
[15:10]
9
8
7
6
5
4
3
2
1
0
1
Description (Default = 0x0000)
Unused
Alarm 2 status: 1 = alarm active, 0 = alarm inactive
Alarm 1 status: 1 = alarm active, 0 = alarm inactive
Capture buffer full: 1 = capture buffer is full
Flash test, checksum flag: 1 = mismatch, 0 = match
Power-on, self-test flag: 1 = failure, 0 = pass
Power-on self-test: 1 = in-progress, 0 = complete
SPI communications failure: 1 = error, 0 = normal
Flash update failure: 1 = failure, 0 = pass
Power supply above 3.625 V: 1 = above, 0 = below
Power supply below 2.225 V: 1 = below, 0 = above
Table 31. CLK_YEAR Register Bit Descriptions1
Bit
[15:8]
[7:4]
[3:0]
1
Description (Default = 0x0000)
Unused
Year, 10s digit
Year, 1s digit
The CLK_YEAR register is located at Address 0x33[15:8] and Address 0x32[7:0].
The WAKE_TIME and WAKE_DATE registers enable users
to program a specific time for the ADIS16240 to exit standby
mode. Enable this function by writing the wake-up time and
date to these registers.
Bit
15
14
[13:12]
[11:8]
7
[6:4]
[3:0]
1
Description (Default = 0x0000)
Wake time enable (1 = enabled, 0 = disabled)
Unused
Hours, 10s digit
Hours, 1s digit
Unused
Minutes, 10s digit
Minutes, 1s digit
The WAKE_TIME register is located at Address 0x35[15:8] and Address 0x34[7:0].
Table 33. WAKE_DATE Register Bit Descriptions1
Clock
The CLK_TIME, CLK_DATE, and CLK_YEAR registers provide
an internal clock that enables a time entry into the event header
and for user access. If CLK_TIME = 0x2231, the time is 22:31,
or 10:31 p.m. The CLK_DATE and CLK_YEAR registers follow
a similar binary-coded, decimal format.
Bit
[15:14]
[13:12]
[11:8]
[7:6]
[5:4]
[3:0]
1
Table 29. CLK_TIME Register Bit Descriptions1
1
The CLK_DATE register is located at Address 0x31[15:8] and Address 0x30[7:0].
Table 32. WAKE_TIME Register Bit Descriptions1
The DIAG_STAT register is located at Address 0x1B[15:8] and Address 0x1A[7:0].
Bit
[15:14]
[13:12]
[11:8]
7
[6:4]
[3:0]
1
Description (Default = 0x0000)
Unused
Month, 10s digit
Month, 1s digit
Unused
Day, 10s digit
Day, 1s digit
Description
Unused
Hours, 10s digit
Hours, 1s digit
Unused
Minutes, 10s digit
Minutes, 1s digit
Description (Default = 0x0000)
Unused
Month, 10s digit
Month, 1s digit
Unused
Day, 10s digit
Day, 1s digit
The WAKE_DATE register is located at Address 0x37[15:8] and Address 0x36[7:0].
Checksum
Table 34. CHK_SUM Register Bit Descriptions1
Bit
[15:0]
1
Description
Sum of memory locations used to verify code integrity
The CHK_SUM register is located at Address 0x1F[15:8] and Address 0x1E[7:0].
The CLK_TIME register is located at Address 0x2F[15:8] and Address 0x2E[7:0].
Rev. 0 | Page 15 of 16
ADIS16240
OUTLINE DIMENSIONS
12.10
12.00 SQ
11.90
A1 BALL
CORNER
11 10 9 8 7 6 5 4
3 2 1
A
B
C
D
E
F
G
BALL A1
PAD CORNER
10.00
BSC SQ
H
J
K
L
1.00
BSC
BOTTOM VIEW
TOP VIEW
2.90
2.80
2.70
DETAIL A
DETAIL A
2.30 NOM
0.50 NOM
COPLANARITY
0.10
SEATING
PLANE
010909-A
0.65
0.60
0.55
BALL DIAMETER
Figure 23. 112-Ball Plastic Ball Grid Array [PBGA]
(B-112-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADIS16240ABCZ 1
ADIS16240/PCBZ1
1
Temperature Range
−40°C to +85°C
Package Description
112-Ball Plastic Ball Grid Array [PBGA]
Evaluation Board
Z = RoHS Compliant Part.
©2009 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D08133-0-4/09(0)
Rev. 0 | Page 16 of 16
Package Option
B-112-1