ADIS16354AMLZ Analog Devices Inc, ADIS16354AMLZ Datasheet - Page 17

• Manufacturer Part Number: ADIS16354AMLZ
• Description: MODULE GYRO/ACCELEROMETER 24LD
• Manufacturer: Analog Devices Inc
• Series: iSensor™r

Specifications of ADIS16354AMLZ

• Output Type: Digital - SPI
• Sensor Type: Gyroscope and Accelerometer
• No. Of Axes: 3
• Sensor Case Style: ML-24-2
• No. Of Pins: 24
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Acceleration Range: ± 1.7g
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With: ADIS16354/PCBZ - BOARD EVAL FOR ADIS16354
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

CALIBRATION
For applications that require point-of-use calibration, the
ADIS16354 provides bias correction registers for all six sensors.
Table 11, Table 12, Table 13, and Table 14 provide the details
required for using these registers to calibrate the ADIS16354
sensors.
Table 11. Gyroscope Bias Correction Registers
Register
XGYRO_OFF
YGYRO_OFF
ZGYRO_OFF
Table 12. Gyroscope Bias Correction Register Bits
Bits
[15:13]
[12:0]
Table 13. Accelerometer Bias Correction Registers
Register
XACCL_OFF
YACCL_OFF
ZACCL_OFF
Table 14. Accelerometer Bias Correction Register Bits
Bits
[15:12]
[11:0]
Manual Bias Calibration
Because each offset bias register has read/write access, the bias
of each sensor is adjustable. For example, if an output offset of
0.18°/s is observed in the Z-axis gyroscope, the ZGYRO_OFF
register provides the calibration factor necessary to improve the
accuracy. Using its sensitivity of 0.018315°/s, an adjustment of
−10 LSBs is required. The twos complement, hexadecimal code
of −10 LSBs is 0x1FF6.
To implement this calibration factor, use the following
pseudocode:
This step reduces the 0.18°/s error term to 0.00315°/s.
Automatic Bias Null Calibration
The ADIS16354 provides a single-command, automatic bias
calibration for all three gyroscope sensors. The COMMAND
register provides this function, which measures all three
gyroscope output registers, then loads the three bias correction
registers with values that return their outputs to zero (null). A
single register write command starts this process (see Table 16).
Write 0xF6 to Address 0x1E, then write 0x1F to Address 0x1F
Write 0x01 to Address 0x3E
Addresses
Addresses
0x23, 0x22
0x25, 0x24
0x1B, 0x1A
0x1D, 0x1C
0x1F, 0x1E
0x21, 0x20
Description
Not used
Data bits, typical adjustment range = ±947 mg
Description
Not used
Data bits, typical adjustment range = ±75°
Common Parameters
Default value = 0x0000
Scale = 0.018315°/s per LSB
Twos complement, read/write
Common Parameters
Default value = 0x0000
Scale = 0.4672 mg per LSB
Twos complement, read/write
Rev. A | Page 17 of 17
Precision Automatic Bias Null Calibration
The ADIS16354 also provides a single-command function that
incorporates the optimal averaging time for generating the
appropriate bias correction factors for all three gyroscope sensors.
This command requires approximately 30 seconds to complete.
For optimal calibration accuracy, the device should be stable
(no motion) for this entire period. Once it has started, a reset
command is required to stop it prematurely, if required. The
following sequence starts this calibration option (see Table 16):
Restoring Factory Calibration
The ADIS16354 factory calibration can be restored by returning
the contents of each bias correction register to their default
value of zero. This command also flushes all of the data from
the digital filter taps. To accomplish this function for all six
sensor signal paths (see Table 16),
Linear Acceleration Bias Compensation (Gyroscopes)
The ADIS16354 provides compensation for acceleration
influences on the gyroscopes’ bias behavior, using the
MSC_CTRL register.
Linear Acceleration Origin Alignment
The ADIS16354 provides origin alignment for the accelerometers
to the point of percussion (see Figure 5), using the MSC_CTRL
register.
GLOBAL COMMANDS
The ADIS16354 provides global commands for common
operations such as calibration, flash update, auxiliary DAC
latch, and software reset. Each global command has a unique
control bit assigned to it in the COMMAND register and is
initiated by writing a 1 to its assigned bit.
The flash update command writes the contents of each non-
volatile register into flash memory for storage. This process
takes approximately 100 ms and requires the power supply
voltage to be within specification for the duration of the event.
Note that this operation also automatically follows the autonull,
precision autonull, and factory reset commands. After waiting
the appropriate time for the flash update to complete, verify
successful completion by reading the STATUS register (flash
update error = 0, if successful).
The DAC latch command loads the contents of AUX_DAC into
the DAC latches, which control the actual output level. This
overcomes the challenge of discontinuous outputs that would
otherwise be associated with two separate write cycles for upper
and lower bytes. Finally, the software reset command sends the
ADIS16354 digital processor into a restart sequence, effectively
accomplishing the same tasks as the RST line.
Write 0x10 to Address 0x3E
Write 0x02 to Address 0x3E
Set Bit 7 of Address 0x34 to 1 (see Table 29)
Set Bit 6 of Address 0x34 to a 1 (see Table 29)
ADIS16354