ADIS16375 Data Sheet
Rev. E | Page 20 of 28
CALIBRATION
The ADIS16375 factory calibration produces correction formulas
for each gyroscope and accelerometer, and then programs them
into the flash memory. Table 58 contains a list of user control
registers that provide opportunity for user optimization after
installation. The bias and scale correction registers are in Page 2,
and the control registers are in Page 3. Figure 20 illustrates an
example of how the scale and offset registers for each sensor
function.
Table 58. Registers for User Calibration
Register Page Address Correction Function
XGYRO_OFF_L 2 0x10 Offset, X-axis gyroscope
XGYRO_OFF_H 2 0x12 Offset, X-axis gyroscope
YGYRO_OFF_L 2 0x14 Offset, Y-axis gyroscope
YGYRO_OFF_H 2 0x16 Offset, Y-axis gyroscope
ZGYRO_OFF_L 2 0x18 Offset, Z-axis gyroscope
ZGYRO_OFF_H 2 0x1A Offset, Z-axis gyroscope
XACCL_OFF_L 2 0x1C Offset, X-axis accelerometer
XACCL_OFF_H 2 0x1E Offset, X-axis accelerometer
YACCL_OFF_L 2 0x20 Offset, Y-axis accelerometer
YACCL_OFF_H 2 0x22 Offset, Y-axis accelerometer
ZACCL_OFF_L 2 0x24 Offset, Z-axis accelerometer
ZACCL_OFF_H 2 0x26 Offset, Z-axis accelerometer
XGYRO_SCL 2 0x40 Scale, X-axis gyroscope
YGYRO_SCL 2 0x42 Scale, Y-axis gyroscope
ZGYRO_SCL 2 0x44 Scale, Z-axis gyroscope
XACCL_SCL 2 0x46 Scale, X-axis accelerometer
YACCL_SCL 2 0x48 Scale, Y-axis accelerometer
ZACCL_SCL 2 0x4A Scale, Z-axis accelerometer
GEN_CONFIG 3 0x0A Calibration configuration
NULL_CFG 3 0x0E Bias-null configuration
GLOB_CMD 3 0x02 Calibration commands
The factory calibration addresses initial and temperature dependent
bias errors in the gyroscopes, but some environmental conditions,
such as temperature cycling and mechanical stress on the package,
can cause bias shifts in MEMS gyroscope structures. For systems
that value absolute bias accuracy, there are two options for
optimizing absolute bias accuracy: autonull and manual correction.
Manual Bias Correction
The xGYRO_OFF_H (see Table 59, Table 60, and Table 61) and
xGYRO_OFF_L (see Table 62, Table 63, and Table 64) registers
provide a bias adjustment function for the output of each gyro-
scope sensor. The xGYRO_OFF_H registers use the same format
as x_GYRO_OUT registers. The xGYRO_OFF_L registers use
the same format as x_GYRO_LOW registers.
Table 59. XGYRO_OFF_H (Page 2, Base Address = 0x12)
Bits Description (Default = 0x0000)
[15:0]
X-axis gyroscope offset correction, upper word; uses
same format as X_GYRO_OUT (see Table 11)
Table 60. YGYRO_OFF_H (Page 2, Base Address = 0x16)
Bits Description (Default = 0x0000)
[15:0]
Y-axis gyroscope offset correction, upper word; uses
same format as Y_GYRO_OUT (see Table 12)
Table 61. ZGYRO_OFF_H (Page 2, Base Address = 0x1A)
Bits Description (Default = 0x0000)
[15:0]
Z-axis gyroscope offset correction, upper word; uses
same format as Z_GYRO_OUT (see Table 13)
Table 62. XGYRO_OFF_L (Page 2, Base Address = 0x10)
Bits Description (Default = 0x0000)
[15:0]
X-axis gyroscope offset correction, lower word; uses
same format as X_GYRO_LOW (see Table 15)
Table 63. YGYRO_OFF_L (Page 2, Base Address = 0x14)
Bits Description (Default = 0x0000)
[15:0]
Y-axis gyroscope offset correction, lower word; uses
same format as Y_GYRO_LOW (see Table 16)
Table 64. ZGYRO_OFF_L (Page 2, Base Address = 0x18)
Bits Description (Default = 0x0000)
[15:0]
Z-axis gyroscope offset correction, lower word; uses
same format as Z_GYRO_LOW (see Table 17)
The xACCL_OFF_H (see Table 65, Table 66, and Table 67) and
xACCL_OFF_L (see Table 68, Table 69, and Table 70) registers
provide a bias adjustment function for the output of each gyroscope
sensor. The xACCL_OFF_H registers use the same format as
x_ACCL_OUT registers. The xACCL_OFF_L registers use the
same format as x_ACCL_LOW registers.
Table 65. XACCL_OFF_H (Page 2, Base Address = 0x1E)
Bits Description (Default = 0x0000)
[15:0]
X-axis accelerometer offset correction, upper word;
uses same format as X_ACCL_OUT (see Table 18)
Table 66. YACCL_OFF_H (Page 2, Base Address = 0x22)
Bits Description (Default = 0x0000)
[15:0]
Y-axis accelerometer offset correction, upper word;
uses same format as Y_ACCL_OUT (see Table 19)
Table 67. ZACCL_OFF_H (Page 2, Base Address = 0x26)
Bits Description (Default = 0x0000)
[15:0]
Z-axis accelerometer offset correction, upper word;
uses same format as Z_ACCL_OUT (see Table 20)
Table 68. XACCL_OFF_L (Page 2, Base Address = 0x1C)
Bits Description (Default = 0x0000)
[15:0]
X-axis accelerometer offset correction, lower word;
uses same format as X_ACCL_LOW (see Table 22)
Table 69. YACCL_OFF_L (Page 2, Base Address = 0x20)
Bits Description (Default = 0x0000)
[15:0]
Y-axis accelerometer offset correction, lower word;
uses same format as Y_ACCL_LOW (see Table 23)
