ADIS16300/PCBZ Analog Devices Inc, ADIS16300/PCBZ Datasheet - Page 11

• Manufacturer Part Number: ADIS16300/PCBZ
• Description: BOARD EVAL ADIS16300
• Manufacturer: Analog Devices Inc
• Type: Accelerometerr

Specifications of ADIS16300/PCBZ

• Contents: Evaluation Board
• For Use With/related Products: ADIS16300
• For Use With: ADISUSBZ - KIT EVAL ADIS W/SOFTWARE USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OUTPUT DATA REGISTERS
Figure 6 provides the positive measurement direction for each
inertial sensor (gyroscope and accelerometers). Table 9 provides
the configuration and scale factor for each output data register
in the ADIS16300. All inertial sensor outputs are 14-bits in
length and are in twos complement format, which means that
0x0000 is equal to 0 LSB, 0x0001 is equal to +1 LSB, and 0x3FFF
is equal to −1 LSB. The following is an example of how to
calculate the sensor measurement from the GYRO_OUT:
Therefore, a GYRO_OUT output of 0x3B4A corresponds to a
clockwise rotation about the z-axis (see Figure 6) of 60.3°/sec
when looking at the top of the package.
Table 9. Output Data Register Formats
Register
SUPPLY_OUT
GYRO_OUT
XACCL_OUT
YACCL_OUT
ZACCL_OUT
TEMP_OUT
ROLL_OUT
PITCH_OUT
AUX_ADC
1
Each output data register uses the bit assignments shown in
Figure 13. The ND flag indicates that unread data resides in the
output data registers. This flag clears and returns to 0 during an
output register read sequence. It returns to 1 after the next
internal sample updates the registers with new data. The EA flag
indicates that one of the error flags in the DIAG_STAT register
(see Table 21) is active (true). The remaining 14-bits are for data.
Inclinometers
The ROLL_OUT and PITCH_OUT registers provide a tilt angle
calculation, based on the accelerometers. The zero reference is
the point at which the z-axis faces gravity for a north-east-down
(NED) configuration.
ROLL
PITCH
Assumes that the scaling is set to ± 300°/sec. This factor scales with the range.
GYRO_OUT
0x000
−
Rate
_
0x04B6
_
OUT
ND EA
OUT
=
1
−
0.05
=
=
0x33B4A
a
Figure 13. Output Register Bit Assignments
a
tan
=
tan
°
Bits
12
14
14
14
14
12
13
13
12
−
/sec
⎛
⎜ ⎜
⎝
1206
⎛
⎜ ⎜
⎝
=
YACCL
ZACCL
YACCL
0x3B4A
×
(
=
Format
Binary, 5 V = 0x0814
Twos complement
Twos complement
Twos complement
Twos complement
Twos complement
25°C = 0x0000
Twos complement
Twos complement
Binary, 1 V = 0x04D9
LSB
−
MSB FOR 14-BIT OUTPUT
_
−
_
1206
_
OUT
0x04B6
OUT
OUT
MSB FOR 12-BIT OUTPUT
)
⎞
⎟ ⎟
⎠
=
x
=
−
−
sin(
φ
XACCL
=
60.3
−
φ
)
(
4
°
+
/sec
×
ZACCL
_
256
OUT
+
_
11
OUT
Scale
2.42 mV
0.05°/sec
0.6 mg
0.6 mg
0.6 mg
0.14°C
0.044°
0.044°
0.81 mV
×
16
x
+
cos
6
Rev. A | Page 11 of 16
( )
)
φ
⎞
⎟ ⎟
⎠
Auxiliary ADC
The AUX_ADC register provides access to the auxiliary ADC
input channel. The ADC is a 12-bit successive approximation
converter, which has an equivalent input circuit to the one in
Figure 14. The maximum input range is +3.3 V. The ESD
protection diodes can handle 10 mA without causing
irreversible damage. The switch on-resistance (R1) has a typical
value of 100 Ω. The sampling capacitor, C2, has a typical value
of 16 pF.
CALIBRATION
Manual Bias Calibration
The bias offset registers in Table 10 and Table 11 provide a manual
adjustment function for the output of each sensor. For example,
if GYRO_OFF equals 0x1FF6, the GYRO_OUT offset shifts by
−10 LSBs, or −0.125°/sec. The DIN command for the upper
byte is DIN = 0x9B1F; for the lower byte, DIN = 0x9AF6.
Table 10. GYRO_OFF
Bits
[15:13]
[12:0]
Table 11. XACCL_OFF, YACCL_OFF, ZACCL_OFF
Bits
[15:12]
[11:0]
Gyroscope Automatic Bias Null Calibration
Set GLOB_CMD[0] = 1 (DIN = 0xBE01) to execute this function,
which measures GYRO_OUT and then loads GYRO_OFF with
the opposite value to provide a quick bias calibration. Then, all
sensor data resets to zero, and the flash memory updates
automatically (50 ms). See Table 12.
Gyroscope Precision Automatic Bias Null Calibration
Set GLOB_CMD[4] = 1 (DIN = 0xBE10) to execute this function,
which takes the sensor offline for 30 seconds while it collects a
set of GYRO_OUT data and calculates a more accurate bias
correction factor. Once calculated, the correction factor loads
into GYRO_OFF, all sensor data resets to zero, and the flash
memory updates automatically (50 ms). See Table 12.
Description
Not used.
Data bits. Twos complement, 0.0125°/sec per LSB.
Typical adjustment range = ±50°/sec.
Description
Not used.
Data bits, twos complement 0.6 mg/LSB.
Typical adjustment range = ±1.2 g.
Figure 14. Equivalent Analog Input Circuit
(Conversion Phase: Switch Open,
C1
Track Phase: Switch Closed)
VCC
D
D
R1
C2
ADIS16300