ADIS16251 Analog Devices, ADIS16251 Datasheet - Page 16

• Manufacturer Part Number: ADIS16251
• Description: Programmable Low Power Gyroscope
• Manufacturer: Analog Devices

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DataSheet
ADIS16251
Dynamic Range
The ADIS16251 provides three dynamic range settings: ±80°/sec,
±40°/sec, and ±20°/sec. The lower dynamic range settings
(20, 40) limit the minimum filter tap sizes in order to maintain
the resolution as the maximum rate measurements decrease.
The recommended order for programming the SENS/AVG
register is (1) dynamic range and then (2) filtering response.
The contents of the SENS/AVG register are nonvolatile.
Table 19. SENS/AVG Register Definition
Address
0x39, 0x38
Table 20. SENS/AVG Bit Description
Bit
15:11
10:8
7:4
3:0
Auxiliary DAC
The auxiliary DAC provides a 12-bit level adjustment function.
The AUX_DAC register controls the operation of this feature. It
offers a rail-to-rail buffered output that has a range of 0 V to 2.5 V.
The DAC can drive its output to within 5 mV of the ground
reference when it is not sinking current. As the output
approaches ground, the linearity begins to degrade (100 LSB
beginning point). As the sink current increases, the nonlinear
range increases. The DAC output latch function, contained in
the COMMAND register, provides continuous operation while
writing each byte of this register. The contents of this register
are volatile, which means that the desired output level must be
set after every reset and power cycle event.
Table 21. AUX_DAC Register Definition
Address
0x31, 0x30
Table 22. AUX_DAC Bit Descriptions
Bit
15:12
11:0
4
U
Value
100
010
001
.com
Default
0x0402
Description
Not used
Sensitivity selection bits
80°/sec (default condition)
40°/sec, filter taps ≥ 4 (bit 3:0 ≥ 0x02)
20°/sec, filter taps ≥16 (bit 3:0 ≥ 0x04)
Not used
Filter tap setting, M = binary number
(number of taps, N = 2
Default
0x0000
Description
Not used
Data bits
Format
Binary
Format
Binary
M
)
Access
R/W
Access
R/W
Rev. PrA | Page 16 of 20
General Purpose I/O
The ADIS16251 provides two general-purpose pins that enable
digital I/O control using the SPI. The GPIO_CTRL control
register establishes the configuration of these pins and handles
the SPI-to-pin controls. Each pin provides the flexibility of both
input (read) and output (write) operations. For example, writing
a 0x0202 to this register establishes Line 0 as an output and set
its level as a one. Writing 0x0000 to this register establishes both
lines as inputs, and their status can be read through Bit 0 and Bit 1
of this register.
The digital I/O lines are also available for data ready and
alarm/error indications. In the event of conflict, the following
priority structure governs the digital I/O configuration:
Table 23. GPIO_CTRL Register Definition
Address
0x33, 0x32
Table 24. GPIO_CTRL Bit Descriptions
Bit
15:10
9
8
7:2
1
0
STATUS AND DIAGNOSTICS
The ADIS16251 provides a number of status and diagnostic
functions. Table 25 provides a summary of these functions,
along with their appropriate control registers.
Table 25. Status and Diagnostic Functions
Function
Data ready I/O indicator
Self test, mechanical check for MEMS sensor
Status
Flash memory endurance
Alarms
Check for predefined output conditions
Configure and check for user-specific
conditions
1.
2.
3.
Description
Not used
General purpose I/O line 0, data direction control
General purpose I/O line 1, data direction control
Not used
General purpose I/O line 0 polarity
General purpose I/O line 1 polarity
GPIO_CTRL
MSC_CTRL
ALM_CTRL
1 = output, 0 = input
1 = output, 0 = input
1 = high, 0 = low
1 = high, 0 = low
Default
0x0000
Preliminary Technical Data
Format
N/A
Register
MSC_CTRL
MSC_CTRL
STATUS
ENDURANCE
ALM_MAG1/2
ALM_SMPL1/2
ALM_CTRL
Access
R/W