ADIS16100 Analog Devices, Inc., ADIS16100 Datasheet - Page 12

• Manufacturer Part Number: ADIS16100
• Description: ?300?/sec Yaw Rate Gyroscope With Spi
• Manufacturer: Analog Devices, Inc.

ADIS16100
BASIC OPERATION
The ADIS16100 is designed for simple integration into indus-
trial system designs, requiring only a 5.0 V power supply and a
4-wire, industry standard serial peripheral interface (SPI). The SPI
handles all digital I/O communication in the ADIS16100.
SERIAL PERIPHERAL INTERFACE (SPI)
The ADIS16100 SPI port includes four signals: chip select ( CS ),
serial clock (SCLK), data input (DIN), and data output
(DOUT). The CS line enables the ADIS16100 SPI port and
frames each SPI event. When this signal is high, the DOUT
lines are in a high impedance state and the signals on DIN and
SCLK have no impact on operation. A complete data frame
contains 16 clock cycles. Because the SPI port operates in full
duplex mode, it supports simultaneous, 16-bit receive (DIN) and
transmit (DOUT) functions within the same data frame.
Control Register
The DIN control register provides controls for two operational
settings: the output data source and the coding (twos comple-
ment vs. offset binary). Table 5 and Figure 22 provide the
proper bit definitions for control register configuration. The
DIN sequence starts with a 1 for configuration sequences and a
0 for read sequences. When this bit is 0, the remaining DIN bits
do not change the control register and the next sample’s output
data reflects the existing configuration. Data loads from
the DIN pin into the ADIS16100 on the falling edge of SCLK.
Once the 16-SCLK sequence is complete, the control register is
updated and ready for the next read sequence. If a data frame
has less than 16 SCLK cycles, the control register does not
update and maintains its previous configuration. The DIN bit
definitions in Table 5, which have either 0 or 1 assigned to
them, are critical for proper operation.
DOUT
SCLK
DOUT
SCLK
DIN
CS
DIN
CS
WRITE
0
1
CONFIGURATION COMMAND FOR NEXT OUTPUT SEQUENCE
0
ADC PLACED IN HOLD MODE
0
DATA OUTPUT, BASED ON PREVIOUS CONFIGURATION
2
ADD1
D/C
DATA FRAME
3
ADD0
D/C
4
Figure 22. SPI Sequence, Clock Polarity = 1, Clock Phase = 0
D11
ADD1
Figure 21. Configuration and Read Sequence
5
D10
ADD0
6
D9
Rev. B | Page 12 of 16
1
7
D8
1
8
D7
D/C
ADC Conversion
The chip select ( CS ) and serial clock (SCLK) lines control the
on-board analog-to-digital conversion process. When the chip
select line goes low, the DOUT line comes out of three-state
mode, the track-and-hold goes into hold mode, and the ADC
samples the analog input at this point. The track-and-hold
returns to track mode on the 14
The serial clock drives the internal ADC conversion clock,
using its falling edge for control of this process. All 16 SCLK
cycles are required for a complete conversion. If a data frame
has less than 16 SCLK cycles, the conversion cannot complete
and does not update the output data for the next data frame cycle.
Output Data Access
The DOUT sequence starts with two zeros, one that clocks out
after the falling edge of CS , and a second one that clocks out on
the first SCLK falling edge. The next 14 bits, ADD0, ADD1 and
the 12 data bits, clock out on SCLK falling edges. After the 16
falling edge, the DOUT line moves to a three-state mode.
When setting up the system process to receive data from the
ADIS16100, use a clock phase setting of 0 and a clock polarity
setting of 1. These settings reflect the timing displayed in
Figure 22. To maintain proper communication at the maximum
specified clock rates, the system processor must be able to
support the setup time requirement, listed in Figure 2 and
Table 2 (t
ADC PLACED IN TRACK MODE
9
D6
D/C
10
9
).
NEXT COMMAND, IF NECESSARY
D5
0
11
D4
CODE
DATA FRAME
12
D3
D/C
13
D2
D/C
th
14
falling edge of the SCLK line.
D1
D/C
15
D0
D/C
16
th