EVAL-AD5142DBZ View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
EVAL-AD5142DBZ
Analog Devices
'EVAL-AD5142DBZ' PDF : 32 Pages View PDF
Data Sheet
AD5122/AD5142
Daisy-Chain Connection
Daisy chaining minimizes the number of port pins required from
the controlling IC. As shown in Figure 40, the SDO pin of one
package must be tied to the SDI pin of the next package. The clock
period can be increased because of the propagation delay of the
line between subsequent devices. When two AD5122/AD5142
devices are daisy chained, 32 bits of data are required. The first
16 bits assigned to U2, and the second 16 bits assigned to U1, as
shown in Figure 41. Keep the SYNC pin low until all 32 bits are
clocked into their respective serial registers. The SYNC pin is
then pulled high to complete the operation. A typical connection is
shown in Figure 40.
To prevent data from mislocking (for example, due to noise) the
device includes an internal counter, if the clock falling edges
count is not a multiple of 8, the device ignores the command. A
valid clock count is 16, 24, or 32. The counter resets
when SYNC returns high.
MOSI
MICROCONTROLLER
MISO SCLK SS
VLOGIC
AD5122/
AD5142
SDI U1 SDO
RP
2.2kΩ
VLOGIC
AD5122/
AD5142
SDI U2 SDO
RP
2.2kΩ
SYNC SCLK
SYNC SCLK
SCLK
SYNC
MOSI
SDO_U1
Figure 40. Daisy-Chain Configuration
1
2
16
17
18
32
DB15
DB15
DB0 DB15
DB0
INPUT WORD FOR U2
INPUT WORD FOR U1
DB0 DB15
DB0
UNDEFINED
INPUT WORD FOR U2
Figure 41. Daisy-Chain Diagram
Rev. C | Page 21 of 32
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