Datasheet

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SBAS325B − JUNE 2004 − REVISED APRIL 2009
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22
SPECIAL CONSIDERATIONS
Cascading Multiple Converters
Multiple DDC118 units can be connected in serial
configuration, as illustrated in Figure 21.
DOUT can be used with DIN to daisy-chain several
DDC118 devices together to minimize wiring. In this mode
of operation, the serial data output is shifted through
multiple DDC118s, as illustrated in Figure 21.
See Figure 22 for the timing diagram when the DIN input
is used to daisy-chain several devices. Table 11 gives the
timing specification for data retrieval using DIN.
IN8
ASensor
DIN
DIN
DOUT
DOUT
DDC118
DIN
DIN
DOUT
DOUT
DIN
DIN
DOUT
DOUT
DVALID
DCLK DCLK
Data Retrieval
Outputs
IN7
B
IN6
C
IN5
D
IN4
E
IN3
F
IN2
G
IN1
H
IN8
I
IN7
J
IN6
K
IN5
L
IN4
M
IN3
N
IN2
O
IN1
P
IN8
Q
IN7
R
IN6
S
IN5
T
IN4
U
IN3
V
IN2
W
IN1
X
DVALID
DCLK DCLK
DVALID
DCLK DCLK
DDC118 DDC118
Data Clock
Figure 21. Daisy-Chained DDC118s
CLK
DVALID
DCLK
DIN
t
18
t
19
t
21
t
20
t
20
t
22
t
23
DOUT
Input A
MSB
Input A
LSB
Input B
MSB
Input L
LSB
Input M
MSB
Input W
LSB
Input X
MSB
Input X
LSB
Input A
MSB
Figure 22. Timing Diagram When Using the DIN Function of the DDC118
Table 11. Timing for the DDC118 Data Retrieval Using DIN
SYMBOL DESCRIPTION MIN TYP MAX UNITS
t
22
Set-Up Time From DIN to Falling Edge of DCLK 5 ns
t
23
Hold Time For DIN After Falling Edge of DCLK 4 ns