Datasheet

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SBAS255C − JUNE 2004 − REVISED APRIL 2009
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22
SPECIAL CONSIDERATIONS
Cascading Multiple Converters
Multiple DDC114 units can be connected in serial
configuration, as illustrated in Figure 21.
DOUT can be used with DIN to daisy-chain several
DDC114 devices together to minimize wiring. In this mode
of operation, the serial data output is shifted through
multiple DDC114s, 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.
IN4 IN3 IN2 IN1
ASensor BCD
DIN
DIN
DOUT
DOUT
DDC114
DIN
DIN
DOUT
DOUT
DIN
DIN
DOUT
DOUT
DVALID
DCLK DCLK
Data Retrievel
Outputs
DVALID
DCLK DCLK
DVALID
DCLK DCLK
IN4 IN3 IN2 IN1
EFGH
DDC114
IN4 IN3 IN2 IN1
IJKL
DDC114
Data Clock
Figure 21. Daisy-Chained DDC114s
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 F
LSB
Input G
MSB
Input K
LSB
Input L
MSB
Input L
LSB
Input A
MSB
Figure 22. Timing Diagram When Using the DIN Function of the DDC114
Table 11. Timing for the DDC114 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