LTC2378-16
TiMing DiagraMs
Normal Mode, Multiple Devices
Since SDO is shared, the RDL/SDꢁ input of each ADC must
be used to allow only one LTC2378-16 to drive SDO at a
timeinordertoavoidbusconflicts. AsshowninFigure14,
the RDL/SDꢁ inputs idle high and are individually brought
low to read data out of each device between conversions.
When RDL/SDꢁ is brought low, the MSꢀ of the selected
device is output onto SDO.
Figure 14 shows multiple LTC2378-16 devices operating
in normal mode (CHAꢁI = ±) sharing CIV, SCK and SDO.
ꢀy sharing CIV, SCK and SDO, the number of required
signals to operate multiple ADCs in parallel is reduced.
RDL
RDL
B
A
CONVERT
CNV
CNV
CHAIN
BUSY
SDO
IRQ
CHAIN
LTC2378-16
B
LTC2378-16
A
DIGITAL HOST
SDO
RDL/SDI
RDL/SDI
SCK
SCK
DATA IN
CLK
237816 F14a
POWER-DOWN
AND ACQUIRE
CONVERT
CONVERT
POWER-DOWN AND ACQUIRE
CHAIN = 0
t
CNVL
CNV
t
CONV
BUSY
t
BUSYLH
RDL/SDI
A
B
RDL/SDI
t
SCK
t
t
QUIET
SCKH
SCK
SDO
1
2
3
14
15
16
17
18
19
30
31
32
t
t
SCKL
HSDO
t
t
DIS
DSDO
t
EN
Hi-Z
Hi-Z
Hi-Z
D15
D14
D13
D1
A
D0
A
D15
D14
D13
D1
B
D0
B
A
A
A
B
B
B
237816 F14
Figure 140 Normal Mode With Multiple Devices Sharing CNV, SCK and SDO
237816f
17
LINEAR_DIMENSIONS [ Linear Dimensions ]
