Datasheet

LTC2376-18
17
237618f
TIMING DIAGRAMS
Normal Mode, Multiple Devices
Figure 14 shows multiple LTC2376-18 devices operating
in normal mode (CHAIN = 0) sharing CNV, SCK and SDO.
By sharing CNV, SCK and SDO, the number of required
signals to operate multiple ADCs in parallel is reduced.
Since SDO is shared, the RDL/SDI input of each ADC must
be used to allow only one LTC2376-18 to drive SDO at a
time in order to avoid bus conflicts. As shown in Figure 14,
the RDL/SDI inputs idle high and are individually brought
low to read data out of each device between conversions.
When RDL/SDI is brought low, the MSB of the selected
device is output onto SDO.
237618 F14a
RDL
B
RDL
A
CONVERT
IRQ
DATA IN
DIGITAL HOST
CLK
CNV
LTC2376-18
SDO
A
SCK
RDL/SDI
CNV
LTC2376-18
SDO
B
SCK
RDL/SDI
CHAIN BUSY
CHAIN
237618 F14
D15
A
SDO
SCK
CNV
BUSY
CHAIN = 0
RDL/SDI
B
RDL/SDI
A
D15
B
D14
B
D1
B
D0
B
D13
B
D14
A
D13
A
D1
A
D0
A
Hi-Z
Hi-ZHi-Z
t
EN
t
HSDO
t
DSDO
t
DIS
t
SCKL
t
SCKH
t
CNVL
123 141516 171819303132
t
SCK
CONVERTCONVERT
t
QUIET
t
CONV
t
HOLD
t
BUSYLH
POWER-DOWN
ACQUIRE
ACQUIRE
POWER-DOWN
Figure 14. Normal Mode With Multiple Devices Sharing CNV, SCK and SDO