Datasheet

LTC2378-18
16
237818f
TIMING DIAGRAMS
Normal Mode, Single Device
When CHAIN = 0, the LTC2378-18 operates in normal
mode. In normal mode, RDL/SDI enables or disables the
serial data output pin SDO. If RDL/SDI is high, SDO is in
high impedance. If RDL/SDI is low, SDO is driven.
Figure 13 shows a single LTC2378-18 operated in normal
mode with CHAIN and RDL/SDI tied to ground. With RDL/
SDI grounded, SDO is enabled and the MSB(D17) of the
new conversion data is available at the falling edge of
BUSY. This is the simplest way to operate the LTC2378-18.
CNV
LTC2378-18
BUSY
CONVERT
IRQ
DATA IN
DIGITAL HOST
CLK
SDO
SCK
237818 F13a
RDL/SDI
CHAIN
237818 F13
CONVERT CONVERT
t
ACQ
t
ACQ
= t
CYC
– t
CONV
– t
BUSYLH
POWER-DOWN AND ACQUIRE
POWER-DOWN
AND ACQUIRE
CNV
CHAIN = 0
BUSY
SCK
SDO
RDL/SDI = 0
t
BUSYLH
t
DSDOBUSYL
t
SCK
t
HSDO
t
SCKH
t
QUIET
t
SCKL
t
DSDO
t
CONV
t
CNVH
t
CYC
t
CNVL
D17 D16 D15 D1 D0
12 3 161718
Figure 13. Using a Single LTC2378-18 in Normal Mode