Datasheet

LTC2364-18
15
236418f
TIMING DIAGRAMS
The serial interface on the LTC2364-18 is simple and
straightforward to use. The following sections describe the
operation of the LTC2364-18. Several modes are provided
depending on whether a single or multiple ADCs share the
SPI bus or are daisy chained.
Normal Mode, Single Device
When CHAIN = 0, the LTC2364-18 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 10 shows a single LTC2364-18 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 LTC2364-18.
Figure 10. Using a Single LTC2364-18 in Normal Mode
CNV
LTC2364-18
BUSY
CONVERT
IRQ
DATA IN
DIGITAL HOST
CLK
SDO
SCK
RDL/SDI
CHAIN
236418 F10
CONVERT CONVERT
t
ACQ
t
ACQ
= t
CYC
– t
HOLD
POWER-DOWNPOWER-DOWN
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
HOLD
ACQUIRE
t
CYC
t
CNVL
D17 D16 D15 D1 D0
1 2 3 16 17 18
ACQUIRE