Datasheet

TC520A
DS21431C-page 8 2001-2012 Microchip Technology Inc.
FIGURE 4-1: TC520 initialization & startup conversion timing relatioNships
FIGURE 4-2: lOad value modify cycle
4.4.6 OPTO-ISOLATED APPLICATIONS
The 3 wire serial port of the TC520A can be opto-
isolated for applications requiring isolated data acquisi-
tion. The additional control lines (LOAD, DV, READ)
are normally not needed in such applications, but can
also be brought across the isolation barrier with the
addition of a second isolator.
LOAD
LOAD VALUE updated
and conversion started
TC520A Conversion State
CE is pulled
high only during
AZ (DV = Low)
New LOAD VALUE
can be loaded
(if so desired)
TC520A held in
AZ phase
as lon
g
as CE = HIGH
CE
AZ INT
IZ
DINT
AZ INT INTDINT IZ
AZ AZ
D
IN
, D
CLK
DV
LOAD VALUE
shifted into
D
IN
Load
Value
LOAD
LOAD VALUE updated
and conversion started
TC520A Conversion State
CE
AZ INT
IZDINT AZ
INT
INT
DINT IZ
AZ
D
IN
, D
CLK
DV
LOAD VALUE
shift into
D
IN