a
FEATURES
Fast, Flexible, Microprocessor Interfacing in Serially
Controlled Systems
Buffered Digital Output Pin for Daisy-Chaining
Multiple DACs
Minimizes Address-Decoding in Multiple DAC
Systems鈥擳hree-Wire Interface for Any Number of DACs
One Data Line
One CLK Line
One Load Line
Improved Resistance to ESD
鈥?0 C to +85 C for the Extended Industrial Temperature
Range
APPLICATIONS
Multiple-Channel Data Acquisition Systems
Process Control and Industrial Automation
Test Equipment
Remote Microprocessor-Controlled Systems
GENERAL INFORMATION
12-Bit Serial Daisy-Chain
CMOS D/A Converter
DAC8143
FUNCTIONAL BLOCK DIAGRAM
V
DD
R
FB
DAC8143
V
REF
12-BIT
D/A CONVERTER
I
OUT1
I
OUT2
CLR
LD
1
LD
2
STB
1
STB
4
STB
3
STB
2
SRI
IN
CLK
INPUT 12-BIT
SHIFT REGISTER
OUT
SRO
AGND
DAC REGISTER
LOAD
DGND
The DAC8143 is a 12-bit serial-input daisy-chain CMOS D/A
converter that features serial data input and buffered serial data
output. It was designed for multiple serial DAC systems, where
serially daisy-chaining one DAC after another is greatly simplified.
The DAC8143 also minimizes address decoding lines enabling
simpler logic interfacing. It allows three-wire interface for any
number of DACs: one data line, one CLK line and one load line.
Serial data in the input register (MSB first) is sequentially
clocked out to the SRO pin as the new data word (MSB first) is
simultaneously clocked in from the SRI pin. The strobe inputs
are used to clock in/out data on the rising or falling (user
selected) strobe edges (STB
1
, STB
2
,
STB3,
STB
4
).
When the shift register鈥檚 data has been updated, the new data
word is transferred to the DAC register with use of
LD1
and
LD2
inputs.
Separate LOAD control inputs allow simultaneous output up-
dating of multiple DACs. An asynchronous CLEAR input
resets the DAC register without altering data in the input
register.
Improved linearity and gain error performance permits reduced
circuit parts count through the elimination of trimming compo-
nents. Fast interface timing reduces timing design considerations
while minimizing microprocessor wait states.
The DAC8143 is available in plastic packages that are compat-
ible with autoinsertion equipment.
Plastic packaged devices come in the extended industrial tem-
perature range of 鈥?0掳C to +85掳C.
REV. C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
漏 Analog Devices, Inc., 1999
WR
ADDRESS BUS
ADDRESS
DECODER
DB
X
SRI
STROBE
SRO LOAD
P
SRI
DAC8143
STROBE
SRO LOAD
DAC8143
SRI
STROBE
SRO LOAD
DAC8143
SRI
STROBE
SRO LOAD
DAC8143
Figure 1. Multiple DAC8143s with Three-Wire Interface
1
2
3
4
5
6
7
8
9
10
11
12
