REV.0
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a
AD7398/AD7399
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 © Analog Devices, Inc., 2000
Quad, Serial-Input
12-Bit/10-Bit DACs
FUNCTIONAL BLOCK DIAGRAM
CLK
GND
V
DD
CS
SDI
DAC A
REGISTER
DAC A
INPUT
REG A
INPUT
REG B
INPUT
REG C
INPUT
REG D
SERIAL
REGISTER
POWER
ON RESET
DAC B
REGISTER
DAC C
REGISTER
DAC D
REGISTER
DAC D
DAC C
DAC B
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
V
REF
AV
REF
B
V
REF
CV
REF
D
LDACRS
V
SS
12/10
FEATURES
AD7398—12-Bit Resolution
AD7399—10-Bit Resolution
Programmable Power Shutdown
Single (3 V to 5 V) or Dual (H115505 V) Supply Operation
3-Wire Serial SPI-Compatible Interface
Internal Power ON Reset
Double Buffered Registers for Simultaneous
Multichannel DAC Update
Four Separate Rail-to-Rail Reference Inputs
Thin Profile TSSOP-16 Package Available
Low Tempco 1.5 ppm/H11543C
APPLICATIONS
Automotive Output Voltage Span
Portable Communications
Digitally Controlled Calibration
PC Peripherals
GENERAL DESCRIPTION
The AD7398/AD7399 family of quad, 12-bit/10-bit, voltage-
output digital-to-analog converters is designed to operate from a
single 3 V to 5 V or a dual ±5 V supply. Built with Analog’s robust
CBCMOS process, this monolithic DAC offers the user low
cost, and ease-of-use in single or dual-supply systems.
The applied external reference V
REF
determines the full-scale
output voltage. Valid V
REF
values include V
SS
< V
REF
< V
DD
that
result in a wide selection of full-scale outputs. For multiplying
applications ac inputs can be as large as ±5 V
P
.
A doubled-buffered serial-data interface offers high-speed,
3-wire, SPI and microcontroller-compatible inputs using serial-
data-in (SDI), clock (CLK), and a chip-select (CS). A common
level-sensitive load-DAC strobe (LDAC) input allows simulta-
neous update of all DAC outputs from previously loaded Input
Registers. Additionally, an internal power ON reset forces the
output voltage to zero at system turn ON. An external asynchro-
nous reset (RS) also forces all registers to the zero code state. A
programmable power-shutdown feature reduces power dissipa-
tion on unused DACs.
Both parts are offered in the same pinout to enable users to
select the appropriate resolution for their application without
redesigning the layout. For 8-bit resolution applications see the
pin compatible AD7304 product.
The AD7398/AD7399 is specified over the extended industrial
(–40°C to +125°C) temperature range. Parts are available in
wide body SOIC-16 and ultracompact thin 1.1 mm TSSOP-
16 packages.
CODE – Decimal
–0.50
0
512
DNL – LSB
0
–0.40
–0.30
–0.20
–0.10
0.10
0.20
0.30
0.40
0.50
1024 1536 2048 2560 3072 3584 4096
V
DD
= +5V
V
SS
= –5V
V
REF
= +2.5V
T
A
= 25H11543C
Figure 1. AD7398 DNL vs. Code (T
A
= 25°C)