a
FEATURES
Complete Dual 12-Bit DAC
No External Components
Single +5 Volt Operation
1 mV/Bit with 4.095 V Full Scale
True Voltage Output,
±5
mA Drive
Very Low Power: 5 mW
APPLICATIONS
Digitally Controlled Calibration
Portable Equipment
Servo Controls
Process Control Equipment
PC Peripherals
LDA
CS
A/B
DATA
+5 Volt, Parallel Input
Complete Dual 12-Bit DAC
AD8582
FUNCTIONAL BLOCK DIAGRAM
AD8582
DAC A
REGISTER
INPUT A
REGISTER
12
2
INPUT B
REGISTER
12
REFERENCE
V
REF
12
V
DD
12-BIT
DAC A
V
OUTA
LDB
DAC B
REGISTER
12-BIT
DAC B
V
OUTB
AGND
DGND
RST MSB
GENERAL DESCRIPTION
The AD8582 is a complete, parallel input, dual 12-bit, voltage
output DAC designed to operate from a single +5 volt supply.
Built using a CBCMOS process, this monolithic DAC offers the
user low cost, and ease-of-use in +5 volt only systems.
Included on the chip, in addition to the DACs, are a rail-to-rail
amplifier, latch and reference. The reference (V
REF
) is trimmed
to 2.5 volts output, and the on-chip amplifier gains up the DAC
output to 4.095 volts full scale. The user needs only supply a +5
volt supply.
The AD8582 is coded natural binary. The op amp output
swings from 0 volt to +4.095 volts for a one-millivolt-per-bit
resolution, and is capable of driving
±
5 mA. Operation down to
4.3 V is possible with output load currents less than 1 mA.
5.0
∆∆VFS
≤
1 LSB
DATA = FFF
H
T
A
= +25
°
C
The high speed parallel data interface connects to the fastest
processors without wait states. The double-buffered input struc-
ture allows the user to load the input registers one at a time,
then a single load strobe tied to both LDA + LDB inputs will
update both DAC outputs simultaneously. LDA and LDB can
also be activated independently to immediately update their re-
spective DAC registers. An address input decodes DAC A or
DAC B when the chip select
CS
input is strobed. An asynchro-
nous reset input sets the output to zero scale. The MSB bit can
be used to establish a preset to midscale when the reset input is
strobed.
The AD8582 is available in the 24-pin plastic DIP and the sur-
face mount SOIC-24. Each part is fully specified for operation
over –40°C to +85°C, and the full +5 V
±
5% power supply
range.
2.0
1.5
V
DD
= +5V
T = –55°C, +25°C, +85°C
A
4.8
LINEARITY ERROR – LSB
V
DD
MIN – Volts
1.0
0.5
0.0
–0.5
–1.0
–1.5
4.6
PROPER OPERATION
WHEN V
DD
SUPPLY
VOLTAGE ABOVE
CURVE
4.4
4.2
= +25°C & +85°C
= –55°C
4.0
0.01
0.1
1.0
10
OUTPUT LOAD CURRENT – mA
100
–2.0
0
1024
2048
3072
4096
DIGITAL INPUT CODE – Decimal
Figure 1. Minimum Supply Voltage vs. Load
Figure 2. Linearity Error vs. Digital Code and Temperature
REV. 0
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: 617/329-4700
Fax: 617/326-8703
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