a
+5 Volt, Serial Input,
Dual 12-Bit DAC
AD8522
FEATURES
Complete Dual 12-Bit DAC
No External Components
+5 V Single-Supply Operation ؎10%
4.095 V Full Scale (1 mV/LSB)
Buffered Voltage Outputs
Low Power: 5 mW/DAC
Space Saving 1.5 mm Height SO-14 Package
APPLICATIONS
Digitally Controlled Calibration
Servo Controls
Process Control Equipment
Computer Peripherals
Portable Instrumentation
Cellular Base Stations Voltage Adjustment
FUNCTIONAL BLOCK DIAGRAM
VDD
CS
CLK
CLK
LATCH
DAC A
REGISTER
The AD8522 is a complete dual 12-bit, single-supply, voltage
output DAC in a 14-pin DIP, or SO-14 surface mount package.
Fabricated in a CBCMOS process, features include a serial digital interface, onboard reference, and buffered voltage output.
Ideal for +5 V-only systems, this monolithic device offers low
cost and ease of use, and requires no external components to
realize the full performance of the device.
The serial digital interface allows interfacing directly to numerous microcontroller ports, with a simple high speed, three-wire
data, clock, and load strobe format. The 16-bit serial word contains the 12-bit data word and DAC select address, which is decoded internally or can be decoded externally using LDA, LDB
0.6
LINEARITY ERROR – LSB
VOUTA
SHIFT
REGISTER
12
BANDGAP
REFERENCE
REF
BUF
VREF
REF
BUF
D
DAC B
REGISTER
SDO
12
LDA
LDB
DAC B
CONTROL
LOGIC
OP
AMP
B
VOUTB
AD8522
MSB RS
AGND
inputs. A serial data output allows the user to easily daisy-chain
multiple devices in conjunction with a chip select input. A reset
RS input sets the outputs to zero scale or midscale, as determined by the input MSB.
The output 4.095 V full scale is laser trimmed to maintain accuracy over the operating temperature range of the device, and
gives the user an easy-to-use one-millivolt-per-bit resolution. A
2.5 V reference output is also available externally for other data
acquisition circuitry, and for ratiometric applications. The output buffers are capable of driving ± 5 mA.
The AD8522 is available in the 14-pin plastic DIP and low profile 1.5 mm SOIC-14 packages.
PACKAGE TYPES AVAILABLE
VDD = +4.5V
TA = –55°C, +25°C, +85°C, +125°C
0.4
OP
AMP
A
D
SDI
(DATA)
DGND
GENERAL DESCRIPTION
DAC A
12
+25°C
0.2
–55°C
0
–0.2
–0.4
PDIP-14
+85°C
–0.6
SO-14
+125°C
–0.8
–1.0
0
1024
2048
3072
DIGITAL INPUT CODE – Decimal
4096
Figure 1. Linearity Error vs. Digital Code & Temperature
REV. A
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
