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FUNCTIONAL BLOCK DIAGRAM

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.

+5 Volt, Serial Input,

Dual 12-Bit DAC

12

CS

CLK

SDI

(DATA)

SDO

12

12

LDA

LDB

DGND

MSB RS

AGND

D

REF

BUF

BANDGAP

REFERENCE

OP

AMP

A

DAC A

OP

AMP

B

AD8522

DAC A

REGISTER

D

DAC B

REGISTER

CONTROL

LOGIC

CLK

LATCH

REF

BUF

DAC B

SHIFT

REGISTER

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 deter-

mined by the input MSB.

The output 4.095 V full scale is laser trimmed to maintain accu-

racy 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 out-

put buffers are capable of driving

±5 mA.

The AD8522 is available in the 14-pin plastic DIP and low pro-

file 1.5 mm SOIC-14 packages.

GENERAL DESCRIPTION

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 digi-

tal 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 numer-

ous microcontroller ports, with a simple high speed, three-wire

data, clock, and load strobe format. The 16-bit serial word con-

tains the 12-bit data word and DAC select address, which is de-

coded internally or can be decoded externally using LDA, LDB

0.6

0.4

0.2

0

–1.0

–0.6

–0.8

–0.2

–0.4

4096

0

3072

1024

2048

DIGITAL INPUT CODE – Decimal

+85

°C

+125

°C

+25

°C

–55

°C

PACKAGE TYPES AVAILABLE

AD8522

a

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

Figure 1. Linearity Error vs. Digital Code & Temperature

PDIP-14

SO-14