FUNCTIONAL BLOCK DIAGRAM

D

A

C

A

R

E

G

I

S

T

E

R

D

PR

En

S

H

I

F

T

R

E

G

I

S

T

E

R

D

A

C

B

R

E

G

I

S

T

E

R

D

PR

R

E

F

E

R

E

N

C

E

B

A

N

D

G

A

P

DAC A

DAC B

REF

BUF

REF

BUF

AD8303

CS

CLK

SDI

(DATA)

LDA

LDB

DGND

MSB

RS

AGND

SHDN

OP

AMP

A

OP

AMP

B

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.

a

+3 V, Dual, Serial Input

Complete 12-Bit DAC

AD8303

© Analog Devices, Inc., 1996

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

FEATURES

Complete Dual 12-Bit DAC

Pretrimmed Internal Voltage Reference

Single +3 V Operation

0.5 mV/Bit with 2.0475 V Full Scale

Low Power: 9.6 mW

3-Wire Serial SPI Compatible Interface

A

Compact SO-14, 1.75 mm Height Package

APPLICATIONS

Portable Communications

Digitally Controlled Calibration

Servo Controls

PC Peripherals

GENERAL DESCRIPTION

The AD8303 is a complete (includes internal reference) dual,

12-bit, voltage output digital-to-analog converter designed to

operate from a single +3 volt supply. Built using a CBCMOS

process, this monolithic DAC offers the user low cost and ease-

of-use in single-supply +3 volt systems. Operation is guaranteed

over the supply voltage range of +2.7 V to +5.5 V making this

device ideal for battery operated applications.

The 2.0475 V full-scale voltage output is laser-trimmed to

maintain accuracy over the operating temperature range of the

device. The binary input data format provides an easy-to-use

one-half millivolt-per-bit software programmability. The voltage

outputs are capable of sourcing 3 mA.

DIGITAL INPUT CODE – Decimal

1.0

–1.0

0

4096

1024

2048

3072

0.8

0.2

0

–0.4

–0.8

0.6

0.4

–0.2

–0.6

Figure 1. Differential Nonlinearity Error vs. Code

A double buffered serial data interface offers high speed, three-

wire, DSP and SPI microcontroller compatible inputs using

data in (SDI), clock (CLK) and load strobe (LDA + LDB)

pins. A chip-select (CS) pin simplifies connection of multiple

DAC packages by enabling the clock input when active low.

Additionally, an RS input sets the output to zero scale or to 1/2

scale based on the level applied to the MSB pin. A power

shutdown feature reduces power dissipation to less than 3

µW.

The AD8303 is specified over the extended industrial (–40

°C to

+85

°C) temperature range. AD8303s are available in plastic

DIP and low profile 1.75 mm height SO-14 surface mount

packages. For single-channel DAC applications, see the

AD8300 which is offered in the 8-lead DIP and SO-8 packages.

DIGITAL INPUT CODE – Decimal

2

–2

1.5

0

–0.5

–1

–1.5

1

0.5

0

1024

2048

3072

4096

+25

°C

+85

°C

–40

°C

Figure 2. Linearity Error vs. Digital Code and Temperature