Preliminary Technical Data

AD5062/AD5063

Rev. Pr B | Page 15 of 17

reference. The AD5062/AD5063 have just one reference input,

REFIN. The voltage on the reference input is used to supply the

positive input to the Dac . Therefore any error in the reference

will be reflected in the Dac.

There are 4 possible sources of error when choosing a voltage

reference for high accuracy applications; initial accuracy, ppm

drift, long term drift and output voltage noise. Initial accuracy

on the output voltage of the Dac will lead to a full scale error in

the Dac. To minimize these errors, a reference with high initial

accuracy is preferred. Also, choosing a reference with an output

trim adjustment, such as the ADR425 allow a system designer

to trim system errors out by setting a reference voltage to a

voltage other than the nominal. The trim adjustment can also

be used at temperature to trim out any error.

AD5062/3

THREE-WIRE

SERIAL

INTERFACE

SYNC

SCLK

DIN

5V

4.096V

ADR392

Figure 29. ADR392 as Reference to AD5062/AD5063

Long term drift is a measure of how much the reference drifts

over time. A reference with a tight long term drift specification

ensures that the overall solution remains relatively stable

during its entire lifetime.

The temperature co-efficient of a references output voltage

affect INL,DNL TUE. A reference with a tight temperature co-

efficient specification should be chosen to reduce temperatue

dependence of the Dac output voltage on ambient conditions.

In high accuracy applications, which have a relatively low

noise budget, reference output voltage noise needs to be

considered. Choosing a reference with as low an output noise

voltage as practical for the system noise resolution required is

important. Precision voltage references such as the ADR435

produce low output noise in the 0.1-10Hz region. Examples of

some recommended precision references for use as supply to

the AD5060 are shown in the figure below..

Part list of precision references for use with

AD5062/AD5063.

Part No.

Initial

Accuracy

(mV max)

Temp Drift

(ppm

0.1-10Hz Noise

(uV p-p typ)

ADR435

+/-6

3

3.4

ADR425

+/-6

3

3.4

ADR02

+/-5

3

15

ADR395

+/-6

25

5

Bipolar Operation Using the AD5062/AD5063

The AD5062/AD5063 has been designed for single-supply

operation but a bipolar output range is also possible using the

circuit in Figure 30. The circuit below will give an output

voltage range of ±4.096 V. Rail-to-rail operation at the

amplifier output is achievable using an AD820 or an OP295 as

the output amplifier.

The output voltage for any input code can be calculated as

follows:

D

65536







×

R1 + R2

R1













R2

R1



































where

D represents the input code in decimal (0–16384).

With

VREF = 5 V, R1 = R2 = 10 kW:

10 × D

65536













5V

This is an output voltage range of ±5 V with 0000Hex

corresponding to a –5 V output and 3FFF Hex

corresponding to a +5 V output.

AD5063

DacGND

REF

OUT

SCLK

DIN

SYNC

+5V

+4.096V

EXTERNAL

OP AMP

BIPOLAR

OUTPUT

10u F

SERIAL

INTERFACE

0.1u F

0.1u F

INV

+5V

–5V

RFB

AGND

Figure 30. Bipolar Operation with the AD5063

Using AD5062/AD5063 with an Opto-Isolated

Interface Chip.

In process-control applications in industrial environments it is

often necessary to use an opto-isolated interface to protect and

isolate the controlling circuitry from any hazardous common-

mode voltages that may occur in the area where the DAC is

functioning. Because the AD5062/AD5063 uses a three-wire

serial logic interface, the ADuM130Xifamily s an ideal way to

provide digital isolation for the DAC interface.

The ADuM130x isolators provide three independent isolation

channels in a variety of channel configurations and data rates.

They operate across the full range from 2.7V to 5.5V, providing

compatibility with lower voltage systems as well as enabling a

voltage translation functionality across the isolation barrier.