Evaluation Board User Guide

UG-250

One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com

Evaluation Board for 16-Bit, Serial Input, Loop-Powered 4 mA to 20 mA DAC

PLEASE SEE THE LAST PAGE FOR AN IMPORTANT

WARNING AND LEGAL TERMS AND CONDITIONS.

Rev. A | Page 1 of 12

FEATURES

Full-featured evaluation board for the AD5421

Link options

PC control in conjunction with Analog Devices, Inc.,

system demonstration platform (SDP)

PC software for control

EQUIPMENT NEEDED

DC power supply unit

SDP for PC control (EVAL-SDP-CB1Z)

Voltmeter or ammeter

DOCUMENTS NEEDED

AD5421 data sheet

SOFTWARE NEEDED

AD5421 evaluation software

EVALUATION BOARD DESCRIPTION

The EVAL-AD5421 is a full-featured evaluation board, designed

to allow the user to easily evaluate all features of the AD5421

loop-powered 4 mA to 20 mA DAC. The AD5421 pins are

accessible at on-board connectors for external connection. The

AD5421 evaluation board is controlled via the PC’s USB port in

conjunction with Analog Device’s system demonstration

platform board. The SDP board allows the evaluation board to

be controlled through the USB port of a Windows® XP (SP2 or

later) or Vista-based (32-bit) PC using the AD5421 evaluation

software. The AD5421 serial interface is also accessible at the

testpoint connections on the board.

DEVICE DESCRIPTION

The AD5421 is an integrated device designed for use in loop-

powered 4 mA to 20 mA smart transmitter applications. The

AD5421, in a single chip, provides a 16-bit DAC and current

amplifier for digital control of the loop current, a voltage

regulator to power the entire transmitter, a voltage reference,

fault alert functions, flexible SPI-compatible serial interface,

gain and offset adjust registers as well as other features and

functions.

Complete specifications for the AD5421 are available in the

AD5421 data sheet available from Analog Devices and should

be consulted in conjunction with this document when using the

evaluation board.

FUNCTIONAL BLOCK DIAGRAM

SYSTEM DEMONSTRATION

PLATFORM BOARD

PC

USB

PORT

LOOP+

LOOP–

DIGITAL

ISOLATION

AD5421

EVAL-AD5421SDZ

Figure 1.