Evaluation Board User Guide
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
PL ATFORM BOARD
PC
USB
PORT
LOOP+
LOOP–
DIGITAL
ISOLATION
AD5421
EVAL-AD5421SDZ
09701-001
Figure 1.
