Datasheet UG-250 Datasheet (ANALOG DEVICES)

Evaluation Board User Guide

UG-250

SYSTEM DEMONSTRATION

PLATFORM BOARD

PC

USB

PORT

LOOP+

LOOP–

DIGITAL

ISOLATION

AD5421

EVAL-AD5421SDZ

09701-001

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

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

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 loop­powered 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.

PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITI ONS.

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

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UG-250 Evaluation Board User Guide

TABLE OF CONTENTS

Features .............................................................................................. 1

Equipment Needed ........................................................................... 1

Documents Needed .......................................................................... 1

Software Needed ............................................................................... 1

Evaluation Board Description ......................................................... 1

Device Description ........................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Evaluation Board Hardware ............................................................ 3

REVISION HISTORY

10/11—Rev. 0 to Rev. A

Change to Figure 4 ........................................................................... 7

3/11—Revision 0: Initial Version

Power Supplies ...............................................................................3

Link Options ..................................................................................3

Evaluation Board Software Quick Start Procedures .....................5

Software Installation .....................................................................5

Software Operation .......................................................................5

Main Window ................................................................................6

Evaluation Board Schematics and Artwork ...................................7

Ordering Information .................................................................... 11

Bill of Materials ........................................................................... 11

Rev. A | Page 2 of 12

Evaluation Board User Guide UG-250

LK7

Inserted

EVALUATION BOARD HARDWARE

POWER SUPPLIES

The AD5421 evaluation board requires one power supply
connection from LOOP− to LOOP+ (J7), a voltage in the
range from 5.5 V to 52 V can be applied if the on-board
MOSFET device (U2) is not enabled. With U2 enabled, the
voltage limit is the breakdown voltage of U2, which in this
case is 240 V. A load resistor can also be connected at J7.

LINK OPTIONS

Set the link options on the evaluation board for the required
operating setup before powering on the board. The functions
of the link options are described in Table 2.

Default Link Option Setup

The default link options are listed in Tabl e 1.

Table 1. Link Options

Link No. Option

LK1 Inserted
LK2 B
LK4 Inserted
LK6 Inserted

Alarm_Dir B
Rint_Rext B
Range0 B
Range1 B
Reg_Sel0 A
Reg_Sel1 B
Reg_Sel2 A

Rev. A | Page 3 of 12

UG-250 Evaluation Board User Guide

B A B

3 V

A B A

9 V

Table 2. Link Options

Link No. Description

LK1 This link connects the V

When this link is inserted, the V
When this link is removed, the V

LK2 This link enables/disables the MOSFET device.

Position A disables the MOSFET device.
Position B enables the MOSFET device and the loop supply is connected directly to the REG

LK4

This link enables/disables the iCoupler® digital isolators.
When this link is inserted, the isolators are enabled.
When this link is removed, the isolators are disabled.

LK6 This link should be inserted when the MOSFET device is enabled (LK2 in Position B).

This link should be removed when the MOSFET device is disabled (LK2 in Position A).

LK7 This link completes the loop connection if a load resistor is not connected at Connector J7.

This link should be inserted if a load resistor is not connected at Connector J7.
This link should be removed if a load resistor is connected at Connector J7.

Alarm_Dir This link selects the alarm current direction.

Position A selects an upscale alarm current (22.8 mA or 24 mA).
Position B selects a downscale alarm current (3.2 mA).

Rint_Rext This link selects to use either the internal or external current setting resistor.

Position A selects the internal resistor.
Position B selects the external resistor.

Range0,
Range1

These links select the loop current range.

Range1 Range0 Loop Range

B B 4 mA to 20 mA
B A 3.8 mA to 21 mA
A B 3.2 mA to 24 mA
A A 3.8 mA to 21 mA

Reg_Sel2,
Reg_Sel1,
Reg_Sel0

These links select the voltage regulator output voltage.

Reg_Sel2 Reg_Sel1 Reg_Sel0 Regulator Output Voltage

B B B 1.8 V
B B A 2.5 V

input pin to the LOOP+ voltage via a 20:1 resistor divider.

LOOP

pin is connected to the resistor divider.

LOOP

pin is unconnected and can be connected to another voltage (maximum 2.5 V) via TP26.

LOOP

pin.

IN

B A A 3.3 V
A B B 5 V

A A B 12 V

Rev. A | Page 4 of 12

Evaluation Board User Guide UG-250

09701-002

EVALUATION BOARD SOFTWARE QUICK START PROCEDURES

SOFTWARE INSTALLATION

The AD5421 evaluation kit includes self-installing software on
a CD. The software is compatible with Windows XP (SP2) and
Vista (32-bit). If the setup file does not run automatically, you
can run setup.exe from the CD.

Install the evaluation software before connecting the evaluation
board and SDP board to the USB port of the PC to ensure that
the evaluation system is correctly recognized when connected
to the PC.

1. After installation from the CD is complete, power up the

AD5421 evaluation board as described in the Power
Supplies section.

2. Connect the SDP board to the AD5421 evaluation board

and then to the USB port of your PC using the supplied
cable. Either connector of the SDP board may be used.

3. When the evaluation system is detected, proceed through

any dialog boxes that appear. This finishes the installation.

SOFTWARE OPERATION

To launch the software, complete the following steps:

1. From the Start menu, select Analog Devices – AD5421;

then select AD5421 Evaluation Software. The main
window of the software displays (see Figure 3).

2. If the evaluation system is not connected to the USB port

when the software is launched, or if the AD5421 board is
not connected to the SDP board, a connectivity error
displays (see Figure 2). Simply connect the evaluation
board to the USB port of the PC, wait a number of seconds,
click Rescan, and follow the instructions.

Figure 2. Connectivity Error Alert

Rev. A | Page 5 of 12

UG-250 Evaluation Board User Guide

09701-003

Figure 3. Main Window

MAIN WINDOW

As can be seen in Figure 3, the main window is made up of
5 tabs; Control Register, DAC Register, Fault Register,
Program Loop Current, and C omm a n d Wr i t e. Outside
of the tab structure at the top right of the window are two
control items; L DAC PIN to set the state of the LDAC pin
and USE PEC to select whether packet error checking is used
in the communications with the AD5421. There is also an
indicator item; PEC Error, this alerts to a packet error in the
data received from the AD5421. At the bottom of the window
is a display of the contents of the fault register, this is updated
on every communication with the AD5421 if Auto Fault
Readback is enabled.

Control Register

The Control Register tab is displayed by default. This tab
allows the user to program the control register.

DAC Register

The DAC Register tab allows the user to program the DAC
register, offset adjust register, and gain adjust register.

Fault Register

The Fault Register tab allows the user to read the contents
of the fault register. The fault register can also be polled
continuously.

Program Loop Current

The Program Loop Current tab allows the user to program a
loop current value directly by entering the value in milliamps
after having first selected the loop current range that is set by
the Range0 and Range1 link options.

Command Write

The Co m m an d Writ e tab allows the user to read/write all of the
AD5421s registers as well as issue commands.

Rev. A | Page 6 of 12

Evaluation Board User Guide UG-250

09701-004

EVALUATION BOARD SCHEMATICS AND ARTWORK

Figure 4. Schematic of the AD5421 Circuitry

Rev. A | Page 7 of 12

UG-250 Evaluation Board User Guide

09701-005

Figure 5. Schematic of the SDP Board Connector

Rev. A | Page 8 of 12

Evaluation Board User Guide UG-250

09701-006

09701-007

Figure 6. Component Placement Drawing

Figure 7. Component Side PCB Drawing

Rev. A | Page 9 of 12

UG-250 Evaluation Board User Guide

09701-008

Figure 8. Solder Side PCB Drawing

Rev. A | Page 10 of 12

Evaluation Board User Guide UG-250

C12

Capacitor, F/TERM, 100 nF, 50 V, X7R

06035C104KAZ2A

FEC 1301894

D4

Diode ZENER, 4.7 V, 500 MW, SOD-80

FLZ4V7A

Digi-Key FLZ4V7ACT-ND

LK4

2-pin (0.1" pitch) header and shorting shunt

M20-9990246

FEC 1022247 and FEC 150-411

R15

Resistor, HRC11 0805 18M

RC0805JR-0718ML

Yageo (Phycomp) FEC 9236422

U2

Depletion mode, N-channel MOSFET

BSP129

FEC 1214279

ORDERING INFORMATION

BILL OF MATERIALS

Table 3.

Reference
Designator Part Description Part Number Supplier/Number

C5 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C6 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C7 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C8 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C9 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C10 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C11 Capacitor, 1 µF, 16 V, Case A tantalum MCCTA105M016 FEC 1190114

C13 Capacitor, F/TERM, 100 nF, 50 V, X7R 06035C104KAZ2A FEC 1301894
C15 Capacitor, 2.2 µF, 16 V, Case A tantalum MCCTA225M016 FEC 1190115
D1 LED, yellow, 0603 LY Q971-H1K1-36-0-20-R18 Digi-Key 475-2557-1-ND
D2 BAS516, high speed switching diodes BAS516 FEC 8734402
D3 BAS516, high speed switching diodes BAS516 FEC 8734402

J2 Header, TIN, SIL, 32-way 3-826936-2 FEC 5217805 and FEC 1212164 (x7)
J3 Header, TIN, SIL, 32-way 3-826936-2 FEC 5217805 and FEC 1212164 (x7)
J4 Header, TIN, SIL, 32-way 3-826936-2 FEC 5217805 and FEC 1212164 (x7)
J5 2-pin terminal block (5 mm pitch) CTB5000/2 FEC 151789
J6 120-way connector, 0.6 mm pitch FX8-120S-SV(21) FEC 1324660
J7 3-pin terminal block (5 mm pitch) CTB5000/3 FEC 151790
L1 Ferrite bead chip, series FB FB FBMH3225HM102NT FEC 1651731
L2 Ferrite bead chip, series FB FB FBMH3225HM102NT FEC 1651731
LK1 2-pin (0.1" pitch) header and shorting shunt M20-9990246 FEC 1022247 and FEC 150-411
LK2 3-pin SIL header and shorting link M20-9990345 and M7567-05 FEC 1022248 and FEC 150410

LK6 2-pin (0.1" pitch) header and shorting shunt M20-9990246 FEC 1022247 and FEC 150-411
LK7 2-pin (0.1" pitch) header and shorting shunt M20-9990246 FEC 1022247 and FEC 150-411
R1 Resistor, 24 kΩ, 0805, 5 ppm PCF0805-13-24K-B-T1 FEC 1108901
R3 Resistor, 220 kΩ, 5%, 50 V, 0.063W, 0603 MC 0.063W 0603 5% 220K FEC 9331930
R4 Resistor, 1 kΩ, 5%, 50 V, 0.063W, 0603 MC 0.063W 0603 5% 1K FEC 9331697

R16 MULTICOMP, resistor, 0603 953 kΩ MC 0.063W 0603 1% 953K FEC 1171085
R18 RESISTOR, 0603, 100 kΩ, 1% MC 0.063W 0603 1% 100K FEC 9330402
R19 RESISTOR, 0603, 100 kΩ, 1% MC 0.063W 0603 1% 100K FEC 9330402
U1 Loop powered, 4 mA to 20 mA DAC AD5421CREZ AD5421CREZ

U3 Digital isolator ADUM1401ARWZ ADuM1401ARWZ
U5 Digital isolator ADuM1201ARZ ADuM1201ARZ
U6 64K I2C serial EEPROM 24LC64-I/SN FEC 9758070

Rev. A | Page 11 of 12

UG-250 Evaluation Board User Guide

OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO

NOTES

ESD Caution
ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection

circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.

Legal Terms and Conditions

By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions
set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you
have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc.
(“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal,
temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided
for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional
limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term
“Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including
ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may
not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to
promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any
occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board.
Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice
to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION
WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED
TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL
PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF
THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE
AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable
United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of
Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby
submits to the personal jurisdiction and venue of such courts. The United Nations Convention on Contracts for the International Sale of Goods shall not apply to this Agreement and is expressly disclaimed.

©2011 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
UG09701-0-10/11(A)

Rev. A | Page 12 of 12