Texas Instruments DAC1220EVM User manual

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 
August 2004
User’s Guide
SBAU102
Data Acquisition Products

IMPORTANT NOTICE
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enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
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TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
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and applications, customers should provide adequate design and operating safeguards.
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Mailing Address: Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2004, Texas Instruments Incorporated

EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION
PURPOSES ONLY and is not considered by TI to be fit for commercial use. As such, the goods being provided
may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective
considerations, including product safety measures typically found in the end product incorporating the goods.
As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic
compatibility and therefore may not meet the technical requirements of the directive.
Should this evaluation kit not meet the specifications indicated in the EVM User’s Guide, the kit may be returned
within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED,
IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user
indemnifies TI from all claims arising from the handling or use of the goods. Please be aware that the products
received may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). Due to the open construction
of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic
discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE
TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
Please read the EVM User’s Guide and, specifically, the EVM Warnings and Restrictions notice in the EVM
User’s Guide prior to handling the product. This notice contains important safety information about temperatures
and voltages. For further safety concerns, please contact the TI application engineer.
Persons handling the product must have electronics training and observe good laboratory practice standards.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any
machine, process, or combination in which such TI products or services might be or are used.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2004, Texas Instruments Incorporated

EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the specified input and output ranges of 0V to 5V that
are described in the EVM User’s Guide.
Exceeding the specified input range may cause unexpected operation and/or irreversible
damage to the EVM. If there are questions concerning the input range, please contact a TI
field representative prior to connecting the input power.
Applying loads outside of the specified output range may result in unintended operation and/or
possible permanent damage to the EVM. Please consult the EVM User’s Guide prior to
connecting any load to the EVM output. If there is uncertainty as to the load specification,
please contact a TI field representative.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2004, Texas Instruments Incorporated

Contents
iii
Contents
Preface
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About This Manual
This manual describes the DAC1220EVM evaluation fixture and how to use
it. Throughout this document, the abbreviation EVM and the term evaluation
module are synonymous with the DAC1220EVM.
Related Documentation From Texas Instruments
The following documents provide information regarding Texas Instruments
integrated circuits used in the assembly of the DAC1220EVM. These docu-
ments are available from the TI web site, and are current at the time of the
writing of this User’s Guide. To obtain a copy of the following TI documents,
visit our website at http://www.ti.com/ or call the Texas Instruments Litera-
ture Response Center at (800) 477−8924 or the Product Information Center
at (972) 644−5580. When ordering, identify the document by both title and
literature number.
Data sheet Literature number
DAC1220 Data Sheet SBAS273
REF1004 Data Sheet SBVS002
OPA335 Data Sheet SBOS245
OPA350 Data Sheet SBOS099
SN74LVC1G80 Data Sheet SCES221
Additional Documentation
The following document provides information regarding selected non-TI
components, which may be used in the testing of the DAC1220EVM. This
document is available from the corresponding manufacturer.
Document Manufacturer
HPA449 User’s Guide SoftBaugh, http://www.softbaugh.com

Contents
iv
If You Need Assistance
If you have questions regarding either the use of this evaluation module or
the information contained in the accompanying documentation, please con-
tact the Texas Instruments Product Information Center at (972) 644−5580
or visit the TI web site at www.ti.com.
FCC Warning
This equipment is intended for use in a laboratory test environment only. It
generates, uses, and can radiate radio frequency energy and has not been
tested for compliance with the limits of computing devices pursuant to sub-
part J of part 15 of FCC rules, which are designed to provide reasonable
protection against radio frequency interference. Operation of this equip-
ment in other environments may cause interference with radio communica-
tions, in which case the user at his own expense will be required to take
whatever measures may be required to correct this interference.
Trademarks
SPI is a registered trademark of Motorola, Inc.
I2C is a registered trademark of Royal Philips Electronics B.V., The Nether-
lands.
All other trademarks are the property of their respective owners.

Contents
v
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1 Overview 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Introduction 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Built-In Accessories 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Connectors 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 Controls 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Setting Up 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Circuit Description 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 DAC1220 and Ancillary Components 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.1 Filter Capacitors 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.2 Power 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Clock Oscillator 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Voltage Reference 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Output Buffer Amplifier 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Layout 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Usage 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 I/O Connectors and Testpoints 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.1 J1: Analog Connector 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.2 J2: Serial Connector 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.3 J4: Power Connector 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.4 Testpoints 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Jumpers 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1 J3: DAC1220 Supply Current Measurement Jumpers 3-6. . . . . . . . . . . . . . . . . . . . . . .
3.2.2 J5: DAC1220 Analog-Digital Ground Shorting Jumpers 3-6. . . . . . . . . . . . . . . . . . . . .
3.3 Switches 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1 S1: Reference Input Select 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.2 S2: System Clock Select 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Schematic and Layout 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1 Schematic 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Board Layout 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Bill of Materials 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
vi
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3−1. DAC1220EVM Connectors and Testpoints 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−2. Analog Connector Pinout for the DAC1220EVM 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−3. Serial Connector Pinout for the DAC1220EVM 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−4. Power Connector Pinout for the DAC1220EVM 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−5. DAC1220EVM Jumpers 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−6. Jumper Block J3 on the DAC1220EVM 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−7. DAC1220EVM Switches 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−1. DAC1220EVM Schematic 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−2. DAC1220EVM—Layer 1 (Top) 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−3. DAC1220EVM—Layer 2 (Bottom) 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3−1. Analog Connector Pin Descriptions for the DAC1220EVM 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−2. Serial Connector Pin Descriptions for the DAC1220EVM 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3−3. Power Connector Pin Descriptions for the DAC1220EVM 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4−1. Bill of Materials 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
Overview
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The DAC1220EVM is an evaluation fixture designed for the DAC1220 20-bit
delta-sigma (∆Σ) digital-to-analog data converter. The EVM is designed for
prototyping and evaluation, and includes a reference circuit, an oscillator circuit,
and an output buffer amplifier. Use of the output buffer amplifier is optional.
Topic Page
1.1 Introduction 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Built-In Accessories 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Connectors 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 Controls 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Setting Up 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1

Introduction
1-2
1.1 Introduction
Many data converter evaluation fixtures contain a computer interface or a
microcontroller, but the DAC1220EVM contains only the DAC1220 device and
a few supporting components. All DAC1220 pins are accessible through
various pins on the analog and digital connectors of the DAC1220EVM.
The DAC1220EVM is designed using a simple card format developed by TI.
This simple, consistent design makes the DAC1220EVM very easy to connect
to your own prototype system. One can even think of the DAC1220EVM as an
alternate package for the DAC1220—one much larger than the device itself,
but also much easier to wire up by hand on a test bench.
The DAC1220EVM can be plugged directly into suitable motherboards, such
as the HPA449 MSP430 microcontroller development system from Soft-
Baugh, Inc. (http://www.softbaugh.com). See also TI’s web site for example
code using the DAC1220EVM with the HPA449.
The DAC1220EVM, together with the HPA449 and the appropriate software,
also forms a complete evaluation system for verifying the DAC1220 perfor-
mance. See the Texas Instruments web site for additional information and soft-
ware.
1.2 Built-In Accessories
The DAC1220EVM includes a system clock generator and a low-noise voltage
reference. Using either of these components is optional; you can select an ex-
ternal system clock and/or an external reference, using the slide switches on
the EVM.
The +2.5V reference circuit is based on a REF1004-2.5 voltage reference. Its
noise performance is sufficient to allow the DAC1220 to perform at its lowest
noise level.
The on-board clock circuit uses a 2.4576MHz crystal. A switch selects be-
tween the crystal and an external clock signal applied to the TOUT pin of the
serial connector, J2.