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Evaluation Board User Guide

UG-254

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

Evaluation Board for the AD7298 8-Channel, 1 MSPS, 12-Bit SAR ADC with

Temperature Sensor

PLEASE SEE THE LAST PAGE FOR AN IMPORTANT

WARNING AND LEGAL TERMS AND CONDITIONS.

Rev. A | Page 1 of 16

FEATURES

Full-featured evaluation board for the AD7298 (Rev. C)

Link options

On-board analog bias-up circuit

PC control in conjunction with system demonstration

platform (SDP)

PC software for control

EVALUATION BOARD DESCRIPTION

The EVAL-AD7298SDZ is a full-featured evaluation board

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

AD7298. The evaluation board can be controlled via the SDP

connector (J1). The SDP board allows the evaluation board to

be controlled through the USB port of a PC using the AD7298

evaluation software.

On-board components include: the ADP1706 low dropout CMOS

linear regulator, the AD8022 high speed, a low noise amp, and the

AD8066 high performance 145 MHz FastFET™ amp.

The evaluation board features analog bias-up circuitry. Bipolar

signals are input via the VIN SMB connector and are biased up

by the on-board bias-up buffer circuit. The biased up signal is

available at the BIASED_VIN2 SMB and can be applied to any one

of the eight VINx SMB connectors using an SMB-to-SMB cable.

Various link options are described in the Evaluation Board

Hardware section. The Link Options section of this user guide

should be consulted when configuring the board for standalone

operation.

DEVICE DESCRIPTION

This user guide describes the evaluation board for the AD7298,

which is a 12-bit, 8-channel successive approximation ADC with

internal temperature sensor.

The AD7298 offers a programmable sequencer, which enables

the selection of a preprogrammed sequence of channels for

conversion. The device has an on-chip 2.5 V reference that can

be disabled to allow the use of an external reference.

The AD7298 includes a high accuracy, band gap, temperature

sensor, which is monitored and digitized by the 12-bit ADC to

give a resolution of 0.25°C.

Complete specifications for the AD7298 are provided in the

AD7298 data sheet, available from Analog Devices, Inc., and

should be consulted in conjunction with this user guide when

using the evaluation board.

FUNCTIONAL BLOCK DIAGRAM

SDP

BOARD

SCLK

VBIASEDVIN

DRIVE

IN7

IN0

VDRIVE

USB

CONNECTION

TO PC

BIAS-UP

CIRCUITRY

DOUT

DIN

EVAL-AD7298SDZ

AD7298

3.3V

REGULAR

EXT_VCC AGNDDGND VDRIVE –5V +5VAGND

09711-001

Figure 1.

Summary of content (16 pages)

PAGE 1
Evaluation Board User Guide UG-254 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 the AD7298 8-Channel, 1 MSPS, 12-Bit SAR ADC with Temperature Sensor Various link options are described in the Evaluation Board Hardware section. The Link Options section of this user guide should be consulted when configuring the board for standalone operation. FEATURES Full-featured evaluation board for the AD7298 (Rev.
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UG-254 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Software Installation .....................................................................5 Evaluation Board Description......................................................... 1 Launching the Evaluation Board Software....................................5 Device Description.......................................................................
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Evaluation Board User Guide UG-254 EVALUATION BOARD HARDWARE POWER SUPPLIES LINK OPTIONS Care should be taken before applying power and signals to the evaluation board to ensure that all link positions are as per the required operating mode. Table 1 shows the position in which the links are set when the evaluation board is packaged. The links are set so that the SDP board supplies the control signals and VDRIVE.
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UG-254 Evaluation Board User Guide Table 2.
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Evaluation Board User Guide UG-254 EVALUATION BOARD SOFTWARE SOFTWARE INSTALLATION LAUNCHING THE EVALUATION BOARD SOFTWARE The AD7298 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 the setup.exe file from the CD.
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UG-254 Evaluation Board User Guide SOFTWARE OPERATION FRONT PANEL Figure 3 shows the main window of the AD7298 evaluation software. The device is configurable via the CONTROL REGISTER button. Samples can be taken continuously or one at a time, depending on whether CONTINUOUSLY SAMPLE or SAMPLE ADC is selected. The lower section of the main window graphically displays the AD7298 data.
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UG-254 09711-005 Evaluation Board User Guide Figure 5. Temperature Sensor Results (Note that Either the Temperature Sensor Results or the Averaged Results Display at Any Given Time) SAMPLE ADC/CONTINUOUSLY SAMPLE FLASH LED To gather sample data on the selected channels, click SAMPLE ADC or CONTINUOUSLY SAMPLE. Both buttons are located on the middle of the main window. If CONTINUOUSLY SAMPLE is pressed and the user wishes to stop sampling, click CONTINOUSLY SAMPLE a second time.
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UG-254 Evaluation Board User Guide EVALUATION BOARD SCHEMATICS, ARTWORK, AND SILKSCREEN 09711-006 Figure 6. EVAL-AD7298SDZ Schematic 1 of 3 Rev.
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Evaluation Board User Guide UG-254 09711-007 Figure 7. EVAL-AD7298SDZ Schematic 2 of 3 Rev.
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UG-254 Evaluation Board User Guide 09711-008 Figure 8. EVAL-AD7298SDZ Schematic 3 of 3 Rev.
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UG-254 09711-009 Evaluation Board User Guide 09711-010 Figure 9. Component Side Artwork 09711-011 Figure 10. Solder Side Artwork Figure 11. Component Side Silkscreen Rev.
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UG-254 Evaluation Board User Guide ORDERING INFORMATION BILL OF MATERIALS Table 3. Reference Designator C1, C11, C21, C31 Part Description 1 nF, multilayer ceramic capacitor, 50 V, X7R, ±10% 10 pF multilayer ceramic capacitor, 50 V, NPO, ±5% 0603, capacitor spacing (not inserted) Part Number U0603R102KCT Stock Code FEC 9406174 06035A100JAT2A FEC 499110 Not applicable Not applicable 10 μF, 6.
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Evaluation Board User Guide Reference Designator U1 U2 U3 U4 U5 U8, U9, U10 T_SCLK, PD, T_CS, T_DIN, T_TENSE_B, TDOUT, VCC, VDRIVE BIASED_VIN2, EXT_OFFSET, VIN, VREF_BUFF UG-254 Part Description 8-channel, I2C, 12-bit SAR ADC with temperature sensor Dual high speed, low noise op amp Part Number AD7291BCPZ AD8022ARZ AD8022ARZ High performance, 145 MHz FastFET™ op amp 32 kΩ, I2C serial EEPROM 1 A, low dropout, CMOS linear regulator AD8066ARZ AD8066ARZ 24LC32A-1/MS ADP1706ACPZ-3.
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UG-254 Evaluation Board User Guide NOTES Rev.
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Evaluation Board User Guide UG-254 NOTES Rev.
PAGE 16
UG-254 Evaluation Board User Guide 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.