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Evaluation Board User Guide

UG-391

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 AD5258 Digital Potentiometer

PLEASE SEE THE LAST PAGE FOR AN IMPORTANT

WARNING AND LEGAL TERMS AND CONDITIONS.

Rev. 0 | Page 1 of 16

FEATURES

Full-featured in conjunction with low voltage digiPOT

motherboard (EVAL-MB-LV-SDZ)

Various test circuits

Various ac/dc input signals

PC control via a separately purchased system demonstration

platform (SDP-B or SDP-S)

PC software for control

PACKAGE CONTENTS

EVAL-AD5258DBZ board

EVAL-MB-LV-SDZ motherboard

CD that includes

Self-installing software that allows users to control the

board and exercise all functions of the device

Electronic version of the AD5258 data sheet

Electronic version of the UG-391 user guide

GENERAL DESCRIPTION

This user guide describes the evaluation board for evaluating the

AD5258, a single-channel, 64-position, nonvolatile memory

digital potentiometer in conjunction with the low voltage digiPOT

motherboard.

The AD5258 supports single-supply 2.7 V to 5.5 V operation,

making the device suited for battery-powered applications and

many other applications with superior low temperature

coefficient performance.

In addition, the AD5258 uses a versatile I

C serial interface that

operates in fast mode, allowing speeds of up to 400 kHz. This

interface can be used to read back the wiper register and

EEPROM content.

The EVAL-MB-LV-SDZ can operate in single-supply mode and

incorporates an internal power supply from the USB.

Complete specifications for the AD5258 part can be found in

the AD5258 data sheet, which is available from Analog Devices,

Inc., and should be consulted in conjunction with this user

guide when using the evaluation board.

EVAL-AD5258DBZ WITH MOTHERBOARD AND SDP-B

10619-001

Figure 1. Digital Picture of Evaluation Board with Low Voltage DigiPOT Motherboard and System Demonstration Platform

Summary of content (16 pages)

PAGE 1
Evaluation Board User Guide UG-391 One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.
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UG-391 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Evaluation Board Software ...............................................................6 Package Contents .............................................................................. 1 Installing the Software ..................................................................6 General Description ..............................................
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Evaluation Board User Guide UG-391 EVALUATION BOARD HARDWARE POWER SUPPLIES Link Options The EVAL-MB-LV-SDZ supports using single power supplies. All supplies are decoupled to ground using 10 μF tantalum and 0.1 μF ceramic capacitors. Several link and switch options are incorporated in the EVALMB-LV-SDZ board and should be set up before using the board. Table 2 describes the positions of the links to control the evaluation board by a PC, via the SDP board.
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UG-391 Evaluation Board User Guide TEST CIRCUITS VDD – VSS 1kHz The EVAL-AD5258DBZ and EVAL-MB-LV-SDZ incorporate several test circuits to evaluate the performance of the AD5258. 2 HPF AC+ AC AC_INPUT R34 DAC The RDAC can be operated as a digital-to-analog converter (DAC), as shown in Figure 2. VDD – VSS 2 RDAC A AC+ B A1 W1 W VOUT1 BUF-W1 B1 VDD VDD RDAC A B R35 A1 VDD – VSS 2 W1 W BUF-W1 Figure 3.
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Evaluation Board User Guide UG-391 The RDAC can be operated as an inverting or noninverting signal amplifier supporting linear or pseudologarithmic gains. Table 6 shows the available configurations. C1 10nF A2 R43 B2 W A R42 B RDAC RWB R38 (3) R41 1.7kΩ The inverting amplifier with linear gain is shown in Figure 6, and the gain is defined in Equation 5. VOUT2 R38 2.7kΩ Note that the input signal, VIN, must be negative.
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UG-391 Evaluation Board User Guide EVALUATION BOARD SOFTWARE 2. INSTALLING THE SOFTWARE The EVAL-AD5258DBZ kit includes evaluation board software provided on a CD. The software is compatible with Windows® XP, Windows Vista, and Windows 7 (both 32 bits and 64 bits). If the SDP board is not connected to the USB port when the software is launched, a connectivity error displays (see Figure 7).
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Evaluation Board User Guide UG-391 RDAC has the following option: SOFTWARE OPERATION  The main window of the EVAL-AD5258DBZ software is divided into the following sections: QUICK COMMANDS, MANUAL DATA, RDAC, and MEMORY. QUICK COMMANDS has the following options:  NOP places the device in no operation mode, reducing the power consumption of the device.  STORE saves the value of the RDAC register in the EEPROM memory.  RESTORE transfers the data of the EEPROM memory into the RDAC register.
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UG-391 Evaluation Board User Guide EVALUATION BOARD SCHEMATICS AND ARTWORK 10619-009 MOTHERBOARD Figure 9. SDP Connector and Power Supply Rev.
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Evaluation Board User Guide UG-391 10619-010 Figure 10. Schematic of Test Circuits Rev.
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Evaluation Board User Guide 10619-011 UG-391 Figure 11. Schematic of Connectors to Daughter Board Rev.
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UG-391 10619-012 Evaluation Board User Guide 10619-013 Figure 12. Component Side View 10619-014 Figure 13. Component Placement Drawing Figure 14. Layer 2 Side PCB Drawing Rev.
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UG-391 Evaluation Board User Guide DAUGHTER BOARD 10619-015 Figure 15. Schematic of Daughter Board Rev.
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UG-391 10619-016 Evaluation Board User Guide 10619-017 Figure 16. Component Side View 10619-018 Figure 17. Component Placement Drawing Figure 18. Layer 2 Side PCB Drawing Rev.
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UG-391 Evaluation Board User Guide ORDERING INFORMATION BILL OF MATERIALS Table 7.
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Evaluation Board User Guide UG-391 Table 8. Daughter Board Qty 1 1 3 2 2 1 1 2 1 Reference Designator U2 A1 A2, A3, A4 C2, C4 C1, C3 J1 J2 J3, J4 Description 256-position digital potentiometer 2-pin (0.1" pitch) header and shorting shunt 3-pin SIL header and shorting link 6.3 V tantalum capacitor (Case A), 10 μF, ±20% 50 V, X7R ceramic capacitor, 0.1 μF, ±10% Header, 2.54 mm, PCB, 1 × 8-way 12-pin (2 × 6), 0.1" pitch header 5-pin SIL header FEC refers to Farnell Electronic Component Distributors. Rev.
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UG-391 Evaluation Board User Guide NOTES I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors). 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.