Datasheet

ManualsBrandsANALOG DEVICES ManualsLinear ICsAD9520-1BCPZ

Table Of Contents

Evaluation Board User Guide

UG-076

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

AD9520-x Evaluation Board

See the last page for an important warning and disclaimers. Rev. 0 | Page 1 of 16

FEATURES

Simple power connection using 6 V wall adapter and

on-board LDO voltage regulators

LDOs are easily bypassed for power measurements

5 ac-coupled differential LVPECL SMA connectors

7 LVPECL differential headers for additional outputs

SMA connectors for

2 reference inputs

Charge pump output

Clock distribution input

USB connection to PC

Microsoft Windows-based evaluation software

with simple graphical user interface

On-board PLL loop filter

Easy access to digital I/O and diagnostic signals via

I/O header

Status LEDs for diagnostic signals

APPLICATIONS

Clocking of analog-to-digital and digital-to-analog

converters up to 2.9 GHz

Networking and communications line cards

Test and measurement equipment

Wireless base stations, controllers

Clock cleanup/jitter attenuation

Clock distribution

GENERAL DESCRIPTION

The AD9520-x (hereafter referred to as AD9520) is a very low

noise PLL clock synthesizer featuring an integrated VCO, clock

dividers, and up to 24 outputs. The AD9520 features automatic

holdover and a flexible reference input circuit allowing for very

smooth reference clock switching. The AD9520 family also

features the necessary provisions for an external VCXO.

The AD9520 evaluation board is a compact, easy-to-use

platform for evaluating all features of the AD9520. This user

guide covers all six versions of the AD9520 family.

Although the Quick Start Guide to the AD9520 PLL section

applies specifically to the AD9520-4, increasing the N (feed-

back) divider and channel divider increases the VCO frequency

to the allowable frequency range of other AD9520 versions.

For the AD9520-5, which lacks the internal VCO, certain

portions of this user guide that apply to the internal VCO (such

as VCO calibration) can be ignored.

This document covers the AD9520 family. The AD9522 family,

which is identical to the AD9520 except that it has LVDS

outputs, is covered in UG-077.

For convenience, detailed information from the AD9520 data

sheet has been included here. Use this user guide in conjunction

with the AD9520 and AD9522 data sheet and software

documentation available at www.analog.com.

AD9520 EVALUATION BOARD

8746-001

Figure 1.

Summary of content (16 pages)

PAGE 1
Evaluation Board User Guide UG-076 One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.
PAGE 2
UG-076 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 SYNC, PD (Power Down), and RESET Buttons .......................9 Applications ....................................................................................... 1 EEPROM Control Window .........................................................9 General Description .........................................................................
PAGE 3
Evaluation Board User Guide UG-076 EVALUATION BOARD HARDWARE Connect an oscilloscope, spectrum analyzer, or other lab equipment to any of the J0 to J9 SMA connectors on the right side of the board. The following instructions are for setting up the physical connections to the AD9520 evaluation board. When connecting the evaluation board to a PC for the first time, the user must install the evaluation software prior to connecting the evaluation board. POWER AND PC CONNECTIONS 1. 2. 3. 4.
PAGE 4
UG-076 Evaluation Board User Guide EVALUATION BOARD SOFTWARE Do not connect the evaluation board until the software installation is complete. 1. 2. 3. The latest evaluation software and documentation can be downloaded from www.analog.com. If the software was downloaded, skip to Step 3. If using the CD, insert the AD9520 evaluation software CD. Doubleclick My Computer, and then double-click the AD9520EV CD icon.
PAGE 5
Evaluation Board User Guide UG-076 QUICK START GUIDE TO THE AD9520 PLL When the evaluation software is installed, the evaluation board is connected, and the software is loaded, use the following steps to configure and lock the PLL. These steps assume that the input signal is present, the evaluation board has not been modified, and that the PLL loop filter is suitable for the user’s application. This quick start guide covers only simple PLL operation to start the PLL.
PAGE 6
UG-076 Program the R (reference) divider by clicking the R DIVIDER box at the top of the main window. Set the desired value and click OK (see Figure 13). 7. Program the N (feedback) divider by clicking the N DIVIDER box at the top of the main window. Set the desired value and click OK. For this example, N = 5500 can use 8/9 dual modulus mode with A = 4 and B = 687. 8. Set the charge pump current (1.2 mA in this case) by clicking the CHARGE PUMP box in the upper right corner of the main window, and click OK.
PAGE 7
Evaluation Board User Guide UG-076 EVALUATION SOFTWARE COMPONENTS 08746-005 MAIN WINDOW Figure 8. Evaluation Software Main Window The AD9520 evaluation software is composed of subsections that correspond to the major functional blocks of the AD9520. These subsections are listed in the following sections, and each of these has its own window. From the main window, each functional block can be accessed by clicking that block in the main window.
PAGE 8
UG-076 Evaluation Board User Guide PLL CONFIGURATION WINDOW The Reference Input Control window is shown in Figure 10 and is accessed by clicking either of the triangular buffer symbols immediately to the right of the REF 1 (MHz) and REF 2 (MHz) input reference frequency boxes (see Figure 9). The PLL Configuration window shown in Figure 11 is opened by clicking the Config PLL button on the main screen. The window has three sections: SyncB Counter Reset Mode, PLL Status Registers, and Settings.
PAGE 9
Evaluation Board User Guide UG-076 REGISTER W/R BOX The REGISTER W/R (write/read) box has three buttons and three check boxes. The WRITE button transfers the values stored in the evaluation software to the evaluation board. It blinks red when register values have changed. The READ button transfers the values stored in the evaluation board to the evaluation software. The UPDATE button issues an I/O update command by writing 0x01 to Register 0x232.
PAGE 10
UG-076 Evaluation Board User Guide R AND N DELAY WINDOW The N Divider window shown in Figure 14 is accessed by clicking the N DIVIDER box. It allows you to set the feedback divider. If this box is colored gray, the PLL is off. To turn the PLL on, click the PLL MODE box at the top of the main window and select Norm Op. The N delay window shown in Figure 15 is accessed by clicking the N DELAY box on the main window. The R DELAY box is identical to the N DELAY box.
PAGE 11
Evaluation Board User Guide UG-076 VCO CALIBRATION WINDOW The Charge Pump Setup window shown in Figure 17 is accessed by clicking the CHARGE PUMP box on the main window. The Calibrate VCO window shown in Figure 19 is accessed by clicking the Cal VCO button on the main window. 08746-013 08746-015 CHARGE PUMP SETUP WINDOW Figure 19. Calibrate VCO Window Figure 17. Charge Pump Setup Window This window is most often used to vary the charge pump current.
PAGE 12
UG-076 Evaluation Board User Guide OUTPUT DRIVER WINDOW The output driver window shown in Figure 22 is accessed by clicking any of the numbered triangular output driver symbols on the right side of the main window (see Figure 21). OUT 0 through OUT8 are ac-coupled with 200 Ω pull-down resistors on each output. This termination scheme is ideal for LVPECL drivers. However, this scheme degrades the CMOS driver performance.
PAGE 13
Evaluation Board User Guide UG-076 08746-027 EVALUATION SOFTWARE MENU ITEMS Figure 24. Menu Bar MENU BAR Configure Serial Port File Menu The I/O Interface window allows you to control how the USB controller interacts with the AD9520 serial port (see Figure 26). The file menu has the following options: Load Setup Selecting Load Setup loads a previously saved AD9520 setup file (.stp). A setup file is a text file that contains the AD9520 register setup file, plus any evaluation board settings.
PAGE 14
UG-076 Evaluation Board User Guide AD9520 PLL LOOP FILTER The AD9520 PLL requires an external loop filter whose components are tailored for different applications. The thirdorder passive configuration shown in Figure 27 usually offers the best performance for many applications and is the one found on the evaluation board. AD9520 LF VCO ADIsimCLK Version 1.3 includes specific support for the AD9520. However, the AD9516, AD9520, and AD9522 share the same loop dynamics. Therefore, ADIsimCLK Version 1.
PAGE 15
Evaluation Board User Guide UG-076 USING THE EVALUATION BOARD TO PROGRAM AN AD9520 ON A CUSTOMER BOARD This guide shows how to use an AD9520 evaluation board to program an AD9520 on a customer board via the I2C interface. It assumes that the user has access to the I2C pins via a header on the target board, and knows the assigned address of the target I2C device. 5. 7. Click Reset Serial Port and then click Detect Current Configuration. A dialog box appears and acknowledges the I2C mode and address.
PAGE 16
UG-076 Evaluation Board User Guide AD9520 BINARY FILE GENERATION The AD9520 evaluation software can be used to generate binary setup files that can be used by EEPROM programmers, such as those made by BPM Microsystems. Clicking Generate Binary File from the File menu prompts the user to enter a filename. The .bin extension is assumed. There is no facility for loading a .bin file into the software. The binary file format is such that Byte Offset 0 in the binary file contains the value for Register 0x000.