Analog Devices AD9522 Series Скачать руководство пользователя страница 8

UG-077 

Evaluation Board User Guide 

 

Rev. 0 | Page 8 of 16 

The AD9522 evaluation software is composed of subsections 
that correspond to the AD9522’s major functional blocks. 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.  
When a subwindow closes after clicking 

OK

, the 

WRITE

 box 

on the main window (under the 

REGISTER W/R 

control 

section) may blink red. This indicates that there are settings that 
have not been loaded to the AD9522 evaluation board. Clicking 
the blinking red 

WRITE

 box loads these settings to the 

evaluation board. 

PLL REFERENCE INPUT WINDOW 

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Figure 9. AD9522 Reference Input Control Window 

The reference input control window is shown in Figure 9,  
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 10).  

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Figure 10. Buffer Symbol 

This window is used to enable the PLL reference inputs, which 
are powered down by default. 
 
 
 

Select 

Enable REF 1,

 or 

Enable REF 2,

 or both to enable the 

appropriate reference input, and click 

OK

 when finished. If a 

differential input is used, select the 

Use Differential Ref Mode

 

(Unchecked = Single-Ended Mode)

 check box

Note that this 

mode should not be used simultaneously with 

Enable REF 1

 or 

Enable REF 2.

  

If 

Disable Switchover De-Glitch

 is activated, the AD9522 

maintains the phase relationship between the active input and 
PLL output during a reference switchover. Otherwise, the 
AD9522 minimizes the phase disturbance at the output during 
a reference switchover.  

Enable XTAL Oscillator

 should be selected if you intend to 

connect a crystal to the reference input. 

Enable PLL CMOS Ref Input DC Offset

 forces the dc bias 

point of the single-ended reference input to be different from 
the switching point, and is useful for preventing an ac-coupled 
input from chattering when the reference input is lost. 

PLL CONFIGURATION WINDOW (CONFIG PLL) 

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Figure 11. AD9522 PLL Configuration Window 

The PLL configuration window shown in Figure 11 has three 
sections. This window is opened by clicking the 

Config PLL

 

button on the main window. 
The 

SyncB Counter Reset Mode

 section indicates whether the 

R, A, and B counters are reset when the SYNC pin is activated, 
and controls 0x019[7:6]. See the AD9522 data sheet for more 
details. 
The 

PLL Status Registers

 section allows you to see the current 

value of the read-only PLL status register, Address 0x01F. This 
function is very useful for ensuring that the AD9522 VCO has 
finished VCO calibration and that the PLL is locked. 
The 

Settings

 section controls the various PLL settings such 

as holdover. The AD9522 data sheet describes these functions 
in detail. 

Содержание AD9522 Series

Страница 1: ...ttenuation Clock distribution GENERAL DESCRIPTION The AD9522 x hereafter referred to as AD9522 is a very low noise PLL clock synthesizer featuring an integrated VCO clock dividers and up to 24 outputs...

Страница 2: ...nfiguration Window Config PLL 8 REFMON STATUS and LD Buttons 9 Register W R Box 9 SYNC PD Power Down and RESET Buttons 9 EEPROM Control Window 9 Reference R Divider Window 9 Feedback N Divider Window...

Страница 3: ...ct that signal to the J13 SMA connector DC coupling is recommended in applications requiring automatic hitless reference switching There is a possibility that the AD9522 receive buffer can chatter whe...

Страница 4: ...w indicating that the evaluation board was found or red text appears indicating that the evaluation board was not found 2 If the evaluation board is found click anywhere in the pop up window with the...

Страница 5: ...MODE box found at the top of the main window see Figure 8 2 Enter the intended reference input frequency in megahertz in the REF 1 MHz box at the upper left corner of the main window 3 Click the tria...

Страница 6: ...modified 10 Set the VCO divider by clicking the green VCO box in the center of the main window immediately to the left of the Cal VCO button 11 Power down unused drivers by clicking the numbered tria...

Страница 7: ...Evaluation Board User Guide UG 077 Rev 0 Page 7 of 16 EVALUATION SOFTWARE COMPONENTS MAIN WINDOW 08747 008 Figure 8 AD9522 Evaluation Software Main Window...

Страница 8: ...Single Ended Mode check box Note that this mode should not be used simultaneously with Enable REF 1 or Enable REF 2 If Disable Switchover De Glitch is activated the AD9522 maintains the phase relation...

Страница 9: ...issue an I O update command whenever registers are written to the AD9522 SYNC PD POWER DOWN AND RESET BUTTONS The SYNC PD and RESET buttons allow you to control these pins on the AD9522 Each button ha...

Страница 10: ...r value For example it is not possible to use the internal VCO and a feedback divider of 30 However the R divider can be doubled which allows a feedback divider of 60 The feedback divider window has a...

Страница 11: ...ow shown in Figure 19 is accessed by clicking the Cal VCO button on the main window A valid reference input signal must be present to complete VCO calibration and the VCO must be recalibrated any time...

Страница 12: ...nation require ments and OUT9 through OUT11 have been terminated differently from OUT0 through OUT8 OUT0 through OUT8 are ac coupled and this termination scheme is ideal for LVDS drivers However this...

Страница 13: ...a recently connected evaluation board 08747 022 Figure 25 USB Device Selection Window Configure Serial Port The I O Interface window allows you to control how the USB controller interacts with the AD9...

Страница 14: ...hoice Typical phase detector frequencies for these applications are 10 MHz to 100 MHz and typical loop bandwidths for this loop filter are 50 kHz to 500 kHz depending on the configuration The user sho...

Страница 15: ...Configuration A dialog box appears and acknowledges the I2 C mode and address The evaluation software starts at I2 C Address 0x058 and stops at the first valid I2 C address that it finds If the targe...

Страница 16: ...set in the register setup stp file because the user normally initiates VCO calibration manually while running the evaluation software To avoid a checksum mismatch it is recommended that the user manu...

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