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AD9524 failed to lock

Hi,

 I have a AD9524/PCBZ(REV C), and PC is win10 64-bit.

The software is the newest version on the website(v2.1.3).

The AD9524 architecture is like this

I got good connection with the EVB including reading and writing the registers, so I suspect that the software is not the problem.

 

I check to see if PLL1 is working well by observing the output of PLL1_OUT, and the bit that indicates PLL1’s locking status.

 

Due to the VCO on the board is 122.88MHz. So I generated the same frequency cosine wave(122.88MHz, 10dBm=707.1mV) and inserted it to REFA.

 

Then I check the status, it said REF A receiver successfully received the signal and the VCXO did, too.

The PLL1_OUT showed nothing when VCXO output driver is off, and showed the harmonics when VCXO output driver is on.

Is there anyone could tell me the probable cause that makes the PLL1 failed to lock.

 

Appreciate,

 Gordon

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  • Hi,

    I believe the problem is the PLL2 charge pump current set to 0. I set it to the max, just to get you going. Then you can reduce it to a more suitable value. Also, the outputs are set to stay in high impedance. You should select a driver for them.

    I attached the updated stp file. YOu need to zip the files before uploading them.

    ad9524_fail_to_lock2.zip

    Petre

  • Thank you for your assistance. But it doesn't work.
    PLL1 still failed to lock.

    By the way, I did't set the current of PLL2's CP because I tried to simplify the failure by only enable and observer PLL1.

  • HI,

    I played today with the AD9524 evaluation board. I got both PLLs to lock and the AD9524 to generate outputs.

    For some reason, I cannot attach a file to this response, so I cannot show the status window of the software or attach the stp file.

    Below is the content of the stp file I created. Copy it, put it into a file, give it the stp extension and load it into the evaluation software.

    On the evaluation board, make sure P4 jumper is between pins REF_SEL and LOW, so REFA is selected.

    I enabled REFA as differential receiver in INP receivers window.

    Enable the anti-backlash periods for both PLLs. I set the charge pump current at max for both PLLs, but once you get them to lock, you can start to reduce it.

    Set the outputs with LVPECL drivers because the evaluation board manual states the output circuit is ideal for this driver.

    Petre

    ;Header contains information about the setup file and revision
    <Header>
    Product = AD9524
    FileVersion = 1.0
    DecimalSeparator=. ;Used for internationalization
    </Header>

    <RegisterMap>
    &h0,&b00000000 ;00 Hex, 000 Dec
    &h2,&b01110000 ;70 Hex, 112 Dec
    &h3,&b00000011 ;03 Hex, 003 Dec
    &h4,&b00000000 ;00 Hex, 000 Dec
    &h5,&b00000000 ;00 Hex, 000 Dec
    &h6,&b00000000 ;00 Hex, 000 Dec
    &h10,&b00000000 ;00 Hex, 000 Dec
    &h11,&b00000000 ;00 Hex, 000 Dec
    &h12,&b00000000 ;00 Hex, 000 Dec
    &h13,&b00000000 ;00 Hex, 000 Dec
    &h14,&b00000000 ;00 Hex, 000 Dec
    &h15,&b00000000 ;00 Hex, 000 Dec
    &h16,&b00000000 ;00 Hex, 000 Dec
    &h17,&b00000000 ;00 Hex, 000 Dec
    &h18,&b01111111 ;7F Hex, 127 Dec
    &h19,&b00010011 ;13 Hex, 019 Dec
    &h1A,&b00101001 ;29 Hex, 041 Dec
    &h1B,&b00010000 ;10 Hex, 016 Dec
    &h1C,&b00001000 ;08 Hex, 008 Dec
    &h1D,&b00000000 ;00 Hex, 000 Dec
    &h1E,&b00000000 ;00 Hex, 000 Dec
    &h1F,&b00000000 ;00 Hex, 000 Dec
    &h20,&b00000000 ;00 Hex, 000 Dec
    &hF0,&b11111111 ;FF Hex, 255 Dec
    &hF1,&b11000111 ;C7 Hex, 199 Dec
    &hF2,&b00010011 ;13 Hex, 019 Dec
    &hF3,&b00000010 ;02 Hex, 002 Dec
    &hF4,&b01000000 ;40 Hex, 064 Dec
    &hF5,&b00000000 ;00 Hex, 000 Dec
    &hF6,&b00000000 ;00 Hex, 000 Dec
    &hF7,&b00000000 ;00 Hex, 000 Dec
    &hF8,&b00000000 ;00 Hex, 000 Dec
    &hF9,&b00000000 ;00 Hex, 000 Dec
    &hFA,&b00000000 ;00 Hex, 000 Dec
    &h190,&b00100000 ;20 Hex, 032 Dec
    &h191,&b00011111 ;1F Hex, 031 Dec
    &h192,&b00000100 ;04 Hex, 004 Dec
    &h193,&b00100000 ;20 Hex, 032 Dec
    &h194,&b00011111 ;1F Hex, 031 Dec
    &h195,&b00000100 ;04 Hex, 004 Dec
    &h196,&b00000001 ;01 Hex, 001 Dec
    &h197,&b00011111 ;1F Hex, 031 Dec
    &h198,&b00000100 ;04 Hex, 004 Dec
    &h199,&b00000001 ;01 Hex, 001 Dec
    &h19A,&b00011111 ;1F Hex, 031 Dec
    &h19B,&b00000100 ;04 Hex, 004 Dec
    &h19C,&b00000001 ;01 Hex, 001 Dec
    &h19D,&b00011111 ;1F Hex, 031 Dec
    &h19E,&b00000100 ;04 Hex, 004 Dec
    &h19F,&b00000001 ;01 Hex, 001 Dec
    &h1A0,&b00011111 ;1F Hex, 031 Dec
    &h1A1,&b00000100 ;04 Hex, 004 Dec
    &h1A2,&b00000000 ;00 Hex, 000 Dec
    &h1A3,&b00011111 ;1F Hex, 031 Dec
    &h1A4,&b00000100 ;04 Hex, 004 Dec
    &h1A5,&b00100000 ;20 Hex, 032 Dec
    &h1A6,&b00011111 ;1F Hex, 031 Dec
    &h1A7,&b00000100 ;04 Hex, 004 Dec
    &h1A8,&b00000000 ;00 Hex, 000 Dec
    &h1A9,&b00011111 ;1F Hex, 031 Dec
    &h1AA,&b00000100 ;04 Hex, 004 Dec
    &h1AB,&b00100000 ;20 Hex, 032 Dec
    &h1AC,&b00011111 ;1F Hex, 031 Dec
    &h1AD,&b00000100 ;04 Hex, 004 Dec
    &h1AE,&b00000001 ;01 Hex, 001 Dec
    &h1AF,&b00011111 ;1F Hex, 031 Dec
    &h1B0,&b00000100 ;04 Hex, 004 Dec
    &h1B1,&b00000001 ;01 Hex, 001 Dec
    &h1B2,&b00011111 ;1F Hex, 031 Dec
    &h1B3,&b00000000 ;00 Hex, 000 Dec
    &h1B4,&b00000000 ;00 Hex, 000 Dec
    &h1B5,&b00011111 ;1F Hex, 031 Dec
    &h1B6,&b00000100 ;04 Hex, 004 Dec
    &h1B7,&b00100000 ;20 Hex, 032 Dec
    &h1B8,&b00011111 ;1F Hex, 031 Dec
    &h1B9,&b00000100 ;04 Hex, 004 Dec
    &h1BA,&b00000000 ;00 Hex, 000 Dec
    &h1BB,&b00000000 ;00 Hex, 000 Dec
    &h22C,&b11100111 ;E7 Hex, 231 Dec
    &h22D,&b00000000 ;00 Hex, 000 Dec
    &h22E,&b00000000 ;00 Hex, 000 Dec
    &h22F,&b00000000 ;00 Hex, 000 Dec
    &h230,&b00000010 ;02 Hex, 002 Dec
    &h231,&b00000011 ;03 Hex, 003 Dec
    &h232,&b00000000 ;00 Hex, 000 Dec
    &h233,&b00000000 ;00 Hex, 000 Dec
    &h234,&b00000000 ;00 Hex, 000 Dec
    &hA00,&b00000000 ;00 Hex, 000 Dec
    &hA01,&b00000000 ;00 Hex, 000 Dec
    &hA02,&b00000000 ;00 Hex, 000 Dec
    &hA03,&b00000010 ;02 Hex, 002 Dec
    &hA04,&b00000000 ;00 Hex, 000 Dec
    &hA05,&b00000100 ;04 Hex, 004 Dec
    &hA06,&b00001110 ;0E Hex, 014 Dec
    &hA07,&b00000000 ;00 Hex, 000 Dec
    &hA08,&b00010000 ;10 Hex, 016 Dec
    &hA09,&b00001110 ;0E Hex, 014 Dec
    &hA0A,&b00000000 ;00 Hex, 000 Dec
    &hA0B,&b11110000 ;F0 Hex, 240 Dec
    &hA0C,&b00101011 ;2B Hex, 043 Dec
    &hA0D,&b00000001 ;01 Hex, 001 Dec
    &hA0E,&b10010000 ;90 Hex, 144 Dec
    &hA0F,&b00000001 ;01 Hex, 001 Dec
    &hA10,&b00000001 ;01 Hex, 001 Dec
    &hA11,&b11100000 ;E0 Hex, 224 Dec
    &hA12,&b00000011 ;03 Hex, 003 Dec
    &hA13,&b00000010 ;02 Hex, 002 Dec
    &hA14,&b00110000 ;30 Hex, 048 Dec
    &hA15,&b10000000 ;80 Hex, 128 Dec
    &hA16,&b11111111 ;FF Hex, 255 Dec
    &hB00,&b00000000 ;00 Hex, 000 Dec
    &hB01,&b00000000 ;00 Hex, 000 Dec
    &hB02,&b00000000 ;00 Hex, 000 Dec
    &hB03,&b00000000 ;00 Hex, 000 Dec
    </RegisterMap>

    <PinStates>
    PortA=&h1E ;Bit0=USBStatus, Bit1=CSB, Bit2=ResetB, Bit3=SyncB, Bit4=PDB, Bit5=RefSel
    </PinStates>

    <SoftwareSettings>
    AutoSendUpdate=1 ;AutoIOUpdate Setting
    REF_A = 122.8000
    REF_B = 30.7200
    REF_TEST = 10.0000
    VCXO = 122.880
    </SoftwareSettings>

  • HI pminc48,

    Deeply appreciate your assistance .

    If it is convenience to you, would you please kindly send the stp file or related picture file to me?

    my email is

    gordon.chi@anstek.com.tw

    or
    avatarofcliff@hotmail.com

  • ad9524_fail_to_lock3.zip

    HI,

    for some reason, today I was allowed to upload files. Here they are

    Petre

  • Thank you, the stp file help me lock both PLLs and output correct signals.
    I will take time to understand the difference between your stp file and mine.

    But I have a further question, I can't save the configuration to the EEPROM.

    Every time I power down the EVB, the last setting cannot be loaded out.

    Without writing the configuration to EVB again, the EVB won't work.

    Could you please teach me how to use the EEPROM correctly, to make EVB remember my configuration.

    Thanks again.

  • HI,

    sorry for getting back to you so late. There is no need for you to open another issue on the same topic.

    The evaluation software has the EEPROM button that manages the EEPROM. See UG-169, the manual of the evaluation board (you can download it from here: https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-AD9524.html#eb-overview), page 11 on how to proceed.

    Do you want to say you tried this and it did not work?

    Petre

  • Thank you for your reply and sorry for opening another post.

    I will report the result after trying your solution.

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