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I wonder HMC807

Hi. I am using HMC807.

But Pll lock is released by low temperature. What should I do? and could you chack setting of regiseter Send you? We are taking Ref 50MHz signal and shoot 13GHz output.

  • hmc807 can't  work    can  you  give   me  your   Loop Filter design for example   and  the value of regisiter   

    it's my  program   and   Loop Filter

    0 485901
    1 86
    2 1
    3 81
    5 50894C
    6 702F87
    7 4FA
    8 31DF
    9 900200
    A 0
    B 72
    C 0
    D A
    E 0
    F 1

  • Thank you for your answer.

    I wonder a few more questions.

    Are you the same with me? HMC807 TEST.

    Our registration is as below.

    1 86

    2 0x2

    3 104

    5 50894C

    6 703387

    7 4FA

    8 31DF

    9 9000000

    A 0

    B 72

    C 0

    D A

    E not use

    F not use

    Should we use E or F?

    Is there a problem with the registration value of the data sheet?

    Reg 02h REFDIV Register  01h-divider-by-1(bypass)  01h-divider-by-2  01h-divider-by-3 etc...Is it the right sequence?

    and RFout/2  Is it always used?

    I wait you answer.

  • Hi there,

    Sorry to hear you're having trouble keeping the HMC807 phase locked over temperature. I'll try to help based on the information provided. So at 13GHz at RFout, 6.5GHz will be routed to the internal PLL. Since you're using a 50MHz reference and REG2 (RDIV)= 2h your PFD frequency is 6.5GHz / (50MHz / 2) = N= 260. Operating in integer mode.

    Loop stability may be one part of the problem. You can use ADISimPLL to synthesize your loop. Reducing the PFD frequency pulls the corner of the loop filter in and increases the in-band phase noise. This may also degrade the phase margin which should ideally fall between 40-70 degrees over temperature in order to remain stable. A phase margin of 55 deg is a good place to start to insure loop is very stable over temp.

    After powering up should send REG01[1] to initialize all registers to their default values.

    Evaluation of your register values: .

    REG01[1] - add to initialize PLL after power up

    1 86 (RST) = o.k.

    2 0x2  (REFDIV = 2) so PFD = 25MHz if using a 50MHz reference.

    3 104  (INT)  = 260d = correct,

    5 50894C (SD Seed) = o.k., any value except 0 is acceptable, SD isn't being used in INT mode anyway.

    6 703387 (SD CFG) = o.k.

    7 4FA = (LD / CSP) 25MHz PFD = 40nS period. For integer mode the LD window should be set at ½ the PFD period or 20nS in this case. This provides enough margin for the PVT variation. - o.k.

    8 31DF (Analog En) = o.k.

    9 9000000 (Charge Pump) - too many bits here - I'm guessing you mean 900000h. CP_Up / Down = 2mA = o.k.

    A 0 (CP bias) = Default = o.k.

    B 72 (PFD) - o.k. if using the loop on evaluation board. Generally speaking this loop configuration isn't the best as it may not always allow the very low end of the band to be reached (2V). I would recommend the Active Loop C configuration used on the HMC778LP6CE and change REGB = 7A (or possibly 87A as REGb[11] = Reserved '1'.

    C 0 (VCO SPI) = o.k.

    D A (GPO_SPI) = D1 & D0 not available so not really used on HMC807 - o.k.

    E not use (Reserved)

    F not use (Lock Detect Status)

    4 (FRAC) = 0 (not shown / not used)

    Should we use E (Reserved so no) or F (Lock Detect Status, 0 = not locked, 1 = locked)See REG08 [6] as well

    Is there a problem with the registration value of the data sheet?

    Reg 02h REFDIV Register  01h-divider-by-1(bypass)  01h-divider-by-2  01h-divider-by-3 etc...Is it the right sequence? - No - See attached user guide.

    00h - illegal

    01h - divide-by-1 (bypass)

    10h - divide-by-2

    11h - divide-by-3 etc

    and RFout/2  Is it always used? Yes RFout/2 always used (internally bonded).  Refer to

    Best Regards,

    Marty

    attachments.zip
  • my   hmc807  can't  work   can you help  me   .  I   need  a  output  of  13GHz  with    100MHz reference.the loop filter is designed  by   hitt_pll desine  tool .

  • my  e-mail   519499708@qq.com    you  can   seed a  email  for  me

  • Thank you for your concern about my problem.

    I hope to send you the HMC 807 Control Program.

    I test circuit as Below.  same is Eval-board schmatic.

    I'm doing test at low temperatures  HMC807 Vt voltage increases. And last frequency locking.

    Charge pump value is change. Voltage is increases. Why?

    Do you have any EVAL-Board? IF you have EVAL-Board, test low temperatures.

    and you same test at low temperatures.Tell me which results you have. 

    I want to send you the video I tested. Please let me know your email address.

    Thank you for always giving me your interest.

  • my  email address  519499708@qq.com   Are  you   sure   your  loop filter  is  right   .The  CP  and   5V both   connect   to   a    same  pin  of THs4031.you  can   seed  me   e  mail  to  :519499708@qq.com    or   mc1519@126.com