AnsweredAssumed Answered

ADF4350 sweep problem?

Question asked by Peja on Aug 16, 2011
Latest reply on Aug 17, 2011 by Peja
Hello,
I have some issues  with sweep mode. ADF4350 is controlled by LPC22xx microprocessor. For example, i am trying to generate  
sweep signal 1000-1000.4 MHz, with channel spacing 200kHz, and delay 1uS (So basically i expect 3 frequencies 1000, 1000.2 and 1000.4).
What is the right sequency for writting to registers of ADF4350?
I tried with following without success:
1.    Write to REG_5    (0x00000005)
LE_UPDATE;                                                  // (LE==Load enbale, goes to 1)  optional delay after LE_enable
2.   Write to REG_4    (0x00AC803C)
LE_UPDATE;
3.  Write to REG_3    (0x000004B3)
LE_UPDATE;
4.  Write to REG_2    (0x00004EC2)
LE_UPDATE;
... end then....
5. write to REG1      (1000 MHz)   (0x080081F1)
LE_UPDATE;
  Write to REG_0        (1000 MHz)   (0x00500000)
LE_UPDATE;
6. write to REG1      (1000.2 MHz)  (0x080083E9)
LE_UPDATE;
  Write to REG_0        (1000.2 MHz)  (0x00500020)
LE_UPDATE;
7. write to REG1      (1000.4 MHz)
LE_UPDATE;
  Write to REG_0        (1000.4 MHz)
LE_UPDATE;
I guess  problem lies in load enable updates in 5., 6. and 7. (sequence is probably an issue)
Could anyone could tell me what is wrong and what is correct order of writting to Regs?
Best regards.
I have forgotten to mention that steps 5,6 and 7 are in endless loop.  (while)
Spectrum is extremly polluted, no resemblace with spectrum obtained with Eval Software....

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