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AD9518 Calibration

Question asked by jnoirjean on May 7, 2015
Latest reply on May 7, 2015 by pkern


I’m using an AD9518-0 on my electronics board and now I’m facing some trouble to get the card “ready to serve” after an electrical reboot. In the FPGA connected to the AD9518-o(via SPI), I’m programming all the required settings right after the FPGA has booted. The only remaining issue is that I don’t manage do a VCO calibration(datasheet/p.33) after the initialisation. I’m doing this sequence:

  1. Configuration of all the registers (included PLLControl3 register/VCO cal nowbit = ‘1’)
  2. update registers
  3. wait 2 ms
  4. PLLControl3 register/VCO cal nowbit = ‘0’
  5. update registers
  6. wait 2 ms
  7. PLLControl3 register/VCO cal nowbit = ‘1’
  8. update registers

After this sequence the bit Digital lock detect stays low(PLL readback register/b0) and the output frequency is out of bound. This obviously means that the VCO is not calibrated. However if I launched again this sequence manually, it works.

So my question is :

Is there a certain time to wait before doing a calibration after a power-up? If yes how long?