I'd like to evaluate the 'boost' mode on the ADF4150HV. The eval software that came with the eval board does not seem to support this register function. Is there new software available that allows the mode to be enabled?
If your evaluation board model ends in -U1 , i.e. "EVAL-ADF4150HVEB1Z-U1" , then the boost mode does not work correctly on
this version of silicon and is why it was omitted from the software that went with the board.
If you have the final silicon eval board model ending in -U2, then the boost mode operates correctly. I've attached the software that
comes with this version. You will have to rename this from .txt to .exe (done to allow you to download the file).
You should place this in C:\Program Files\Analog Devices\ADF4150HV . You will need to update the shortcuts also if you want
to run it from the Windows Programs menu.
We plan to release the ADF4150HV in the next few weeks.
Also, on page 9 of the ADF4150HV datasheet there is a plot showing boost lock time vs. 'normal' locktime (upper right). I can't decipher the x-axis -- I assume the ticks are increments of 50 uS?
Here is a better image of this plot. The plots will be tidied up in the Rev.0 version.
In the datasheet, the lock time with boost on mode, is ~100us (for a 100kHz loop BW).
If the loop BW is further increased, is it possible to bring down the lock time further?
Figure 8 & 9 gives information regarding the fractional spur levels. What is the loop BW under this condition?
Increasing loop bandwidth should reduce the lock time, but please ensure that the loop is stable with wider loop bandwidth - for too wide bandwidth the part might not lock. Increasing charge pump current to maximum (400 uA) for the time when the frequency is changed is another option to make loop filter bandwidth wider only for short period of time.
Figures 8 and 9 from teh datasheet were taken with loop filter bandwidth about 55 kHz. Please note that this is spur level measured directly on VCO output.
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