Post Go back to editing

AD9576 PLL0 internal loop filter

Category: Datasheet/Specs
Product Number: AD9576

Is there a diagram available that can show the topology of the PLL0 loop filter when internal mode is selected identifying the 3 adjustable components? (RPOLE2, RZERO, CPOLE1 and fixed CPOLE2).

Also, the datasheet states to attach a 4.7nF capacitor between LF and LDO_BYP pins.  Does this capacitor also form part of the loop filter when internal mode is selected?

  • Hi,

    the AD9576 rev A data sheet states at page 32 that the 4.7nF capacitor between LF and LDO_BYP pins is part of the internal loop filter: 

    We do not have documentation to show how varying the 3 adjustable components of the internal loop filter influences the loop filter.

    I recommend to use the values that come up when you launch the AD9576 evaluation software:

    From what I see, only Rzero=3000ohm differs from the 3375ohm default value. Rpol2 and Cpol1 are set at default values.

    Petre