in  my design I use the AD9525 only as clock distributor. In this configuration the REFA, REFB and REFC inputs are not used.

These pins are floating in my design. Is it correct?

The CP and CP_RSET are also floating. Is it always correct?

Thanks in advance.


  • 0
    •  Analog Employees 
    on Jun 14, 2021 1:13 PM


    yes, you can leave them floating.

    Some pins like 15 and 19 are ground pins for charge pump and PLL power supplies. Do connect them to ground.

    Supply all the VDD pins even if they belong to blocks that you do not use and will power down in software as below:

    To power down the related circuits in the configuration registers:

    - set bits 3:2 in register 0x10 to 10 to power down the charge pump

    - clear bit 7 in register 0x16 to 0 to disable REFC path

    - clear bits 7:4 in register 0x1A to 0 to disable various reference monitors

    - clear register 0x1C to 0 to power down some PLL blocks