AD9523-1 setting with AD9523


Our customer used AD9523 before. But AD9523 NRND, they need to change to AD9523-1.

1. If they change to AD9523-1, do they need to modify the firmware or hardware?

2. AD9523-1 add VCO Divider M1 and M2 Coupling meanwhile add some register.
Could you share the data that difference between AD9523 and AD9523-2?

[edited by: Julian Chen at 6:50 AM (GMT 0) on 22 May 2020]
  • +1
    •  Analog Employees 
    on May 22, 2020 3:49 PM


    the AD9523-1 has a much better absolute rms time jitter than the AD9523. See table 10 in the AD9523-1 rev A data sheet and compare it against the table 11 in the AD9523 rev D data sheet.

    However, there are some differences between the two chips and the bottom line is that the AD9523-1 is not a drop in replacement of the AD9523.

    In the following, I list some important differences:

    - pin 69 becomes a 1.8V supply pin on the AD9523-1, while being NC in the other. This means the PCB layout must be changed.

    - the AD9523-1 has some additional blocks: R2 divider in the VCXO data path towards PLL2, the M2 divider in the PLL2 VCO output path

    - the AD9523-1 PLL2 VCO changed range. This means a different PLL2 configuration must be designed. Also, a different clock distribution setting must be selected

    - PLL2 VCO dividers have less available values, which also means a different clock distribution dividers setting must be selected

    - some bits that in the AD9523 were reserved have functionality in the AD9523-1

    - some settings of existing bits have now a new meaning. For example, bit 4 in register 0x19: On AD9523, when bit is 0: antibacklash period is forced to high, on AD9523-1, when bit is 0: the device automatically controls the antibacklash period