Max Current Draw Differences in AD9081/2 Datasheet vs User Guide (UG-1578)?


I was looking at the datasheets for the AD9081/2 (Rev 0 and Rev B respectively) and the user guide (UG-1578, RevC) and noticed a few differences in the Max Current Draw numbers. The attached image shows the AD9081 (left), AD9082 (middle), and user guide (right) with red boxes showing some places the user guide's estimated max current numbers exceeding the AD9081/2's datasheet ones.

I had a couple questions from this

1. Are the A9081/2's max current draws in their datasheets only specced for JESD204C and the specific mode of operation called out in the datasheet? If so, is there a place where I can find the absolute max current draw of the converter's rails no matter the mode of operation?

2. Which device does the user guide's Table 108 (the one pictured) correspond to? The AD9081 or AD9082?

  • 0
    •  Analog Employees 
    on May 17, 2021 2:30 PM


    Answer to your questions are as follows:
    1) Power dissipation is dependent on the DAC and ADC clock rate as well as digital modes of operation.  The data presented in the datasheet are just for high bandwidth applications where all 8 SERDES lanes are used to provide maximum throughput rate between the host and AD908x device.   The next UG1578 revision provides the power dissipation for a wider sampling of use cases that include higher interpolation/decimation factors and lower lane count/ SERDES throughput rate.

    2)  Both the AD9081 and AD9082 have near identical pinouts.  For the supply domains highlighted in your attachment.............these pins are common to both devices.

  • Thanks for the answer! I had a couple followup questions below

    1. When is the next UG1578 revision planned to be released?

    2. Since the estimated max currents for rails are higher in a different mode of operation like in the user guide vs datasheet, I'm not sure how much current to support for each rail in the worst case and if the mode listed in the datasheet is the highest power drawing mode. Is there a resource that lists out the max current draw I can expect for each rail no matter the mode of operation?