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DAC38J82EVM: Use of thei EVM in Lower frequency application

wijempa
Prodigy 20 points
Part Number: DAC38J82EVM

Tool/software:

Hi

We are planing to use this EVM in an application that require outputting DC to 500MHz sine-waves (and other waves such as square). However the EVM outputs are high pass filtered based on the user guide so any frequency below 10MHz are cut off. Based on the schematic this high pass filtering seem to be enforced through two RF transformers T1-T8 for 4 channels. Much of the other components in the  output path are resistors. Could I know whether we can operate it from 0-500MHz if we remove these transformers and solder 0ohm resistors to connect inputs/outputs as below?

Also, we wish to configure both DAC and Clock IC's through a micro-controller. I hope we can use J24 to select FMC as the SPI signal source and then use J24 and J25 to connect the micro-controller SPI pins? 

Thanks

  • 0
    TI__Intellectual 2660 points

    Hello, 

    Our Devices typically have baluns on the output to convert the differential output of the DAC into a single ended signal. This helps with the even order distortion of the DAC. There are inherently AC-coupled. There are ways to DC couple the output of the DAC. Here is some errata on how that could be done with a DAC with a very similar pull up current source output state. 

    www.ti.com/.../slua647a.pdf

    This board has a large CPLD on it that we don't have the source for the firmware for anymore. I have not tested the FMC communication on this board using that approach. Unfortunately we cannot officially support this but in theory it could work. 

    Regards, 

    Matt