Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

data conversion HSMC: max. DAC sampling rate?

Hi,

I'm trying to use the DAC (on the Stratix III DSP Kit) with a sampling rate of 240MHz, but the signals at the chip are very bad and it seems that the DAC samples the data incorrectly and thus the output is wrong.

I have been experimenting with different phases for the DAC clock (to increase the setup time) and different current strength and slew rate settings, but without success.

It seems to me that the board is not well designed (no termination, ..).

Has anybody successfully used the DAC with high (> 100MHz) frequencys?

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    You may try this simple test first(to exclude your data being the cause):

    inject two alternating + values directly at 240MHz and check that you get correct output (e.g. two lines spectrum at +120MHz).

    I will take it that your data is at 240MHz(sample rate)