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TSW1400+DAC5681 to generate a sweep frequency signal, from the 150M-250M

I would like to use TSW1400+DAC5681 to generate a sweep frequency signal, from the 150M-250M. scan time of 8 Microsecond, triggered by an external pulse signal.

I would like to confirm that an external pulse signal, triggering a sweep frequency, the initial phase of each sweep is the same? 8 Microsecond sweep frequency signal, the rate of 1G output, a total of 8K points, the linearity of its frequency can be guaranteed?
  • Hi,

    The TSW1400+DAC normally operates in a pattern generation loop mode and it will play back any pattern in its memory.  In this case you would need to generate this pattern externally and load this into the TSW1400 memory and then tell the TSW1400 to start playback by clicking the Send button in the HSDC Pro GUI.  The TSW1400 does not have a frequency sweep generation mode - this type of pattern needs to be provided from the user, the DAC will playback whatever pattern is provided.

    The TSW1400 will generate a pulse every time it loops the pattern on one of its SYNC SMA outputs (users guide describes this).  This can be used to trigger some external piece of equipment.  At a data rate of 1Gsps, 8k samples this will result in pulses at 8us periods.  Will this be adequate for your needs?

    There is also a mode in the TSW1400 that takes an input trigger pulse to play back the buffer, however this mode has not been tested thoroughly and is not documented in the users guide.  We will test this mode and update this thread once that has been confirmed.

    Ken.

  •      I need to trigger the cycle is 4 milliseconds, the time of the sweep frequency within each cycle is 8 microsecond(duty cycle 2%). I need to enter the file format and data format examples. Could you give me a sample file?

  • Hi,

    In that case you could generate a 4ms pattern with all 0 except the 8us of your pulse. You could then playback this signal and it will loop at 4ms period with an 8us burst. The sync will also output a pulse at every 4 ms to drive any external equipment. For formatting you just need have a txt file with integer values from -32768...+32767 representing the scale from -1 to +1 amplitude of your signal. For example for a ramp from -1 to +1 with 1 bit increment, you would have a file similar to:

    -32768
    -32766
    -32765
    ...
    -2
    -1
    0
    1
    2
    ...
    32767

    Ken.