Post Go back to editing

FMCDAQ2: Square wave with DAC buffer output

Dear Technical Support Team,

I use FMCDAQ2 and VC707(Xilinx Virtex-7).

I'd like to make a square wave(20MHz/1Vpp) with DAC buffer output of IIO  Oscilloscope tool.

There is some sample design following folder.

C:\Program Files\IIO Oscilloscope\lib\osc\waveforms

For example,11.txt includes all "1" for dac output. 

What the meaning of the "1"? Dose it mean 1V?

Also, the sampling rate of the DAC seems to be fixed at 1Gbps (1ns).

When generating a 20MHz (50ns) square wave with text file, is it correct to describe it with 25 points plus(500mV) + 25 points minus(-500mV)  (total 50 points = 50ns)?

If you load the DAC output settings and generate a square wave of s) in text, is it correct to describe it with 25 points + 25 points (total 50 points = 50ns)?

If you have a sample text file of square wave (20MHz, 1Vpp) to be loaded in the DAC buffer output, it would be helpful if you could send it.

Best Regard

ttd



Add board infomation
[edited by: ttd at 6:04 AM (GMT -5) on 4 Feb 2022]

Top Replies

    •  Analog Employees 
    Feb 11, 2022 in reply to ttd +1 verified

    Hello,

    Here is a link where you can find more information related to the data format. Our solution proposes to describe the square signal with 25 points with the value 1 and 25 points with the value …

Parents
  • Hi,

    I got 20MHz square wave with DAC Buffer output. However, it has some noise on rise and fall edge.

    These are Pch and Nch waveform of AD9144(DAC).
    Transformer is bypassed and monitored them.

    How do I improve it? 
    If you have some workaround about IIO Oscilloscope settings, could you share it?

    It seems to be fixed 1GSPS(1ns). Is it setting for 2.8Gbps(MAX)? 

    ■With Transformer on FMCDAQ2

    ■Without Transformer on FMCDAQ2 ⇒ Pch and Nch of DAC output waveform

    TEXT
    0	0
    125	125
    250	250
    375	375
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    375	375
    250	250
    125	125
    0	0
    -125	-125
    -250	-250
    -375	-375
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -375	-375
    -250	-250
    -125	-125
    

    Best Regards,

    ttd

Reply
  • Hi,

    I got 20MHz square wave with DAC Buffer output. However, it has some noise on rise and fall edge.

    These are Pch and Nch waveform of AD9144(DAC).
    Transformer is bypassed and monitored them.

    How do I improve it? 
    If you have some workaround about IIO Oscilloscope settings, could you share it?

    It seems to be fixed 1GSPS(1ns). Is it setting for 2.8Gbps(MAX)? 

    ■With Transformer on FMCDAQ2

    ■Without Transformer on FMCDAQ2 ⇒ Pch and Nch of DAC output waveform

    TEXT
    0	0
    125	125
    250	250
    375	375
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    500	500
    375	375
    250	250
    125	125
    0	0
    -125	-125
    -250	-250
    -375	-375
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -500	-500
    -375	-375
    -250	-250
    -125	-125
    

    Best Regards,

    ttd

Children
  • Hello,

    Here is a link where you can find more information related to the data format. Our solution proposes to describe the square signal with 25 points with the value 1 and 25 points with the value -1 and use the appropriate scale attenuation value in order to obtain the desired amplitude voltage.