DAC38RF82EVM: DAC38RF82EVM and TSW14J57EVM:LMF=821,fail to generate square square wave as requested,fail to synchronize between two DACs as well

xqy22

Part Number: DAC38RF82EVM
Other Parts Discussed in Thread: DAC38RF82, TSW14J57EVM

Hi everyone,

My intended application is to generate two synchronized waveforms through the DAC38RF82EVM 's two channels.To do this I load a 100kHz sine wave to channel 1 and a square wave with 50% duty cycle to channel 2 in HSDC Pro.Below are the two waveforms in csv form and my HSDC Pro and DAC GUI configuration screenshots.

sintest.csv

DAC38RF82_6144M_config.pptx

The DAC38RF82 I use works in dual dac mode with real inputs LMF=821 while using the onboard VCXO (CMODE4). I started with an example cfg file from another post,

7181.6144MSPS_8x_10M_ref_LMF_841.cfg

then changed the configurations in the DAC GUI quick start page, and follow the instructions in that thread of loading another cfg file using the low level tab instead of clicking on the "Reset DAC and JESD Core & SYSREF Trigger".

7181.GUI reset no LMK.cfg

But the output results are really weird.The square wave did not turn up as expected and the two channels were not phase aligned.

I haven't used any DAC evaluation boards before, so I'm not sure what's wrong.

I will appreciate any help,thanks!

over 1 year ago

0 Chase W over 1 year ago

TI__Mastermind 22680 points

After the config is loaded, have you pressed issue sysref and then also the reset jesd core buttons on the first page?

Thanks

0 xqy22 over 1 year ago in reply to Chase W

Prodigy 20 points

Hi Chase,

No,I followed the instructions of Jim in this thread

https://e2e.ti.com/support/data-converters-group/data-converters/f/data-converters-forum/962806/dac38rf82evm-dual-dac-real-mode-4x-interpolation-lmf-821-synchronization-between-dacs

so after the config was loaded I did not press issue sysref and reset jesd core button on the first page, instead i loaded another config file given by Jim in the thread.

However I also tried to press the button after I load the config, and the results were the same.

Thanks

0 Chase W over 1 year ago in reply to xqy22

TI__Mastermind 22680 points

Hi,

The TSW14J57EVM does not support trigger function for DAC mode, only ADC. I can suggest to follow this thread for getting alternative method to trigger.

Regarding the DAC configuration, can you provide the first page of the DAC38RFxx gui in your desired configuration? I can create and test a configuration for you.

Thanks, Chase

0 xqy22 over 1 year ago in reply to Chase W

Prodigy 20 points

Hi Chase,

thanks for the reply! Yes I can give you my configurations and it will be awesome if you are willing to try, thanks a lot for that!

Here's the first page of the GUI and also the csv file I used:

and my csv file:

8103.sintest.csv

channel 1 is a 100KHz sine wave and channel 2 is a 50% duty cycle square wave,both waves last 1ms, sample rate is 1.536GHz.

Thank you so much again!

0 Chase W over 1 year ago in reply to xqy22

TI__Mastermind 22680 points

Hi,

Sorry for the long delay. Attached is configuration file which achieves 6144MSPS, Dual DAC real input, 4x interpolation, and accepts a 10MHz reference into J4. Ensure that JP10 is removed and that JP3 is connected. After loading this configuration file, download the firmware into the FPGA using HSDC Pro and send data. After data is being transmitted, press the Reset DAC & SYSREF Trigger button.

DAC38RF82_82121_6144MSPS_4xInt_10MHz_J4.cfg

Thanks, Chase

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DAC38RF82EVM: DAC38RF82EVM and TSW14J57EVM:LMF=821,fail to generate square square wave as requested,fail to synchronize between two DACs as well