Other Parts Discussed in Thread: DAC37J84, LMK04828
Hi, TI
I’m working with DAC37J84+TSW14J10+ZC706. Following the instructions of TSW14J10 FMC-USB Interposer Card [SLAU580B] I successfully obtained a 10MHz tone on all outputs of DAC. But now I am trying to generate a pulsed 1MHz signal at the output of the DAC37J84EVM.
First I generated a file with the desired waveform for each channel, a pulsed 1 MHz signal in channel 1 and zero in the rest of the channels. Then, using "Load an external pattern file" button I loaded the file to the HSDC Pro Software. Finally, I send data to ZC706 using "Send" button. Attached I send a capture of HSDC Pro software after loading the pattern file.
After pressing "Reset DAC JESD Core" and "Trigger LMK04828 SYSREF" in DAC3xJ8x GUI v1.2 I get a signal at the output of the DAC that seems to be filtered by a high pass filter. Attached I send a screenshot of the oscilloscope.
First I thought it could be due to the fact that the outputs are transformer coupled, but when I tested with the oscilloscope probe before the transformers (specifically in R5 resistance, see figure attached) I got a signal with the same characteristics.
I would like to know what I’m doing wrong. Is there any internal configuration that could be performing an AC coupling or something like that?
Best regards,
