THS5671A: output comes with more distortion

vetrivel M

Part Number: THS5671A

For testing the dac we are giving sin wave input (3mhz) and the sampling clock 46mhz from fpga. The input is exactly sin wave we have checked in matlab. We connected the mode pin to ground, so we are giving inputs as offset binary only. But the dac output comes with more distortion. How to overcome this?. For the reference I have attached the schematic, and output near IOUT1 and IOUT2. dac_schematic IOUT1 Iout2

over 2 years ago

0 Rob Reeder over 2 years ago

TI__Mastermind 37960 points

Hi Vetrivel,

Can you please post the PDF of the schematic? The snapshot schematic provided is difficult to read.

Can you please disconnect the rest of the output circuitry and then re-take the IOUT1/2 measurement?

Regards,

Rob

0 vetrivel M over 2 years ago in reply to Rob Reeder

Prodigy 150 points

Hi jim,

please find the attached.8764.DAC_schematic.pdf

0 Rob Reeder over 2 years ago in reply to vetrivel M

TI__Mastermind 37960 points

Thanks Vetrivel,

Did you try my suggestion above and try re-measuring the DAC outputs?

Thanks,

Rob

0 vetrivel M over 2 years ago in reply to Rob Reeder

Prodigy 150 points

Hi jim,

Sorry for late response. I'll update the details tomorrow.

Thanks,

Vetrivel

0 Rob Reeder over 2 years ago in reply to vetrivel M

TI__Mastermind 37960 points

ok, no problem.

Thx,

Rob

0 vetrivel M over 2 years ago in reply to Rob Reeder

Prodigy 150 points

Hi Rob,

sorry for this much late response. we tried your suggestion also we didn't get any improvement. then we added 0.1nF capacitor across the DAC output line to smooth the waveform. then we are able to get the smooth sine wave for 1Mhz output. but for 5.75Mhz, the output looks sawtooth wave. may i know why it is happening like this. for your reference i have attached the output waveform images of 1Mhz and 5.75Mhz.