TSW3084EVM: Spurs with example setup

Izik

Part Number: TSW3084EVM
Other Parts Discussed in Thread: DAC3484

We are running the example setup section 3.4 in the user guide, using TSW3084 and TSW1406

Please see the attached picture with spurs at offset of n*1.228MHz. I'm guessing that it is related to the DAC CLK 1228.8MHz, but we cannot eliminate those spurs.

We tried shutting down every non essential function in the board including clock but no success

Please advise

5811.Presentation1.pptx

Thanks

over 3 years ago

0 Kang Hsia over 3 years ago

TI__Guru 66054 points

Hi Izik,

This looks like either a mis-configuration of the interpolation block or misconfiguration of the FRAME/OSTR for the FIFO pointers. Please check the following configuration guide to see if any of the FRAME/OSTR or NCO sync signals are being continuously triggered.

0 Izik over 3 years ago in reply to Kang Hsia

Expert 1545 points

I tried working without NCO and complex mixer, now the signal is located around 30MHz, but still same spurs.

I turned off the FIFO input sync source, and set the FIFO output sync source to SIF SYNC - no effect

I turned off the clock divider sync - no effect

Can you please send the configuration files for both boards so we can follow the exact setup?

Thanks

0 Kang Hsia over 3 years ago in reply to Izik

TI__Guru 66054 points

Hello,

The TSW3084 software GUI installer should have installed some working configuration files already. Could you please refer to the user’s guide directory below for detail?

https://www.ti.com/lit/zip/slac507

0 Izik over 3 years ago in reply to Kang Hsia

Expert 1545 points

This is exactly what we did

Used the configuration file dac3484_1228p8MHz_4XINT_NCO_30MHz_dual_sync_sources for the TSW3084 (from the clock dist. folder)

and WCMDA_TM1_ComplexIF30MHz_Fdata_307.2MHz for the TSW1406 board

0 Kang Hsia over 3 years ago in reply to Izik

TI__Guru 66054 points

This is being investigated offline. The spur is due to discontinuity is longer waveform playback by the TSW1406. TSW1400 is needed to play the full waveform.

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TSW3084EVM: Spurs with example setup