ADS41B49 + TSW1400

WhiteHorse

Other Parts Discussed in Thread: ADS41B49, ADS4149, ADS58B18

We have a customer using the ADS41B49 and TSW1400.

TSW1400 board connected to USB on computer and running 5V Wall port. Also connected directly to the ADS41B49 Eval board, which is being powered by an external 3.3V source (into the 3.3V and Ground jacks). Clock input to the ADS41B49 board (25MHz at +10dBm) into J19. Signal of interest (6MHz @ -40dBm) into J6 on the ADS41B49 board.

Seeing phenomena where the noise floor randomly gets about 30 – 50dB higher, then jumps back down. It seems to happen at random intervals between 20 and 50 seconds apart.. See attached word document.

2727.Problems with TI TSW1400 Board paired with ADS41B49 Eval Board.docx

Thanks for your help.

Regards,

John Wiemeyer

over 11 years ago

0 Ken C over 11 years ago

TI__Genius 12965 points

John,

Please have them select ADS4149 device in HSDC Pro GUI. The ADS58B18 as shown in the word file is not the same.

Ken.

0 WhiteHorse over 11 years ago in reply to Ken C

Genius 4430 points

Thanks Ken. I'll let you know how that works. Regards, John

0 WhiteHorse over 11 years ago in reply to WhiteHorse

Genius 4430 points

Hi Ken,

Customer says they have already tried that it didn’t make any different. They also changed the frequencies to see if it was related to the frequency being too low, and the problem still exists when using clock at 100MHz and signal at 75MHz

What else should we check?

Thanks,

John

0 Matt Guibord over 11 years ago in reply to WhiteHorse

TI__Genius 17320 points

Hi John,

Please have the customer send over the raw ADC codes for a good and a bad capture. In HSDCPro, go to File->Save as CSV File .

Regards,
Matt Guibord

0 WhiteHorse over 11 years ago in reply to Matt Guibord

Genius 4430 points

Hi Matt,

Got the data. Its attached. Thanks for your help!

Regards,

John

4532.ADS41B49_75Msignal_100Mclock_Data_040814.zip

0 Matt Guibord over 11 years ago in reply to WhiteHorse

TI__Genius 17320 points

Hi John,

This has already been answered separately through e-mail. The issue is that the ADC is current in 2's compliment mode because the DFS jumper is placed incorrectly. It needs to be moved to the "BIN, LVDS" setting.

Regards,
Matt Guibord

0 WhiteHorse over 11 years ago in reply to Matt Guibord

Genius 4430 points

HI Matt,

Didn't seet the email, but thanks for the jumper setting. I'll let the customer know.

Reagrds,

John

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ADS41B49 + TSW1400