ADC16DV160: ADC16DV160\IF input noise

Esakki Durai

Part Number: ADC16DV160

Tool/software:

Dear Team,

We are using the ADC part (ADC16DV160) in our design at Fin=70MHz and the sampling frequency Fs=160MHz.

We have connected the Fin from signal generator to ADC16DV160 ADC and Spectrum Analyzer through power Divider as per image.

In this case we are facing some spurs in our spectrum as per the attached image.

Observed spurs Frequency : FS+Fin = 230MHz, Fs-Fin = 90MHz,2Fs+Fin = 390MHz & 2Fs-Fin = 250MHz.

Can you please suggest the reason for this source of the spur?
Any app note explain this effect on ADC?
Whether spurs observed in spectrum will affect my ADC performance?

Regards,
Esakki.

6 months ago

0 Esakki Durai 6 months ago

Prodigy 160 points

0 Esakki Durai 6 months ago

Prodigy 160 points

0 Rob Reeder 6 months ago in reply to Esakki Durai

TI__Mastermind 39310 points

Hi Esakki,

The spurious is coming from the signal generator. Please use a bandpass filter on the output of the sig gen, I would connect it close to the EVM.

Setup should be as follows: Sig gen-cable-BPfilter-EVM

If you need a reference for testing HSADCs, please see link: https://www.analog.com/media/en/technical-documentation/app-notes/an-835.pdf

Page 11.

Regards,

Rob

0 Esakki Durai 6 months ago in reply to Rob Reeder

Prodigy 160 points

Hi rob,

Thanks for your feedback. We checked by connecting Bandpass filter between signal generator and power divider also. Power levels for input frequency harmonic only reduced.

Observed spurs Frequency : FS+Fin = 230MHz, Fs-Fin = 90MHz,2Fs+Fin = 390MHz & 2Fs-Fin = 250MHz not getting changed.

Can you test and share the data in your evaluation module?

Clarify the spur generating in unbuffered adc regarding Fs+fin & Fs-fin?

Regards,
Esakki.

0 Rob Reeder 6 months ago in reply to Esakki Durai

TI__Mastermind 39310 points

Hi Esakki,

Please see figure 20 on page 14 of the datasheet. This is a 70MHz analog input.

Please remove the power splitter and extra cabling.

What bandpass filter did you use? Part number?

What signal generator model number is being used for the analog input?

What signal generator model number is being use for the clock input?

Regards,

Rob

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ADC16DV160: ADC16DV160\IF input noise