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Original question:

ADS7067: Datasheet Information on Acquisition time

ADS7067: Data acquisition time vs sampling speed

Yoel Sebbag
Prodigy 10 points
Part Number: ADS7067

Tool/software:

Hi all,

I am working with an ADS7067 ADC and wondered if the acquisition time changes with sampling speed.

When looking at the datasheet the minimum acquisition time is 300 ns, and the conversion time is 950 ns, this gives a 1.25 us cycle time (which corresponds to 800ksps).

However, the maximum allowable rate is 666.67 ksps, with 1.5 us cycle time.

What is the acquisition time for the configuration?

And if I lower the sampling rate to 500 ksps, what is the acquisition time?

Thank you!

  • +1
    TI__Expert 4130 points

    Hello Yoel! 

    Thank you for posting on TI's E2E forum! 

    Just to confirm with you, you are referring to "Table 6-3 Configuring Sampling Rate for Internal Conversion Start Control" when you mention the maximum allowable rate of 666.67kSPS and 1.5us cycle time, correct? Are you currently using the averaging module in this device?

    The Table 6-3 refers to modes where the the internal oscillator initiates the conversations, like when the averaging mode is enabled and the internal device makes N sample acquisitions before outputting a value. tAVG shown in Figure 6-3 explains the combined conversion and acquisition time for the N amount of samples set. 

    The conversion time, tCONV is independent of these configurations, typically the rest of the cycle time will be for acquiring the N+1 sample. 

    So for example, if in the sampling rate of 500kSPS, the acquisition will be about 2us-950ns. 

    Best regards, 

    Yolanda

  • 0 in reply to Yolanda Gonzalez
    Prodigy 10 points

    Hello Yolanda,

    Thank you for your quick and detailed answer.

    Yes, I was referring to the averaging module.

    Best regards.