What is acquisition time for Scan_ADC_v3_10?

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YoIs_1298666
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Hello,

I think that the acquisition time means below like the AN88619 of "PSoC® 4 Hardware Design Considerations".

pastedImage_5.png

but, "Achieved acquisition time" seems to depend on ADC clock rate and conversion time.

pastedImage_8.png

What does it mean?

and What does "Minimum acq. time" exist for?

Best regards,

Yocchi

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1 Solution
Vasanth
Moderator
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Hi Yocchi san,

Minimum acq. time (ns)

The user can enter a minimum acquisition time (in ns) that the input sampling process will dwell on this channel before actually making the conversion. The field is editable but is pre-populated with the shortest value currently possible with the system clock parameters.

Achieved acq. time (ns)

This display field shows the acquisition time (in ns) that the scheduler has selected. It is always equal to or higher (longer duration) than the user-requested value.

The minimum acquisition time ensures the half LSB accuracy you have posted. Where as the achieved acquisition time can vary according to your clock settings. The component makes sure that it is higher than the value we request it to be.

Best Regards,
Vasanth

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Vasanth
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Moderator
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250 sign-ins 500 solutions authored First question asked

Hi Yocchi san,

Minimum acq. time (ns)

The user can enter a minimum acquisition time (in ns) that the input sampling process will dwell on this channel before actually making the conversion. The field is editable but is pre-populated with the shortest value currently possible with the system clock parameters.

Achieved acq. time (ns)

This display field shows the acquisition time (in ns) that the scheduler has selected. It is always equal to or higher (longer duration) than the user-requested value.

The minimum acquisition time ensures the half LSB accuracy you have posted. Where as the achieved acquisition time can vary according to your clock settings. The component makes sure that it is higher than the value we request it to be.

Best Regards,
Vasanth

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Hello Vasanth-san,

OK.

I don't know why the acquisition time is influenced by the clock settings.

but, I can understand that the achieved acq.time(ns) is configured with both "Free-run scan rate(SPS)" and "Minimum acq.time(ns)" settings manually and the priority of "Minimum acq.time(ns)" setting is higher than one of "Free-run scan rate(SPS)" setting.

Is this correct?

pastedImage_1.pngpastedImage_2.png

Best regards,

Yocchi

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Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hello Yocchi san,

Yes understanding is right. You can adjust the achieved acquisition time with sample rate, till the value restricted by minimum acquisition time.

Best Regards,
Vasanth

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