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Mar 28th, 2024, 1:39pm
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Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold (Read 992 times)
repah
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Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Mar 28th, 2020, 5:05pm
 
What is the difference between the Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold Amplifier ?

Is Bandwidth in tracking mode different then the sampling bandwidth ?

How would I find these using Cadence Spectre simulation ?
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Ken Kundert
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Re:  Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Reply #1 - Mar 29th, 2020, 12:36pm
 
To measure the sample bandwidth, use a PXF analysis where you sweep the output frequency from 0 to fs/2. Set max sidebands to something large, say 20-100. Run the analysis and plot the results including all sidebands by using the spectrum mode in direct plot. You can measure the sample bandwidth from the envelope of all the transfer functions.

To measure the bandwidth in track mode, simply turn off the clock and run an AC analysis.

-Ken
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repah
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Re:  Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Reply #2 - Apr 6th, 2020, 3:49pm
 
Hello Ken,

Thank you for responding.

Just to clarify - when you say turn clocks off - in AC analysis - if it was a Transmission gate - put the NMOS to VDD and the PMOS to GND and if a NMOS switch - NMOS high to VDD

Thank you.
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Ken Kundert
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Re:  Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Reply #3 - Apr 6th, 2020, 5:47pm
 
Yes.  Not a very useful measurement, but that is how you would make it.
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