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Simulators >> Circuit Simulators >> Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
https://designers-guide.org/forum/YaBB.pl?num=1585440322

Message started by repah on Mar 28^th, 2020, 5:05pm

Title: Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Post by repah on Mar 28^th, 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 ?

Title: Re: Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Post by Ken Kundert on Mar 29^th, 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

Title: Re: Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Post by repah on Apr 6^th, 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.

Title: Re: Sampling Bandwidth vs. Bandwidth in Tracking Mode of a Sample/Track and Hold
Post by Ken Kundert on Apr 6^th, 2020, 5:47pm

Yes. Not a very useful measurement, but that is how you would make it.