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Some questions about SpectreRF and sampled circuits (Read 734 times)
ZY He
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Some questions about SpectreRF and sampled circuits
Jan 02nd, 2019, 10:55pm
 
Hey, recently i'm simulating some sampled circuits like sample and hold, and dynamic comparators.

i read some files and know sh can be simulated by spectreRF. i want to know whether it is proper to use SpectreRF to simulate dynamic comparators.

In other words, i want to know whether all the clocked circuits can use spectreRF to simulate their ac and noise performance.

i'm a newbie for SpectreRF. Thanks very much.  ;)
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Ken Kundert
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Re: Some questions about SpectreRF and sampled circuits
Reply #1 - Jan 2nd, 2019, 11:33pm
 
The basic assumptions of the RF analyses are that:
1. the circuit exhibits a meaningful periodic steady state solution, and
2. the circuit exhibits a small signal response to a small signal stimulus,
then the RF analyses are valid and useful.

So if you can put the dynamic comparator in a state where the clock is applied,
the input is zero, the resulting output is balanced between high and low, and
all the signals in the circuit are periodic, then you should be able to do
a small signal noise analysis and get useful information.

I have not done it myself and it may not be easy to put the circuit in the
needed state, but if you can, then PSS & PNoise should give you useful
predictions.

-Ken
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ZY He
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Re: Some questions about SpectreRF and sampled circuits
Reply #2 - Jan 2nd, 2019, 11:58pm
 
Thank you very much!

i realize maybe i asked a very weird question.

a dynamic comparator is not a 'real' sampled circuit. it outputs a digital signal no matter what kinds of input signals.
So i just need to simulate it by trans analysis.   Cheesy

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Andrew Beckett
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Re: Some questions about SpectreRF and sampled circuits
Reply #3 - Jan 6th, 2019, 3:34am
 
This ADC Verification Workshop (a Cadence Rapid Adoption Kit) has sections specifically on how to simulate a dynamic comparator using SpectreRF analyses, building upon the paper on this site on Comparator Metastability Analysis.

I know there's an updated version of this workshop in the works but it hasn't yet made it onto the Cadence support site.

Regards,

Andrew
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ZY He
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Re: Some questions about SpectreRF and sampled circuits
Reply #4 - Jan 11th, 2019, 6:50pm
 
Thank you very much!

These files really help me a lot.

Regards,

-ZY
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