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Nov 21st, 2019, 7:31pm
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The time in log file doesn't change while simulation is still running. (Read 4 times)
Leila Sharifi
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The time in log file doesn't change while simulation is still running.
Nov 09th, 2019, 1:22am
 
Hi,

I am simulating a second-order delta-sigma modulator.
my problem is that the simulation suddenly stops without reporting an error. in fact, simulation is still running but the time in log file doesn't change (even after several days!).

The sampling frequency is 2 MHz. I am going to simulate a 4096-point FFT. So I applied an input at the frequency of ((11*2 MHz)/4096).
the maxstep and minstep are set to 10n and 0.1p respectively.

when I reduce the number of FFT points, I don't face this problem. but to have an accurate FFT, I need to simulate it with more points.
for more information, I am using ideal switches in the circuit with Ron=1.5k and Roff=1G.

Could someone guide me for the same, please?

Thank you.
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Ken Kundert
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Re: The time in log file doesn't change while simulation is still running.
Reply #1 - Nov 10th, 2019, 8:56pm
 
How ideal are the switches?  My experience is that you are usually better off using mos0 transistors to model switches than trying to use idealized switches with switched-capacitor circuits.

-Ken
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