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https://designers-guide.org/forum/YaBB.pl Simulators >> Circuit Simulators >> can i do nyquist criterion in cadence https://designers-guide.org/forum/YaBB.pl?num=1256285271 Message started by cczhang on Oct 23rd, 2009, 1:07am |
Title: can i do nyquist criterion in cadence Post by cczhang on Oct 23rd, 2009, 1:07am hi i want to know can i do nyquist criterion in cadence. the version of cadence is ic5141. if it can be done, ple tell me how to do it. thanks very much and also i want to know how to start stb simulation in cadence. thanks zcc |
Title: Re: can i do nyquist criterion in cadence Post by buddypoor on Oct 23rd, 2009, 1:16am cczhang wrote on Oct 23rd, 2009, 1:07am:
Of course, you can. All you need is an ac analysis and the capability to draw the imaginary part of the loop gain vs. the real part. |
Title: Re: can i do nyquist criterion in cadence Post by cczhang on Oct 23rd, 2009, 1:39am Of course, you can. All you need is an ac analysis and the capability to draw the imaginary part of the loop gain vs. the real part. [/quote] hi ,could you explain more details how to use? thanks for example how can i get the trans function of loop gain and how can i draw the imaginary part of the loop gain vs. the real part? |
Title: Re: can i do nyquist criterion in cadence Post by buddypoor on Oct 23rd, 2009, 2:59am cczhang wrote on Oct 23rd, 2009, 1:39am:
I am afraid you are not very familiar with the subject - and therefore, itīs not easy to explain in detail the meaning resp. simulation alternatives for loop gain. I am not working with Cadence, but with a lot of other simulation programs - nevertheless I am sure that you can ask cadence to plot IM(L(s)) if L(s) is the loop gain. And than you can change the x-axis to show R(L(s)). And this gives you the NYQUIST plot. I repeat: At first you have to become familiar with the term loop gain - and how to simulate it. This item has been discussed very often in this forum. Regards + good luck. |
Title: Re: can i do nyquist criterion in cadence Post by cczhang on Oct 25th, 2009, 5:54pm thanks very much. |
Title: Re: can i do nyquist criterion in cadence Post by larry flowers on Oct 5th, 2012, 7:04am Hi If you just want results for some application purpose and this simulation is not specific to just cadence ; then i think you can do this better at MAT-LAB simmulink. Mat lab has built in function for Feedback loop gain. For 'gain' : It is the measure of ability of a system to increase its output (Power , Amplitude) with respect to Input. For 'Loop gain' : If this gain is controlled by some feed back then it is called loop gain. Remember adding Loop to some system decreases its overall gain. Nyquist Criterion : It tells whether the system under consideration is stable or not and if not stable what changes can be done to make it stable ! This is actually dealing with complex variables in terms of systems ;) and Plotting results. thanks |
Title: Re: can i do nyquist criterion in cadence Post by boe on Oct 5th, 2012, 9:32am larry flowers wrote on Oct 5th, 2012, 7:04am:
- B O E |
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