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12th September 2007, 06:52 #1
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sdadc .mdl
i have read the allen's book about the ad/da.So i want to design the circuit and simulation for it.but i donnt know how to start.the software i know is cadence and matlab.and i know use the veriloga to design the DAC and the verilog to decimator and filter.But i am not sure.
Also,can anyone tell me the procedure in detail？
Added after 1 hours 1 minutes:
e.g i have made the schematic for integral,quantizer and veriloga for DAC.how to connect them and simulate. and can veriloga describe the quantizer or other?can anybody reply?

12th September 2007, 08:57 #2
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veriloga adc delta sigma
Originally Posted by CISSE
Matlab & Spectre are enough, I think.
U need to know the zdomain model about SDM at first.
And begin from the simplest structure is a good choice. Such as a 2nd Order SDM.
We usually realize the zdomain model by switch capacitor structure because the inverting/noninverting SC integrator can get discrete transfunctions, what is the same SDM required.
Added after 2 minutes:
after u understand the zdomain model, u'll know why the noise can be shaping.
and, the zdomain model is ideal. many nonideal effect need to be simulate at Matlab.

28th September 2007, 04:19 #3
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delsig adc
thanks,YUANHUI
my understanding about SDM is that the STF and NTF is not the same because the path they cross is different.So the signal is just delayed and the inband noise is supressed.
the simulation about SDM in spectre at transistor level is too slow.but i'm not good at matlab.can you tell me how to simulate the ideal and more accurate model od SDM?
and i dont know how to simulate the whole ADC.i mean including the verilog of digitalfilter and veriloga of DAC.i can do it in the spectre.dose it need some additional license or is there any tools? the fast one is better.

28th September 2007, 04:19

1st October 2007, 08:00 #4
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how to work with delsig tool in matlab
u just use Matlab Similink tool to model ur ADC and u can calculate requred SNR and ENOB. it will helpfull to simulate complete model of ADC with Matlab. tool are available at Mathworks.com

11th October 2007, 09:19 #5
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sdtoolbox
Originally Posted by shiveshdubey
i just can make the model in simulink,but i know little about the toolbox. i even dont know the procedure about the simulation.can you tell me more detail?

11th October 2007, 10:37 #6
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simulink dspsdadc
Hi, u just see the Matlab simulink toolbox.there is block available to model ur design like integrator, quantizer, filter and etc.u can use these block to model ur design.

12th October 2007, 04:13 #7
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murmann spectre
i have added blocks in my model.but i can change the parameters of the CIC Decimation bolck and FIR Decimation block.e.g.i want to change the Decimation factor (R) of CIC block. maybe somethings should be installed.but i dont know in detail.

15th October 2007, 09:16 #8
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murmann sc noise spectre
i followed the simulink demo'dspsdadc' in R14 and try to modify the first FIR Decimation to CIC Decimation.some errors was reported when i started the simultion.but i have no idea about it.
And i think this model is different from what i‘ve designed.my intergal is SC but that is continuous.Also i cannot find out the SC block.And my Fs=256*Fn,So i need the CIC Decimation.but i can't use the CIC What i've mentioned above.
So,if someone have made the simulink work of SDADC before,please help me.

15th October 2007, 09:16

16th October 2007, 08:20 #9
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simulink model for sdm adc
OK.finally,i give up the demo.i download the toolbox from mathworks.there are two toolboxs,delsig and SDtoolbox.it's easy to use the SDtoolbox by adding the path.but i have trouble in delsig.i type the 'delsig' at the Matlab prompt but it dosen't work.
Added after 1 hours 9 minutes:
maybe the delsig cant give the graphic block what SDtoolbox can in the simulink.just open the *.m and simlution it.am i right?

16th October 2007, 08:20

16th October 2007, 09:52 #10
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cic spectre pdf
Originally Posted by CISSE

16th October 2007, 10:38 #11
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delsig mathworks
Hi,
The link is the Homework projects on Murmann's slides in his classes and could be useful. They are related with data converters. They will help you in your procedure of learning and designing DS ADC and will give you a deep insight through ADC design..
Here is the link:
http://eeclass.stanford.edu/cgibin/...e315reader.pdf

17th October 2007, 03:19 #12
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simulatedsm function in delsig
thaks,naalald
hi,shiveshdubey
did you calculate the clockjitter's formula which is label(1) in his IEEE paper?i think the part of 'cos' is cos[pi*f(2t+delta)],not cos(2*pi*f*t).maybe it can be equal approximately but i dont know the reason.

17th October 2007, 03:24 #13
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Re: how to design delta sigma ADC
this one is useful
Originally Posted by naalald

17th October 2007, 05:44 #14
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Re: how to design delta sigma ADC
Originally Posted by CISSE

17th October 2007, 08:17 #15
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Re: how to design delta sigma ADC
i can't understand your meaning clearly.
my understanding about the formula(1)

17th October 2007, 08:25 #16
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Re: how to design delta sigma ADC
is that

17th October 2007, 08:25

17th October 2007, 09:05 #17
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Re: how to design delta sigma ADC
and then,sin(x)=x if x is very little.but i can't understand why the part of cos() is equal.
Added after 36 minutes:
the second question is what's the difference between discrete integrator without and with delay.i just know the one without delay.

18th October 2007, 09:25 #18
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Re: how to design delta sigma ADC
i am studying the SD2mod.mdl of the SDtoolbox.the third question is the ADCDAC block.what's DAClevelREAL and the selector after it?please tell me if someone knows.

30th November 2007, 11:13 #19
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Re: how to design delta sigma ADC
this is included demo for you.
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