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1. Continuous time delta sigma moculator

Hi All, I have been working on CT-DS ADC. It is a single bit quantizer. From my understanding, say we take NRZ DAC in the feedback and we design the ADC for the DAC amplitude of 1 and DAC width of 1 such that the area of DAC is equal to 1. With the integrator say being 1/s and the sampling...
2. Analog design at Intel

Hi All, I wanted to pick some brain and get people's opinion on how is Intel as far as analog design goes? I mean, in terms of learning and growth. I am a recent college graduate and 've opportunity to join Intel and my area of interest in analog and mixed signal design field. I understand...
3. Help me with a program for plotting FFT in Matlab

Hi All, I am trying to quantize a sinusoid signal and then plot its FFT using matlab. I did the quantization as in the attached file and then took the FFT. If you see, the FFT is not quite convincing. I mean, not in terms of SNR/SFDR but if you see the bottom of the fft, it looks like it...
4. Help me fix my Matlab code for finding SQNR

HI All, I am trying to find SQNR using a matlab code i wrote. But i am not sure where am i mistaking as the result is not matching to the standard equation of SQNR = 6.02N + 1.76. attached is the matlab code. %% Define the input signal clc; clear; p=10; Nfft = 2^p; n = 0:1:Nfft-1; % taking...
5. How to model mismatch between M3/M4 pair from this figure

Hi, In the figure below, I want to model the mismatch in M3/M4 device. (like may be say Vt mismatch) I know how to do that for M1/M2, M3/M5 and M7/M8 pairs but how shell i do for M3/M4 pair. thanks
6. noise at the output - track and hold

noise at the output: HI all, I have a track and hold followed by a source follower buffer (on silicon) and i have been testing it and seeing the output on an oscilloscope. Attached in one of the outputs i see. It has input signal of 100MHz and sampling frequency is 20MHz ( it is sub-sampling...
7. T/H spectrum in spectrum analyzer

HI all, I have a small question which i am getting confused with, I am testing a track and hold (on silicon) and want to see the spectrum of output on a spectrum analyzer. But, unlike a sample and hold , the track portion of the output would end up messing things up , i guess. I feel that i...
8. FFT computation in matlab for a data captured from scope

FFT computation. Hi all, I have some question regarding FFT computation in matlab for a data captured from scope. The situation is explained below: I have a track and hold circuit ( in silicon) and i am testing is by giving some input frequency say Fin and sampling clock say Fs. ( it is...
9. Need a swtich in cadence.

HI all, I need to do some simulation where i want to see the transient condition of the circuit when a new connection is made after some time from the start of transient state. I mean, if i run trans. analysis for say 100ps , so i want to run the circuit for 40ps in its original state and make...
10. Career in analog and mixed signal design area

ic design career hi all, i am a fresh graduate , masters, from Oregon state University. I am a question as i am going to start my career as analog and mixed signal design engineer. I was wondering if it is good and advantageous to begin IC design career in a middle order company as opposed to...
11. perturbation projection vector (PPV)

perturbation projection vector hi all, i need to find the perturbation projection vector of a LC oscillator. Can someone tell me how can i find that. I know that i have to do some sort of simulation in spice but what exactly do i have to do? thanks much.
12. generate jittery sine,square wave same amount of jitter

hi thanks for reply. I have one more question which is quite different from this. i want to generate the verilogA model for square wave and sine wave with jitter in both.Like same amount of random jitter in both. I tried looking designer's guide and i did get the square wave generation with...
13. Few clarification on SNR/SNDR calculation

snr calculation HI all, I need some clarification on calculating SNR/SNDR. I did cadence simulation of a sample and hold circuit and then took the FFT of the output. ( i did that keeping in mind the proper method of dealing sample data FFTs) now i want to calculate the SNR/SNDR and i want to...
14. jitter injectino in sinewave in cadence

hi all, I need to use sine wave with some known jitter in one of my research topic. I am using cadence for simulation and i used vsin for generating sine wave but there is no option of adding jitter to it. Is there any way i can ass jitter to the sine wave i get form 'analogLib' vsin cell? Or...
15. sine wave as Sampling clock

HI all, I am trying to explore the effect of using sine wave clock from sampling instead of conventional square wave. I understand that the major problem will be due to slow rise time of sine wave as compared to square wave but at high frequency sine wave still has sufficiently good rise time...
16. subsampling clock frequency condition to avoid aliasing

subsampling a signal HI All I am little new on subsampling so need some help.I have to subsample the VCO output, what should be the condition on subsampling clock frequency to avoid aliasing. From my knowledge, if the input signal is a multiple of sampling clock , it will result in...
17. some FFT clarification

HI Need some clarification on fft computation. Say, in the signal which has noise, i am interested only in a single frequency which is not the fundamental but is very close to fundamental, so can i ease down my fft computation overhead. Like reduce the sampling rate and N for fft and see the...
18. How to find the 2047 point FFT from a Simulink plot output?

hi every one... I am a student and am new to matlab.I have a plot output form the simulink and want to find its 2048 point fft with 10X over sample and 1GHz sampling rate. Please let know what steps i need to follow so as i can use the plot directly to get the fft. thanks and looking for reply.