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High freq quantization noise means variation of signal after and before quantizer in time domain is higher and not signal is high freq.
After quantizer any way we have decimator and filter to cutt all higher freqs.
Your sim results are as expected. AC analysis doesnot kill dc sources, it will take dc points before calculating AC analysis data. You are not offsetting the opamp as you mentioned but giving common mode signal on dc 6V . Are u clear?
first thing is comparator and canb designed with low power consumption thats not a problem. Hyaterisis ll be around 50-20mv based on ur application. Ur trigger pt=1.3 so u can use nmos diffpair at input. U didnt mentioned del time in ur spec?
Re: op amp question
Its the senario u r using this ckt for digital or analog application. Certnly its output bufer stage bcoz of high sizes and CS config. Csink and source txs are having high Gm s if u see it .
I think PSRR- is not necessary and if u do it it shows very less, bcoz only R's in that sig path..
in case of source ,sink ldo which is capable of providing i in both dirs then psrr from + and PSRR- id=s very imp concerns.
Lambda varies with process ,device parameters and more. simualte simple fet Id ,Vds char and extend the I line to - axis of Vds ,the point it cuts gives u 1/Lamda.
Or if u have Gds of ur fet ,then Lamda=Gds/Id
Note that its different for diff. values of Id also
Re: hspice & spectre
Hi ,while running, simulator's algorithms are able to track fine values of V&I set in ur simulator ,its a iteration process ..genlly for the first cut simulator uses basic newtons Raphson method ..if convergence is not achieved it go for next advance algorithms.
Hi , max current is that ldo can supply and beyond this ldo's pass transistor may not able to get quiescent I it need for proper operation. So Rload shudnt fall below certain value,if that is the case ur Vo wont maintain at req value.
Re: opa for bandgap
Hi , actually u dont need to use 2nd stage and put cascode connection in the first stage in ut FC opamp. Then no need for compensation ,if o/p drives less cap load use load cap at o/p that plays compensation role so that u dont need any resistor now.