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How to design SAR ADC?

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batistuta

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ideal comparator model

hi,guys
i want to design a SAR ADC, but i don't know how to start, can anybody give me some advices? is there have some tutorial about this topic?
from a paper i see it's step by step: just as follows,

(((The first step of the process is generating
MATLAB code to algorithmically describe the ADC. In this
phase, information about general operation is extracted. The
second step is to generate a complete AHDL model of the
ADC. AHDL blocks such as D flip-flops, a non-clocked
comparator, a non-clocked DAC, and ideal voltage sources are
used in this phase. This model contains no timing information,
but rather verifies circuit functionality. Another benefit of this
phase is that different ADC architecture styles are tested with
little simulation time. At the end of this phase the architecture
of the developed ADC is known. In the third phase, a more
descriptive model of the ADC is built using all AHDL
components. This model uses similar components as the
previous model, however, they contain imperfections such as
rise times, fall times, delay times, finite gains, etc. This model
allows us to adjust these imperfections and observe how theyaffect the performance of the ADC with little simulation time.
For example, INL, DNL, and SNDR are simulated as
functions of these imperfections. Another benefit of this stage
is that all timing analysis is competed and verified. To help in
the designing of the real components typical values are entered
into this model. With the typical values in place we are able to
tweak and arrive at an ADC that meets specifications. This
model helps define the individual specifications for all of the
real components. In the fourth phase, AHDL components are
replaced with their real counterparts. The real components are
designed to the same specifications found in the previous
phase. The replacement process happens one by one. In other
words, one AHDL component is replaced in the AHDL model
and re-simulated. This allows for the testing of the real
components in a working setting. The fifth phase is to run a
completely real transistor level simulation, and verify through
extensive testing, that the SAR is realizable.)))

my question is :
1.when design a ADC, the step always like this? or other method?
2.should i master the MATLAB language and AHDL first? if so,how to start?
thanks.
baggio
 

mahgoub

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sar adc buffer

i think you are write about the model but if you are working with cadence
you have ideal elements that you can use without ahdl description
you can build your model using this ideal elements
for example
model for buffer and gain stage:
in cadence you will find an ideal differential buffer and an ideal comparator
and in some upgraded cadence you may find a digital library
that you can use in your model
so if running out of time donot use matlab

Added after 2 minutes:

i think you are write about the model but if you are working with cadence
you have ideal elements that you can use without ahdl description
you can build your model using this ideal elements
for example
model for buffer and gain stage:
in cadence you will find an ideal differential buffer and an ideal comparator
and in some upgraded cadence you may find a digital library
that you can use in your model
so if running out of time donot use matlab

Added after 22 seconds:

i think you are write about the model but if you are working with cadence
you have ideal elements that you can use without ahdl description
you can build your model using this ideal elements
for example
model for buffer and gain stage:
in cadence you will find an ideal differential buffer and an ideal comparator
and in some upgraded cadence you may find a digital library
that you can use in your model
so if running out of time donot use matlab
 

northeast1

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comparator for sar adc + cadence

reference to charpter 10 of P.E.Aellen
 

mickey_melomane

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design for adc

How do you simulate the INL or DNL of an ADC... (after its been designed on Cadence..?)
 

mahgoub

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designing a sar adc

you can also refert to some analog design books
 

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