Is there any document on adc design as detailed  and straightforward as the op amp design in Allen's CMOS book?
Thanks

Art,

as there are many different ADC topologies, each appearing with different flavors, you cannot expect having a straight-forward design document. The architecture choice depends mostly on your specifications in terms of speed (bandwidth) and resolution.

Unless you are going to do extensive investigation of sigma-delta converters, I would not recommend Schreier's book. It is a good book, but it is very exhaustive and as it has several contributors, it is difficult to read only part of it and still get the full picture.

As a starting point in ADC architectures and evaluation, I would recommend the following book:

Integrated Converters: D to A and A to D Architectures, Analysis and Simulation
Paul Jespers
Oxford University Press UK
ISBN: 0198564465

It covers all major ADC topologies and it has nice Matlab code included for evaluation of topologies and their trade-offs. I would grade it 4/5 (not 5/5 because it does not go into all the details, but that's also one of its strength) and suggest it to be added to the books section.

Concerning free tutorials on ADC specifications (probably not design though), you can also have a look at the appnotes of some major design houses (e.g. Maxim, ADI, ...).

Paul