Except for leakage spec, there are no indications in the datasheet (Rev.C) of the input impedance of the Main and Auxilliary A/D (with and without bufferring and/or PGA). It is almost impossible to design anything without these specs... dependence on the source impedance, anti-aliasing filters, etc...
Please provide these specifications.
This thread is somewhat related to the previous two postings:
Please answer the above two postings -- they are getting stale being unaswered for 5 days :-)