In an article entitled "Transformer-Coupled Front-End for Wideband A/D Converters", Rob Reeder mentions that many of ADI’s switched-capacitor ADC input impedance values can be downloaded in spreadsheet form at the ADC’s product page on the Analog Devices website. I am looking for data on the differential input impedance vs frequency for the AD9629-20, but couldn't find it on the web site. Have measurements been made for this device?
The single Zeus (AD9609/29/49) S-Parameters are the same as the dual Zeus (AD9204/31/51) family. It has the same ADC core just reduced to one channel.