what architecture is used to implement the gain stage on the AD719x.
Are you asking this question because you want to design an external analog front end for AD719x? May I know what is your application and why do you need this type of information? The classic 3-op amp is the most popular configuration for Instrumentation amplifier. I am not sure about the specific design architecture of the AD719x digitally gain programmable instrumentation amplifier, however, we have a recommended ADC driver for AD719x, AD8639 (for higher supply voltages up to +-8V), ADA4051-2(for low noise and low power applications) and AD8539 (for more precision and great temperature dirft specs). These are all auto-zero op amp.