I am currently devising ways to shut off different circuit sections in an embedded circuit. Here is a breakdown of what I am doing and my initial idea. Currently I have a micro controller which is sampling multiple analog sensors and in between sampling it goes on to sleep mode, but know due to the low power constraints in the specs, I would like to shut off some of the individual analog circuit sections (equivalent to each sensor circuit), my current Idea is through the use of Op Amps and ICs with shutdown support, however I am also wondering whether I can actually use an "IC" to cutoff the power to a circuit section based on a digital output or via a digital interface (I2C, SPI... ETC) which will allow me to completely isolate that section from the circuit, but is this possible?
Any Feedback or if you can point me to application notes, design notes, research papers, links... I would greatly appreciate it.