...Can you recommend app note or other resource on charge injection?
Besides
Art of Electronics, other relevant books you might find helpful are
Circuit Designer's Companion, and
Designing with Analog Switches (Older but still applies). Take a look at how MUX508 / 509 parts work from TI (and AD508G from ADI, etc.). Then take a look at the DMOS switches from Linear Systems. LS makes a lot of of the excellent parts from Intersil, Siliconix, etc. (when those companies got dissolved or bought out, LS took over the fet and some of the BJT parts) , and then LS made new and improved parts along the way. A lot of designers don't even realize the value of these parts anymore, but they can be extremely useful in precision analog designs:
http://linearsystems.com/lsdata/others/DMOSAnalogSwitchIntroduction.pdfIf you aren't aware, the founder of Linear Integrated Systems was John Hall - who was also a co-founder of Intersil. He knew what he was doing when it came to building performance FETs.
Notice that if you're looking at datasheets or app notes from Vishay or ON Semi, they are probably warmed over versions from the 70's thru 90's from Siliconix, Fairchild and sometimes Motorola sheets will pop up. Etc. These were the big players.
After that, look at older test equipment designs, and then by all means get your hands dirty testing your own circuits and make some discoveries - best way to learn.
Here's some inspiration on how to measure charge injection for yourself - see figure 4:
http://www.vishay.com/docs/70606/70606.pdfHINT: You can't get rid of charge injection completely, but you can do a good job canceling (at least some of) the effects out if you're careful.