filtering input for ADC

[Mosaic]

Depending on your supply, you could connect the fast diode (low dropout) to supply directly (as shown on attachment). This is what most of our low-cost products use. We do use TVS for heftier protection (and when power supply can't take surge - such as lightning applications).

Yes...for automotive load dump SAE spec....you need the TVS and a 20K amp MOV to deal with it. The TVS clamps the small /fast transients and the MOV backs it up for the big Load dumps.