Does the control signal from the digital section output to the analog section need to be isolated? The analog section requires a voltage ripple level of uV.
Depends on the signal and application. How often does this control signal change? Which analog signal should not ripple? How far away is it placed on your board from your analog signal, which is not allowed to have much ripple? Are there ground planes placed in between? How is your layer setup for the board? These are all questions which come into play here.
Thanks for your reply, I decided to add an optoelectronic isolator.