Nice overview. LDO's 'can' get very expensive, especially if need >+/-8V. Also they're not really that simple, be very careful of the output requirements, especially output capacitor requirements for stability. Most require very specific type/ESR & values.
Technically yes, if you place enough filter stages you will create a higher order filter with sharp rolloff. However, for passive low-pass filters, you can end up adding new poles into the cascaded filter's transfer function as you add in these filter stages. The result is that you will have some resonances if you do not also add damping with a small amount of resistance.
13:50 , you mentioned that regulator noise transferred t oanother analog circuit, how we can handle this noise using buffer opamp circuit or your any recommendation?
