Re: LDO behavior
*For transient : You can imagine the pass-element for very fast changes seen as a current source [Ref Dr Millikan paper for cap free ldo](as before EA catch-up the EA output voltage is constant ) & so varying the load can be seen by two points of views :
1) Varied resistance :for ex. load resistance varied from high resistance to low resistance,& so the current source sees a low resistance while passing the same current & so the voltage drops down.And vice versa.
2)Varied Current source:For ex. the driven current varied from light load(low current) to heavy load(high current) ,in this case you can get calculate the output voltage as the current passes through the voltage divider times its total series resistance so here as the pass-element current is constant the increase in load current accompanied by decrease in volt. divider current which means output voltage drop.And vice versa.
[Out cap value smoothing this process by delivering some instantaneous charges that overcome fast voltage changes.]