I know that one can calculate the self-resonant frequency for an LC filter of a simple buck converter(having one inductor and one capacitor at the output) by the formula 0.5*pi*sqrt(LC). My question is if we add another inductor at the output of the converter following the capacitor, forming T type LC filter, will the self resonant frequency for this circuit remain the same ? Or will it change ? What i mean to ask is that the self resonant frequency of circuit (a) and circuit (b) would be the same ?
The reason for asking this question is that i am supposed to design a current controller for my buck converter. And the controller should be designed in such a way that the controller bandwidth is higher than the circuit's self-oscillation frequency. So initially i had no T type filter, just a simple circuit like (a), and i designed a current controller whose bandwidth is greater than 0.5*pi*sqrt(LC), but later i added another inductor to filter out the current more (which is being supplied to the load). So now i am not sure if my circuit filters self resonating frequency would be same or not (which means my old controller design would work fine or not)
P.S my question may be very basic or stupid, but i dont have detail idea of power electronic components, so i posted the question as i couldnt find anything regarding this on the internet.
Your helpful suggestions and comments would be appreciated.