I am designing a buck converter circuit. The input is 9V and output is 15V, switching frequency is 25kHz.I have some equation based for the design.But what is the value i should assign for current ripple and voltage ripple.In the equations I have, i can find the value of inductor or capacitor but the values of ripple current and voltage is unknown.And I would also like to knw that, while designing should we consider the voltage drop across the diode
A buck converter reduces voltage. Yours is a boost converter that increases the voltage. All the details are on the datasheet for the buck/boost converter IC.