Using Equation 11, the minimum inductor value is 17.9 μH. A value of 18 μH is chosen for this design.

When using ceramic output filer capacitors, the recommended LC resonant frequency should be no more than 7 kHz. Since the output inductor is already selected at 18 μH, this limits the minimum output capacitor value to:

Equation 13.

The minimum capacitor value is calculated to be 29 μF. For this circuit a larger value of capacitor yields better transient response. Two 47 μF output capacitors are used for C3 and C4. It is important to note that the actual capacitance of ceramic capacitors decreases with applied voltage. In this example, the output voltage is set to 3.3 V, minimizing this effect.