This applet examines the influence that the values of the passive filter components have on the output voltage ripple and the physical dimensions of the passive components. If, for example, the switching frequency is kept constant and the value of the inductor and/or capacitor is made larger then the resonant frequency of the LC filter is reduced. This means that the magnitude of the switching frequency component appearing in the output voltage is reduced. However the physical sizes of the filter components become larger. If on the other hand the switching frequency is increased then the L & C values can be decreased to achieve the same output voltage switching ripple limit and therefore the size is also reduced.

• Change the value of the inductor and/or capacitor and observe the change in physical size and filtering performance.
• Adjust the switching frequency and observe the change in the magnitude of the output voltage switching ripple.