The first step in the design procedure is the selection of the output filter components. To simplify this process, Table 9-2 outlines possible inductor and capacitor value combinations.
Table 9-2 Recommended LC Output Filter Combinations
Inductor Value [µH](2) |
Output Capacitor Value [µF](1) |
4.7µF |
10µF |
22µF |
47µF |
100µF |
2.2 |
√ |
√(3) |
√ |
√ |
|
(1) Capacitance tolerance and bias voltage de-rating is anticipated. The effective capacitance varies by +20% and –50%.
(2) Inductor tolerance and current de-rating is anticipated. The effective inductance can vary by 20% and -30%.
(3) Typical application configuration. Other check marks indicate alternative filter combinations.