| 摘要 |
A method for determining the bypass capacitors in order to achieve a target impedance over a wide frequency range. In one embodiment, a power distribution system of an electronic circuit includes at least one pair of planar conductors, including a power plane and a ground plane. A first capacitor bank may be defined to provide bypassing in a frequency range extending from a maximum frequency down to a first frequency (also referred to as a deviation frequency). The electrical characteristics, or parameters of the first capacitor bank may include a first capacitance, a first resistance, and a first inductance (C10, R10, and L10, respectively). The first resistance may be set to be less than or equal to the required target impedance for the frequency range covered by the first capacitor bank. After the characteristics have been defined for the first capacitor bank, a determination may be made for a required effective inductance of a potential second capacitor bank, which may be used to provide bypassing for a second frequency range. If the required effective inductance is greater than the inductance provided by the output and connection inductance of the power source, then no additional capacitor banks are required. However, if the inductance from the power source is greater than the required effective inductance, then a second capacitor bank may be required. The method may be repeated for additional capacitor banks. Eventually, the power source may be treated as a final capacitor bank with infinite capacitance.
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