Universally stable output filter

Abstract

In accordance with the teachings of this invention a novel method and apparatus is taught which provides for the stabilizing of an output signal through an output circuit having a compensation circuit coupled with an output capacitor, such that the compensation circuit is configured to compensate for an equivalent series resistance of the output capacitor. The compensation circuit compensates for the equivalent series resistance by providing a shift in a phase of the output signal to stabilize the output signal. The shift in phase is accomplished through the addition of a second zero at a second zero frequency to stabilize the output signal. The second zero is added such that the second zero frequency is closer to a first pole frequency than a first zero frequency, where the first pole frequency is proportional to the equivalent series resistance and the first zero is proportional to the output capacitor. The compensation circuit includes at least a compensation inductor and a compensation resistor, and the output capacitor is a ceramic capacitor.

Dependencies are inferred from the claim text.