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Ripple itself is a composite (non-sinusoidal) waveform consisting of harmonics of some fundamental frequency which is usually the original AC line frequency, but in the case of switched-mode power supplies, the fundamental frequency can be tens of kilohertz to megahertz. The characteristics and components of ripple depend on its source: there ...
The ripple reduction achieved by frequency pre-correction, although significant, is seen to be less successful than that achieved by the amplitude modulation methods of the previous section. However, it has been suggested [21] that by implementing cubic (rather than quadratic) phase pre-correction, comparable results can be achieved.
The common practice of defining the cutoff frequency at −3 dB is usually not applied to Chebyshev filters; instead the cutoff is taken as the point at which the gain falls to the value of the ripple for the final time. The 3 dB frequency is related to by:
The ripple like plot on the upper left is the pass band ripple and the ripple on the bottom right is the stop band ripple. The two dashed lines on the top left of the graph indicate the δ p and the two dashed lines on the bottom right indicate the δ s. All other frequencies listed indicate the extremal frequencies of the frequency response plot.
At the time, filters generated substantial ripple in the passband, and the choice of component values was highly interactive. Butterworth showed that a low-pass filter could be designed whose gain as a function of frequency (i.e., the magnitude of its frequency response) is:
The frequency response of a fourth-order elliptic low-pass filter with ε = 0.5 and ξ = 1.05.Also shown are the minimum gain in the passband and the maximum gain in the stopband, and the transition region between normalized frequency 1 and ξ A closeup of the transition region of the above plot.
In electrical circuits, ringing is an oscillation of a voltage or current.Ringing can be undesirable because it causes extra current to flow, thereby wasting energy and causing extra heating of the components; it can cause unwanted electromagnetic radiation to be emitted [citation needed]; it can increase settling time for the desired final state; and it may cause unwanted triggering of ...
For voltage regulators the PSRR is occasionally quoted (confusingly; to refer to output voltage change ratios), but often the concept is transferred to other terms relating changes in output voltage to input: Ripple rejection (RR) for low frequencies, line transient response for high frequencies, and line regulation for DC.