Patent ID: 9608515
Date: 2017-03-28
CPC Classifications: H02M,H03H

Claim:
1. A circuit comprising: a switching regulator circuitry to generate a power supply signal based on a first tuning signal corresponding to a clock signal, the power supply signal including a signal component at a first frequency based on the first tuning signal; a notch filter circuit to filter the power supply signal, the notch filter circuit having an input-output frequency response that includes a stopband region having a center frequency and an attenuation level, the attenuation level of the stopband region being based at least in part on a second tuning signal; and a tuning circuit operable in at least two modes to generate the first and second tuning signals, the at least two modes including a tuning mode and a filtering mode, the tuning circuit being operable in the at least two modes to generate the second tuning signal such that the attenuation level of the stopband region is greater in the filtering mode than in the tuning mode, the tuning circuit being operable in the tuning mode to generate the first tuning signal such that the tuning circuit adjusts the first tuning signal based at least on the unfiltered power supply signal and the filtered power supply signal to match the center frequency of the stopband region with the frequency of the signal component of the power supply signal.