Patent ID: 9455626
Filing Date: 2016-09-27
CPC Classification: H02M

Claim Text:
1. A buck switching regulator being configured to receiving an input voltage and to generate a regulated output voltage, the buck switching regulator controlling a high-side switch and a low-side switch based on a feedback control scheme to drive a switch output node for generating a switching output voltage, the switch output node being coupled to an LC filter to generate the regulated output voltage having a substantially constant magnitude on an output node, the buck switching regulator including a feedback control circuit comprising: a feedback network including first and second gain circuits configured to generate first and second feedback signals, respectively, indicative of the regulated output voltage; a ripple generation circuit configured to generate a ripple signal using the switching output voltage and to inject the ripple signal to the second gain circuit; and a four-input comparator having first and second positive input terminals configured to receive a reference signal, a first negative input terminal configured to receive the second feedback signal with the injected ripple signal, and a second negative input terminal configured to receive the first feedback signal with the DC component only of the regulated output voltage, the four-input comparator being configured to generate a comparator output signal having an output level being a function of the first feedback signal, the second feedback signal and the reference signal, wherein the first feedback signal is applied to shift the comparison threshold for the comparison between the second feedback signal and the reference signal to reduce a voltage offset in the regulated output voltage due to the injected ripple signal at the second gain circuit.