Buck DC-DC converter with dual feedback control
First Claim
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 first gain circuit configured to generate a first feedback signal 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 first feedback signal;
a second gain circuit configured to generate a second feedback signal indicative of the regulated output voltage;
an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a first reference signal and to generate an output signal having a magnitude indicative the difference between the second feedback signal and the first reference signal; and
a comparator configured to receive the output signal of the OTA and the first feedback signal and to generate a comparator output signal having an output level indicative of the difference between the output signal of the OTA and the first feedback signal,wherein the first gain circuit comprises a voltage divider having a first divider ratio and the second gain circuit comprises a voltage divider having a second divider ratio, the first divider ratio being the same as or different from the second divider ratio.
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Accused Products
Abstract
A buck switching regulator includes a feedback control circuit including a first gain circuit configured to generate a first feedback signal 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 first feedback signal; a second gain circuit configured to generate a second feedback signal indicative of the regulated output voltage; an operational transconductance amplifier (OTA) configured to generate an output signal having a magnitude indicative the difference between the second feedback signal and the first reference signal; and a comparator configured to generate a comparator output signal having an output level indicative of the difference between the output signal of the OTA and the first feedback signal. As thus configured, the buck switching regulator generates an output voltage with increased accuracy and fast transient response.
37 Citations
14 Claims
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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:
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a first gain circuit configured to generate a first feedback signal 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 first feedback signal; a second gain circuit configured to generate a second feedback signal indicative of the regulated output voltage; an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a first reference signal and to generate an output signal having a magnitude indicative the difference between the second feedback signal and the first reference signal; and a comparator configured to receive the output signal of the OTA and the first feedback signal and to generate a comparator output signal having an output level indicative of the difference between the output signal of the OTA and the first feedback signal, wherein the first gain circuit comprises a voltage divider having a first divider ratio and the second gain circuit comprises a voltage divider having a second divider ratio, the first divider ratio being the same as or different from the second divider ratio. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method in buck switching regulator receiving an input voltage and controlling a high-side switch and a low-side switch using 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 circuit to generate a regulated output voltage having a substantially constant magnitude on an output node, the method comprising:
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generating a first feedback signal indicative of the regulated output voltage; generating a ripple signal using the switching output voltage; injecting the ripple signal to the first feedback signal; generating a second feedback signal indicative of the regulated output voltage; generating using an operational transconductance amplifier (OTA) an output signal having a magnitude indicative the difference between the second feedback signal and a first reference signal; and generating using a comparator a comparator output signal having an output level indicative of the difference between the output signal of the OTA and the first feedback signal, wherein generating a first feedback signal indicative of the regulated output voltage comprises dividing the regulated output voltage by a first divider ratio to generate the first feedback signal; and
generating a second feedback signal indicative of the regulated output voltage comprises dividing the regulated output voltage by a second divider ratio to generate the second feedback signal, the first divider ratio being the same as or different from the second divider ratio. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification