Voltage regulator including constant loop gain control
AssigneeIntersil Americas Inc.
InventorsWeihong Qiu, Shangyang Xiao, Nattorn Pongratanankul
Life of this patent
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Abstract
A voltage regulation circuit includes a power stage for generating a regulated output voltage responsive to an input voltage and at least one PWM signal. A voltage divider circuit is connected to the output of the power stage and generates a feedback voltage. First circuitry generates the at least one PWM signal responsive to a voltage error signal, a filtered output voltage signal and a ramp voltage signal. The filtered output voltage is used for substantially removing loop gain change caused by the voltage divider circuit. A voltage compensation circuit generates the voltage error signal responsive to a feedback voltage and a reference voltage.
Claims22
A voltage regulation circuit having a first feedback loop with a loop gain, the voltage regulation circuit comprising:
- a power stage configured to generate a regulated output voltage responsive to an input voltage and at least one PWM signal;
- a voltage divider circuit connected to the output of the power stage and configured to generate a feedback voltage from the regulated output voltage;
- a second feedback loop including a filter connected to the regulated output voltage and configured to provide a filtered output voltage signal;
- first circuitry configured to generate the at least one PWM signal responsive to a voltage error signal, the filtered output voltage signal from the second feedback loop, and a ramp voltage signal, wherein the first circuitry is configured to use the filtered output voltage signal for substantially removing a loop-gain variation of the first feedback loop due to the voltage divider circuit;
- and
- a voltage compensation circuit configured to generate the voltage error signal responsive to the feedback voltage and a reference voltage.
An integrated circuit for controlling a voltage regulator having a first feedback loop with a loop gain, the integrated circuit comprising:
- a pair of switching transistors configured to generate a phase voltage responsive to an input voltage and drive control signals;
- driver circuitry configured to generate the drive control signals responsive to a PWM signal;
- a second feedback loop including filter connected to the regulated output voltage and configured to provide a filtered output voltage signal;
- first circuitry configured to generate the PWM signal responsive to a voltage error signal, the filtered output voltage signal from the second feedback loop, and a ramp voltage signal, wherein the first circuitry is configured to use the filtered output voltage signal for substantially removing a loop-gain variation of the first feedback loop due to a voltage divider circuit connected to an output of the voltage regulator;
- and
- a voltage compensation circuit configured to generate the voltage error signal responsive to a feedback voltage and a reference voltage.
A method of voltage regulation comprising the steps of:
- generating a regulated output voltage by utilizing a first feedback loop having a loop gain, responsive to an input voltage and at least one PWM signal;
- monitoring a feedback voltage through a voltage divider;
- monitoring the regulated output voltage;
- filtering the regulated output voltage by utilizing a second feedback loop;
- generating a voltage error signal responsive to the feedback voltage and the reference voltage;
- removing a component of the loop gain of the first feedback loop caused by the voltage divider from the voltage error signal responsive to the filtered regulated output voltage;
- and
- generating the at least one PWM signal responsive to the voltage error signal having the component of the loop gain removed therefrom.
Dependencies are inferred from the claim text.