Voltage converter circuit and associated control method to improve transient performance
AssigneeChengdu Monolithic Power Systems Co., Ltd.
InventorsBo Yang, Xiaoyu Xi
Life of this patent
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Abstract
A converter circuit has an error amplifier to provide an error signal; a proportional amplifier to provide a gain signal according the error signal and an output voltage of the converter circuit; a first comparator, generating a pulse signal according to the gain signal and a comparison signal; and a timer, generating a timing signal according to the pulse signal to indicate the on time and the off time of the converter circuit; and wherein either the gain signal or the comparison signal comprises a ramp component, and wherein the on time of the converter circuit is constant.
Claims22
A switch-mode converter circuit for converting an input voltage to an output voltage, the converter circuit comprising:
- a primary switch;
- an error amplifier, having two inputs and an output, wherein the two inputs respectively receive a feedback signal of the output voltage and a reference signal, and wherein the output generates an error signal;
- a proportional amplifier, having two inputs and an output, wherein the two inputs respectively receive the output voltage and the error signal, and wherein the output generates a gain signal, wherein the gain signal proportionally declines in response to an increase of the output voltage;
- a first comparator, having two inputs and an output, wherein the two inputs respectively receive the gain signal and a comparison signal, and wherein the output generates a pulse signal;
- and
- a timer, having an input and an output, wherein the input is coupled to the output of the first comparator, and wherein the output generates a timing signal to indicate an on time and an off time of the primary switch;
- wherein either the gain signal or the comparison signal comprises a ramp component, wherein the ramp component at least depends on the output voltage, and wherein the on time is constant.
A method for converting an input voltage to an output voltage via a converter circuit, comprising:
- generating an error signal according to a feedback signal and a reference signal;
- sending the error signal and the output voltage to a first proportional amplifier, configured to obtain a gain signal, wherein the gain signal proportionally declines in response to an increase of the output voltage;
- comparing the gain signal with a comparison signal, configured to generate a pulse signal;
- generating a timing signal to indicate an on time and an off time of a converter circuit according to the pulse signal;
- and
- controlling at least a primary switch in the converter circuit on and off according to the timing signal;
- wherein either of the gain signal or the comparison signal comprises a ramp component, wherein the ramp component at least depends on the output voltage, and wherein the on time of the converter is constant.
Dependencies are inferred from the claim text.