Power converter circuit and control circuit thereof

Abstract

The power converter circuit includes a control circuit, a pulse generation circuit, and a power stage circuit. The power stage circuit generates an output signal at the output node based on the pulse signal output from the pulse generation circuit. The control circuit includes an error amplifier circuit, a comparator circuit, a delay circuit, and a detection circuit. The error amplifier circuit outputs a compensation signal based on a reference signal and a feedback signal related to the output signal. The comparator circuit outputs a task signal to the pulse generation circuit based on the compensation signal and a ramp signal. The detection circuit detects sudden changes in the output signal based on the output signal and a delayed signal generated by the delay circuit, generating a response signal. The control circuit uses the response signal to control the error amplifier circuit or the comparator circuit to change the pulse period of the pulse signal, thereby regulating sudden changes in the output signal.

Claims

1. A control circuit suitable for a power converter circuit, wherein the power converter circuit includes a pulse generation circuit and a power stage circuit, the pulse generation circuit being used to output a pulse signal, the power stage circuit being used to generate an output signal at an output node based on the pulse signal, and the control circuit including: an error amplifier circuit coupled to the output node, used to output a compensation signal based on the difference between a reference signal and a feedback signal associated with the output signal; a comparator circuit coupled to the error amplifier circuit, used to output a task signal to the pulse generation circuit based on the compensation signal and a ramp signal, and used to control the task signal to have a consistent energy level when the compensation signal exceeds the ramp signal; and an output change detection circuit, including: A delay circuit is provided for receiving the output signal and delaying the output signal to generate a delayed signal; and a detection circuit is coupled to at least one of the delay circuit, the error amplifier circuit, and the comparator circuit, and is used to detect a sudden change in the output signal based on the output signal and the delayed signal to generate a response signal, wherein the output change detection circuit is used to control the error amplifier circuit or the comparator circuit using the response signal to change a pulse period of the pulse signal, thereby adjusting the sudden change in the output signal.

2. The control circuit as claimed in claim 1, wherein the delay circuit includes a delay unit, and the detection circuit includes: a first comparator coupled to the delay unit for receiving the output signal and the delay signal, and for comparing the output signal and the delay signal to generate a first comparison signal, wherein the first comparison signal has the enable level when the voltage level of the delay signal is greater than the voltage level of the output signal; a first current generating circuit coupled to a power supply voltage for generating a charging current; and a first switching circuit coupled to the first current generating circuit and a first node for switching from an off state to an on state according to the first comparison signal with the enable level, wherein the charging current flows to the first node through the first switching circuit in the on state, and wherein the reaction signal is generated at the first node.

3. The control circuit as claimed in claim 2, wherein the detection circuit further comprises: a second comparator coupled to the delay circuit for receiving the output signal and the delay signal, and for comparing the output signal and the delay signal to generate a second comparison signal, wherein the second comparison signal has a uniform enable level when the voltage level of the output signal is greater than the voltage level of the delay signal; a second current generating circuit coupled to a ground terminal for generating a discharge current; and a second switching circuit coupled to the second current generating circuit and the first node for switching from the off state to the on state according to the second comparison signal of the enable level, wherein the discharge current flows from the first node to the ground terminal through the second switching circuit in the on state, wherein the response signal is the charging current or the discharging current.

4. The control circuit as claimed in claim 1, wherein the delay circuit includes a sample-and-hold circuit, and the detection circuit includes: a transconductance amplifier circuit coupled to the sample-and-hold circuit for receiving the output signal and the delay signal, and for generating a charging current or a discharging current as the response signal based on the output signal and the delay signal.

5. The control circuit as claimed in claim 1, wherein the response signal includes an adjustment current, wherein the control circuit further includes a current-to-voltage conversion circuit coupled to the detection circuit and used to convert the adjustment current into an adjustment voltage, wherein the adjustment voltage is used to adjust the reference signal, the feedback signal, or the ramp signal.

6. The control circuit as claimed in claim 5, further comprising: a subtraction circuit coupled to one of an inverting input terminal of the error amplifier circuit and an inverting input terminal of the comparator circuit and the current-to-voltage conversion circuit, for subtracting the adjustment voltage from one of the feedback signal and the ramp signal.

7. The control circuit as described in claim 5 further comprises: an adder circuit coupled to a non-inverting input of the error amplifier circuit and the current-to-voltage conversion circuit, and used to add the adjustment voltage to the reference signal.

8. The control circuit as claimed in claim 1, wherein the response signal includes an adjustment current, and wherein the control circuit further includes an adder circuit coupled to a non-inverting input of the comparator circuit and the detection circuit, for adding the adjustment current to an error current corresponding to the compensation signal.

9. A power converter circuit, comprising: a pulse generation circuit for outputting a pulse signal; a power stage circuit coupled to the pulse generation circuit and an output node of the power converter circuit, and for generating an output signal at the output node based on the pulse signal; and a control circuit coupled to the pulse generation circuit and the output node, and comprising: an error amplifier circuit coupled to the output node, and for outputting a compensation signal based on the difference between a reference signal and a feedback signal associated with the output signal; a comparator circuit coupled to the error amplifier circuit, for outputting a task signal to the pulse generation circuit based on the compensation signal and a ramp signal, and for controlling the task signal to have a consistent energy level when the compensation signal exceeds the ramp signal; and an output change detection circuit, comprising: A delay circuit is provided for receiving the output signal and delaying the output signal to generate a delayed signal; and a detection circuit is coupled to at least one of the delay circuit, the error amplifier circuit, and the comparator circuit, and is used to detect a sudden change in the output signal based on the output signal and the delayed signal to generate a response signal, wherein the output change detection circuit is used to control the error amplifier circuit or the comparator circuit using the response signal to change a pulse period of the pulse signal, thereby adjusting the sudden change in the output signal.

10. The power converter circuit of claim 9, wherein the output change detection circuit is coupled to at least one of the error amplifier circuit and the comparator circuit, and is used to adjust the reference signal, the feedback signal, the compensation signal or the ramp signal with the response signal to change the pulse period of the pulse signal when the sudden change of the output signal is detected.

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