Switching regulator and controller circuit and control method thereof

A controller circuit for use in a switching regulator, wherein the switching regulator includes a power stage circuit and the controller circuit, the power stage circuit including an inductor and at least one power switch, wherein the at least one power switch is coupled to the inductor, and is configured to operate according to a switch control signal, to control a conduction status of the inductor, so as to convert an input voltage to an output voltage;

• wherein the controller circuit is coupled to the power stage circuit, and is configured to operably generate the switch control signal according to a feedback signal and a reference signal, wherein the feedback signal related to the output voltage and the reference signal is related to a dynamic change of a target level of the output voltage, the controller circuit comprising:
• a first amplification circuit, which is configured to operably generate an amplification signal according to a difference between a low-pass filtered signal and the feedback signal, wherein the low-pass filtered signal is related to a signal generated by low-pass filtering the reference signal based on a first predetermined bandwidth;
• a second amplification circuit, which is configured to operably generate an adjustment signal according to a difference between the feedback signal and a fast response signal;
• a ramp signal generation circuit, which is configured to operably generate a ramp signal according to a clock signal;
• and
• a comparator, which is configured to operably compare the amplification signal and the ramp signal, to generate a pulse width modulation (PWM) signal, wherein the controller circuit generates the switch control signal according to the PWM signal;
• wherein the adjustment signal is configured to operably adaptively adjust the amplification signal or the ramp signal, to reduce a response time or to mitigate or avoid an overshoot or an undershoot of the output voltage;
• wherein a voltage level of the fast response signal is between a voltage level of the low-pass filtered signal and a voltage level of the reference signal.

A control method for controlling a switching regulator, comprising:

• operating a power switch according to a switch control signal, to control a conduction status of an inductor, so as to convert an input voltage to an output voltage;
• generating an amplification signal according to a difference between a low-pass filtered signal and a feedback signal, wherein the feedback signal is related to the output voltage and wherein the low-pass filtered signal is related to a signal generated by low-pass filtering the reference signal based on a first predetermined bandwidth, and wherein the reference signal is related to dynamic change of a target level of the output voltage;
• generating an adjustment signal according to a difference between the feedback signal and a fast response signal;
• generating a ramp signal according to a clock signal;
• and
• comparing the amplification signal and the ramp signal, to generate a pulse width modulation (PWM) signal, so as to generate the switch control signal according to the PWM signal;
• wherein the adjustment signal is configured to operably adaptively adjust the amplification signal or the ramp signal, to reduce a response time or to mitigate or avoid an overshoot or an undershoot of the output voltage;
• wherein a voltage level of the fast response signal is between a voltage level of the low-pass filtered signal and a voltage level of the reference signal.