an energy storage element;

a power driver, driving the energy storage element to provide the output voltage by coupling the input voltage to the energy storage element according to a control signal;

a feedback circuit, generating a feedback voltage based on the output voltage;

an error amplifier, receiving the feedback voltage as well as a reference voltage for generation of an amplified error;

a control signal generator, generating the control signal based on the amplified error generated by the error amplifier, to provide the control signal to operate the power driver; and

a first comparator, enabled in a soft-start stage till the output voltage reaches a stable status, to compare the amplified error with a critical value;

wherein:

the input voltage is disconnected from the energy storage element when the first comparator enabled in the soft-start stage shows that the amplified error is greater than the critical value;

the control signal generator comprises a pulse width modulation signal generator and a second comparator, wherein the pulse width modulation signal generator generates a pulse width modulation signal to be transformed into the control signal for operating the power driver, and the second comparator compares the amplified error with a feedback current of the power converter to output a comparison result to the pulse width modulation signal generator to adjust a duty cycle of the pulse width modulation signal;

the power converter further comprises a current detector and a slope compensator, wherein the current detector detects a current generated while the input voltage is coupled to the energy storage element, and, the slope compensator compensates for a variation slope of the current detected by the current detector, to generate the feedback current to be coupled to the current detector;

the critical value depends on a direct-current voltage, a slope voltage, a current detection voltage, and a fault tolerance;

the direct-current voltage is a direct-current offset for an output range of the error amplifier;

the slope voltage depends on electrical characteristics of the slope compensator; and

the current detection voltage depends on electrical characteristics of the current detector.