Controller for making a power converter start up normally and operational method thereof

A controller for making a power converter start up normally, comprising:

• a detection circuit for detecting a peak value of a resonant capacitor current flowing through a lower-bridge switch of the power converter during the power converter starting up;
• an upper-bridge power supply pre-charge circuit coupled to the detection circuit, wherein the upper-bridge power supply pre-charge circuit adjusts a lower-bridge turning-on time of a lower-bridge switch driving signal of the lower-bridge switch according to the peak value of the resonant capacitor current, and the upper-bridge power supply pre-charge circuit generates the lower-bridge switch driving signal according to the lower-bridge turning-on time and stops generating the lower-bridge switch driving signal when the peak value of the resonant capacitor current meets a second predetermined condition;
• and
• a driving signal generation circuit coupled to the upper-bridge power supply pre-charge circuit for generating the lower-bridge switch driving signal to the lower-bridge switch and an upper-bridge switch driving signal to an upper-bridge switch of the power converter to make the power converter operate normally after the upper-bridge power supply pre-charge circuit stops generating the lower-bridge switch driving signal.

An operational method of a controller which makes a power converter start up normally, wherein the controller comprises a detection circuit, an upper-bridge power supply pre-charge circuit and a driving signal generation circuit, the operational method comprising:

• the detection circuit detecting a feedback voltage during the power converter starting up, and adjusting a lower-bridge turning-on time of a lower-bridge switch driving signal of a lower-bridge switch of the power converter according to the feedback voltage;
• the upper-bridge power supply pre-charge circuit generating the lower-bridge switch driving signal according to the lower-bridge turning-on time;
• the upper-bridge power supply pre-charge circuit stopping generating the lower-bridge switch driving signal when the feedback voltage meets a first predetermined condition, wherein the first predetermined condition relates to a feedback peak voltage of the feedback voltage;
• and
• the driving signal generation circuit generating the lower-bridge switch driving signal to the lower-bridge switch and an upper-bridge switch driving signal to an upper-bridge switch of the power converter to make the power converter operate normally after upper-bridge power supply pre-charge circuit stops generating the lower-bridge switch driving signal.

An operational method of a controller which makes a power converter start up normally, wherein the controller comprises a detection circuit, an upper-bridge power supply pre-charge circuit and a driving signal generation circuit, the operational method comprising:

• the detection circuit detecting a peak value of a resonant capacitor current flowing through a lower-bridge switch of the power converter during the power converter starting up;
• the upper-bridge power supply pre-charge circuit adjusting a lower-bridge turning-on time of a lower-bridge switch driving signal of the lower-bridge switch according to the peak value of the resonant capacitor current, and generating the lower-bridge switch driving signal according to the lower-bridge turning-on time;
• the upper-bridge power supply pre-charge circuit stopping generating the lower-bridge switch driving signal when the peak value of the resonant capacitor current meets a second predetermined condition;
• and
• the driving signal generation circuit generating the lower-bridge switch driving signal to the lower-bridge switch and an upper-bridge switch driving signal to an upper-bridge switch of the power converter to make the power converter operate normally after the upper-bridge power supply pre-charge circuit stops generating the lower-bridge switch driving signal.