| 主权项 |
1. A control circuit of a power converter, the power converter comprising an inductor and a first power switch, a first terminal of the first power switch being coupled with a predetermined terminal of the inductor, and a second terminal of the first power switch being coupled with a fixed voltage terminal, the control circuit comprising:
a zero current detection circuit, configured to operably detect a current flowing between the predetermined terminal and a voltage output terminal of the power converter to generate a zero current detection signal; an adjusting circuit, coupled with the zero current detection circuit, configured to operably generate an adjustment signal according to the zero current detection signal; a clock signal generating circuit, coupled with the adjusting circuit, configured to operably adjust a frequency of a clock signal according to the adjustment signal; a periodical signal generating circuit, coupled with the clock signal generating circuit, configured to operably generate a periodical signal according to the clock signal; an error detection circuit, configured to operably generate an error signal according to a reference signal and a feedback signal corresponding to an output voltage signal of the power converter when coupled with the power converter; and a control signal generating circuit, coupled with the periodical signal generating circuit and the error detection circuit, configured to operably generate a control signal according to the periodical signal and the error signal to control operations of the first power switch; wherein when the power converter operates at a discontinuous conduction mode, if a width of a pulse generated by the zero current detection circuit in multiple clock cycles is less than a first predetermined width and an amount of pulses generated by the zero current detection circuit in the multiple clock cycles is greater than a first predetermined value, the adjusting circuit utilizes the adjustment signal to control the clock signal generating circuit to increase the frequency of the clock signal, so as to enable the periodical signal generating circuit to increase a frequency of the periodical signal to switch the power converter from the discontinuous conduction mode to a continuous conduction mode, and a first switching frequency of the first power switch at the discontinuous conduction mode is lower than a second switching frequency of the first power switch at the continuous conduction mode. |
