Method for controlling switched capacitor buck circuit of power supply and power supply

A power supply, comprising a buck circuit and a controller for controlling the buck circuit, wherein the buck circuit comprises a first switch, a first complementary switch, a second switch, a second complementary switch, a first capacitor, a first output inductor, and a second output inductor, wherein a first end of the second switch is connected to a voltage input terminal of the power supply, a second end of the second switch is connected to a first end of the first capacitor and a first end of the first switch, a second end of the first switch is connected to a first end of the first complementary switch and a first end of the first output inductor, a second end of the first capacitor is connected to a first end of the second complementary switch and a first end of the second output inductor, a second end of the first complementary switch and a second end of the second output inductor are connected to a voltage output terminal of the power supply, and

• wherein the controller is configured to:
• use a first duty cycle to control switching of the first switch;
• and
• use a second duty cycle to control switching of the second switch, a switching cycle of the first switch being equal to a switching cycle of the second switch with respect to cycle length,
• wherein the first duty cycle is greater than 0.5, and the second duty cycle is equal to 0.5,
• wherein the controller comprises:
• a first control unit with a first end coupled to a control terminal of the first switch and a second end coupled to a control terminal of the first complementary switch, the first control unit configured to send a control signal to the control terminal of the first switch and the control terminal of the first complementary switch;
• a second control unit with a first end coupled to a control terminal of the second switch and a second end coupled to a control terminal of the second complementary switch, the second control unit configured to send a control signal to the control terminal of the second switch and the control terminal of the second complementary switch;
• a duty cycle generation unit configured to generate the first duty cycle;
• and
• a duty cycle limiter coupled between the duty cycle generation unit and the second control unit, and configured to output the second duty cycle of 0.5 to the second control unit in response to determining that the first duty cycle received from the duty cycle generation unit is greater than 0.5.