Abstract: A voltage conversion apparatus, a control method, and a power supply device. The voltage conversion apparatus includes a control circuit. The control circuit is configured to: obtain a first sampling voltage and a second sampling voltage; detect a resonant period based on the second sampling voltage when it is determined, based on the first sampling voltage, that a voltage range of an output voltage of the voltage conversion apparatus changes and a voltage threshold is exceeded; and output a drive signal based on the detected resonant period. The drive signal is used to control turn-on and turn-off of a first switching transistor and a second switching transistor.

Abstract: A power supply apparatus includes a totem-pole power factor correction (PFC) circuit and a control apparatus, and the totem-pole PFC circuit includes a first switching transistor and a second switching transistor. The control apparatus includes a controller and a dead time detection circuit, and the dead time detection circuit includes a detection capacitor and a detection resistor. A first end of the detection capacitor is connected to a first reference point, a second end of the detection capacitor is connected to a first end of the detection resistor, and a second end of the detection resistor is grounded. The controller is configured to, respectively, control an on/off status of the first switching transistor and an on/off status of the second switching transistor based on a voltage of the detection resistor and polarity of a voltage input by an alternating current input source.

Abstract: A power conversion circuit and a power conversion circuit control method. The power conversion circuit determines polarity of an alternating current voltage by using a PFC circuit controller, determines, based on a current of an inductor, a signal for controlling a secondary switch to be turned off, determines, based on a voltage at a midpoint of a series connection between a switching transistor S1 and a switching transistor S2, a signal for controlling the secondary switch to be turned on again and a signal for controlling a primary switch to be turned off, and performs PWM control on the switching transistor S1 and the switching transistor S2.

Abstract: A noise suppression method and apparatus for a totem pole power factor correction (PFC) circuit and an electronic device are provided. In response to a determination that an alternating current of the totem pole PFC circuit is switched at a zero crossing, a control signal is sent to a switch that enables a PFC inductor in the totem pole PFC circuit to charge or discharge. After the switch is turned off for a first period of time, the switch is turned on again for a second period of time.