Abstract: The present disclosure relates to a totem pole bridgeless power factor correction device and a power supply system. The device includes a power factor correction module. The power factor correction module includes a first transistor, a second transistor, a third transistor, a fourth transistor, an inductor and a control module for generating a zeroth control signal in the first time period to control the third transistor and the fourth transistor to be in an off state, performing a zero-crossing detection on an AC voltage in the first time period, generating a first control signal to control a conduction state of the first transistor and the second transistor before the AC voltage crosses zero, and generating a second control signal to control the conduction state of the first transistor and the second transistor after the AC voltage crosses zero.

Abstract: An apparatus includes a capacitor coupled to a gate of a power switch, and a negative voltage adjustment device connected to a common node of the capacitor and the gate of the power switch, wherein the negative voltage adjustment device is configured such that after a turn-off signal is applied to the gate of the power switch, a voltage across the capacitor is maintained at a predetermined voltage level through a negative current provided by the negative voltage adjustment device.

Abstract: An apparatus includes a capacitor coupled to a power switch, wherein the capacitor is configured to provide a negative gate voltage to the power switch when a turn-off signal is applied to a gate of the power switch, and a sink and source power supply coupled to the capacitor, wherein the sink and source power supply has a first current limit for controlling a sink current flowing from the capacitor to the sink and source power supply, and a second current limit for controlling a source current flowing from the sink and source power supply to the capacitor.

Abstract: The invention relates to the field of power semiconductor devices. This invention discloses a drive circuit and device of a power switch. The input terminal of the drive circuit receives a pulse signal; the output terminal of the drive circuit is connected to a capacitor circuit. The capacitor circuit is used to provide a negative voltage for a first electrode of the power switch to turn off the power switch when the pulse signal is a turn-off signal; the drive circuit includes a capacitance adjustment unit. The capacitance adjustment unit includes a negative voltage adjustment element that can charge a capacitor whose voltage is lower than a predetermined voltage when the pulse signal is the turn-off signal.