Abstract: A Totem Pole PFC circuit includes at least one fast-switching leg, a slow-switching leg, and a control unit. Each fast-switching leg includes a fast-switching upper switch and a fast-switching lower switch. The slow-switching leg is coupled in parallel to the at least one fast-switching leg, and the slow-switching leg includes a slow-switching upper switch and a slow-switching lower switch. The control unit receives an AC voltage with a phase angle, and the control unit includes a current detection loop, a voltage detection loop, and a control loop. The control loop generates a second control signal assembly to respectively control the slow-switching upper switch and the slow-switching lower switch. The control loop controls the second control signal assembly to follow the phase angle, and dynamically adjusts a duty cycle of the second control signal assembly to turn on or turn off the slow-switching upper switch and the slow-switching lower switch.

Abstract: A Totem Pole PFC circuit includes at least one fast-switching leg, a slow-switching leg, and a control unit. Each fast-switching leg includes a fast-switching upper switch and a fast-switching lower switch. The slow-switching leg is coupled in parallel to the at least one fast-switching leg, and the slow-switching leg includes a slow-switching upper switch and a slow-switching lower switch. The control unit receives an AC voltage with a phase angle, and the control unit includes a current detection loop, a voltage detection loop, and a control loop. The control loop generates a second control signal assembly to respectively control the slow-switching upper switch and the slow-switching lower switch. The control loop controls the second control signal assembly to follow the phase angle, and dynamically adjusts a duty cycle of the second control signal assembly to turn on or turn off the slow-switching upper switch and the slow-switching lower switch.

Abstract: A method for sizing a DNA molecule is disclosed, which comprises the following steps of: providing a DNA sizing device, comprising: a cover substrate; a substrate disposed on the cover substrate and comprising a first hole and a second hole; and a first slit-like channel disposed between the cover substrate and the substrate, wherein two ends of the first slit-like channel respectively connects to the first hole and the second hole; loading a sample comprising a DNA molecule to the first slit-like channel through the first hole, wherein the DNA molecule moves in a direction from the first hole to the second hole; detecting and recording an intensity and an area of a distribution of the DNA molecule; and analyzing the intensity and the area to obtain the size of a DNA molecule.

Abstract: A method for sizing a DNA molecule is disclosed, which comprises the following steps of: providing a DNA sizing device, comprising: a cover substrate; a substrate disposed on the cover substrate and comprising a first hole and a second hole; and a first slit-like channel disposed between the cover substrate and the substrate, wherein two ends of the first slit-like channel respectively connects to the first hole and the second hole; loading a sample comprising a DNA molecule to the first slit-like channel through the first hole, wherein the DNA molecule moves in a direction from the first hole to the second hole; detecting and recording an intensity and an area of a distribution of the DNA molecule; and analyzing the intensity and the area to obtain the size of a DNA molecule.