| 摘要 |
PURPOSE: A converter is provided to minimize a switching loss by detecting a lowest point of a valley through a valley detecting part and a start-up circuit. CONSTITUTION: A converter includes a first switch, an energy delivery device, and a switching control part(510). The energy delivery device converts input energy into output energy according to a switching operation of the first switch. The switching control part includes a valley detecting part(514), a PWM control part(518), and a second switch. When a voltage between a first terminal and a second terminal of the first switch is delivered to a lowest point of a resonant wavelength, the valley detecting part changes an output signal from a low level to a high level. The PWM control part turns on the first switch according to the output signal of the valley detecting part. A first terminal of the second switch is connected to the first terminal of the first switch. |
