| 摘要 |
PROBLEM TO BE SOLVED: To suppress switching loss, voltage stress, and EMI of a semiconductor element.SOLUTION: When a MOSFET Qm is turned on, a current flows from a DC power supply 2 via a first resonance path passing through the MOSFET Qm, a capacitor C2, a diode D3, an inductor Ls, and a capacitor C1. If the capacitance value of the capacitor C1 is smaller than that of the capacitor C2, a voltage of the capacitor C1 reaches an input voltage Vs prior to a voltage of the capacitor C2, and the energy of the inductor Ls is moved to the capacitor C2 via a second resonance path passing through the inductor Ls, a diode D1, the capacitor C2, and the diode D3. When a resonance current becomes zero, the voltage of the capacitor C2 reaches near the input voltage Vs. When the MOSFET Qm is turned off, storage charges of the capacitors C1 and C2 flow via the diode D1, a diode D2, and an inductor Lm. Then, a reflux current flows via a diode Df. |
