| 摘要 |
There is described a control device (100) of a switching circuit (200) for a resonant converter (1) having a direct current at the output (Iout); the switching circuit (200) comprises at least one half bridge of at least first (Q1) and second (Q2) transistors connected between an input voltage (Vin) and a reference voltage (GND). The half bridge is adapted to generate a periodic square wave voltage to drive the resonant circuit (300) of said resonant converter; the periodic square wave voltage ranges from a high voltage corresponding to the input voltage, to a low voltage corresponding to the reference voltage. The control device (100) is adapted to control said half bridge according to the time period of charging or discharging a capacitor (Ct) and comprises circuit means (101) adapted to synchronize the starting time instant (Tstart) of the time period of discharging or charging the capacitor (Ct) crossing the zero value of a signal (Vs) indicating the current (Is) flowing in the resonant circuit (300) and further means (102, 103) adapted to control the switching off of the first (Q1) or second (Q2) transistor at the end of the time period of discharging or charging the capacitor (Ct). |
