| 摘要 |
PROBLEM TO BE SOLVED: To improve the conversion efficiency of a power supply, and to perform current mode control under a light load in a case where a secondary side is synchronously rectified.SOLUTION: Provided is a power supply device with a DC/DC converter. The DC/DC converter comprises: a bridge circuit with a switching element; a transformer that has a primary side coil connected with the bridge circuit, and a secondary side coil insulated from the primary side coil; a synchronous rectification circuit connected with the secondary side coil; and a controller that on/off-controls the switching element included in the bridge circuit, by a current mode control system. The controller switches to a primary side current at a timing when a voltage at the primary side coil changes from negative to positive, switches to an inverted current obtained by inverting the primary side current at a timing when the voltage at the primary side coil changes from positive to negative, generates a control waveform on the basis of the primary side current and the inverted current, and on/off-controls the switching element by the current mode control system on the basis of the control waveform.SELECTED DRAWING: Figure 2 |
