| 摘要 |
PROBLEM TO BE SOLVED: To prevent degradation of the power-supply characteristics of a switching power supply without depending on an input voltage range or an output voltage variable range.SOLUTION: A switching power supply having an LLC resonant circuit and switch elements Q1 and Q2 detects error between a voltage value of an output voltage and a target value of the output voltage determined by power supply voltage of a reference voltage source Vref, and passes a current according to the detection result to a phototransistor PC2. Further, an input voltage detection unit 20 detects an input voltage or a voltage according to the input voltage, and a current source S passes a current according to the detection result. |
