| 摘要 |
PROBLEM TO BE SOLVED: To curb voltage fluctuation of a power source device.SOLUTION: In one embodiment, an output transistor of a power source device has one end provided with an input voltage, while the other end provides an output voltage. A voltage division unit divides the output voltage, generating the divided output voltage as a feedback voltage. An output voltage changeover transistor, which has one end connected to a feedback voltage side, is turned on/off in accordance with an output voltage changeover signal. A first capacitor has one end connected to the same end of the output voltage changeover transistor with the other end connected to a control terminal of the output voltage changeover transistor. A differential amplifier circuit has a first input unit and a second input unit provided with a reference voltage and the feedback voltage respectively. With the output voltage changeover transistor turned on, the second input unit is provided with a first feedback voltage, while the second input voltage is provided with a second feedback voltage from the voltage division unit which is higher than a first reference voltage with the output voltage changeover transistor turned off. |
