| 摘要 |
A power source circuit includes a first transistor as an output switch, a second transistor as a load switch, a reference voltage generating section, a soft start voltage generating section, a feedback voltage generating section, first and second error amplifiers, and first and second offset control sections. The first error amplifier controls a conduction state of the first transistor based on a difference between a soft start voltage obtained by adding an offset voltage to a soft start voltage or a reference voltage, whichever is smaller, and a feedback voltage. The second error amplifier controls a conduction state of the second transistor based on a difference between a soft start voltage obtained by adding an offset voltage to the soft start voltage and the feedback voltage. |
| 主权项 |
1. A power source circuit comprising:
a first switch connected to an input power source; a second switch connected between the first switch and an output node; a reference voltage generating section configured to generate a reference voltage; a soft start voltage generating section configured to generate a first soft start voltage in response to a start signal; a feedback voltage generating section configured to generate a feedback voltage from an output voltage at the output node; a first error amplifier configured to receive the reference voltage, a second soft start voltage obtained by adding a first offset voltage to the first soft start voltage and the feedback voltage, and amplify a difference between the second soft start voltage or the reference voltage, whichever is smaller, and the feedback voltage to generate a control signal for the first switch; and a second error amplifier configured to receive a third soft start voltage obtained by adding a second offset voltage to the first soft start voltage and the feedback voltage, and amplify a difference between the third soft start voltage and the feedback voltage to generate a control signal for the second switch. |
