| 摘要 |
A power supply apparatus A according to the present invention comprises a drive control circuit for generating an on/off control signal of an output transistor; an overcurrent protection circuit for directly or indirectly monitoring a coil current and generating an overcurrent detection signal; and a soft-start control circuit for suppressing a rise in an output voltage by using a soft-start voltage for starting an increase slowly after startup of the power supply apparatus, wherein, when the coil current is in an overcurrent state, the drive control circuit repeats a forced reset operation of the on/off control signal in accordance with the overcurrent detection signal, and a set operation of the on/off control signal in accordance with a clock signal of a predetermined frequency, as a pulse-by-pulse overcurrent protection operation; and the soft-start control circuit gradually reduces the soft-start voltage as a reset operation in accordance with the overcurrent detection signal. |
