Patent ID: 8207715

Claim:
A soft-start circuit to generate and output a soft-start voltage having a specified gradient, the soft-start circuit comprising: a slope voltage generator circuit to generate and output multiple slope voltages having different specified gradients, including a steepest slope voltage whose gradient is steepest among the gradients of the multiple slope voltages and a mildest slope voltage whose gradient is mildest among the gradients of the multiple slope voltages; a first voltage conversion circuit to receive the multiple slope voltages generated by the slope voltage generator circuit and output a first voltage whose gradient is milder than the gradient of the steepest slope voltage; a second voltage conversion circuit to receive the multiple slope voltages generated by the slope voltage generator circuit and output a second voltage whose gradient is milder than the gradient of the steepest slope voltage; and a selection circuit to receive a specified first reference voltage and a specified second reference voltage generated by a reference voltage generator circuit, the first voltage, and the second voltage, compare the second voltage with the specified second reference voltage, and output either the first voltage or the specified first reference voltage as the soft-start voltage in accordance with a comparison result generated by the selection circuit.