| 摘要 |
PROBLEM TO BE SOLVED: To provide a power-supply circuit that allows performing more-secure current control and more-secure overcurrent protection and to provide a lighting device.SOLUTION: There is provided a power-supply circuit having a DC-DC converter and an overcurrent protection section. The DC-DC converter converts a first DC voltage into a second DC voltage and supplies the second DC voltage to a DC load. The overcurrent protection section feedback-controls the DC-DC converter on the basis of a current flowing through the DC load. The DC-DC converter has a normally-on-type switching element. The switching element includes a first electrode, a second electrode, and a third electrode for controlling a current flowing between the first electrode and the second electrode, and has a first state and a second state in which the current flowing between the first electrode and the second electrode is smaller than the current flowing in the first state. The overcurrent protection section places the switching element into the second state when the current flowing through the DC load is larger than a reference value. |
