| 主权项 |
1. A power supply device comprising:
a control circuit including:
a reference signal generator which sets a target current and a target voltage according to an inputted dimming signal;a first comparator connected to the reference signal generator, comparing an output current supplied to a light-emitting element with the target current, outputting a signal in a current control mode, the control circuit controlling the output current to the target current in the current control mode; anda second comparator connected to the reference signal generator, comparing an output voltage supplied to the light-emitting element with the target voltage, outputting a signal in a voltage control mode, the control circuit controlling the output voltage to the target voltage in the voltage control mode, the control circuit switching between the current control mode and the voltage control mode by switching an output of the first comparator and an output of the second comparator according to a first voltage, the first voltage being the target voltage at which switching between the current control mode and the voltage control mode is carried out, and thus the control circuit dimming the light-emitting element according to the inputted dimming signal; and
a microcomputer connected to the control circuit, detecting a characteristic of the output current to the output voltage, setting the first voltage, outputting the first voltage to the control circuit. |
