Power supply device having boosting circuit and boosting control applicable to electronic devices

A power supply device comprising:

• a first load circuit, including a backlight circuit for a display device having a plurality of light emitting diodes (LEDs), that operates by a first voltage;
• a second load circuit that operates by a second voltage higher than the first voltage;
• a boosting circuit that generates the first voltage if the power supply device is in a first driving mode, and generates the second voltage if the power supply device is in a second driving mode;
• a first feedback circuit that connects the first load circuit and the boosting circuit if the power supply device is in the first driving mode;
• a second feedback circuit that connects the first load circuit and the boosting circuit if the power supply device is in the second driving mode;
• and
• a control unit, including a microprocessor, that causes the first load circuit to operate if the power supply device is in the first driving mode, and causes the first load circuit and the second load circuit to operate if the power supply device is in the second driving node,
• wherein in the first driving mode,
• a detection resistor circuit is selected as a driving circuit for the first load circuit and the first feedback circuit is selected, and
• the boosting circuit performs a boosting operation based on an output of the first load circuit, thereby outputting output voltage Vout according to a sum of forward voltages Vf of the plurality of LEDs, resulting in the first load circuit being driven at a constant current;
• and
• wherein in the second driving mode,
• a constant-current circuit is selected as a driving circuit for the first load circuit and an output voltage detection circuit and the second feedback circuit is selected
• output voltage Vout of the boosting circuit is determined, and
• based on a voltage detected by the output voltage detection circuit, the boosting circuit generates output voltage Vout required to drive the second load circuit.