SWITCH CONTROLLER, POWER SUPPLY DEVICE COMPRISING THE SAME, AND DRIVING METHOD OF THE POWER SUPPLY DEVICE

摘要

The embodiment of the present invention relates to a power supply device implemented by a high-side buck converter, a driving method, and a switch control device applied to the power supply device. The power supply device comprises a power switch including one end for receiving input power; a diode is positioned between the other end of the power switch and the ground; and a sensing resistor which is positioned between the other end of the power switch and an inductor. When a light emitting diode (LED) line is connected between the inductor and the ground, the switch control device compares a modulation sensing voltage, a high peak reference voltage, and a low peak reference voltage according to a sensing voltage generated in the sensing resistor. The switch control device controls a switching operation of the power switch according to a comparison result. The high peak reference voltage and the low peak reference voltage control the upper limit and the lower limit of LED currents which flow in the LED line.