Abstract: The power supply device includes a power switch including one terminal to which an input voltage is transferred; an inductor including one terminal connected to another terminal of the power switch; a diode connected between a ground and a floating ground; a sensing resistor connected between the floating ground and the one terminal of the inductor. A switch controller compares a modulation sensing voltage depending on a sensing voltage generated from the sensing resistor with a high peak reference and a low peak reference when a LED string is connected between an inductor and the ground. The switch controller controls a switching operation of a power switch according to the comparison result. The high peak reference and the low peak reference are references for controlling an upper limit and a lower limit of an LED current flowing through the LED string, respectively.

Abstract: The power supply device includes a power switch including one terminal to which an input voltage is transferred; an inductor including one terminal connected to another terminal of the power switch; a diode connected between a ground and a floating ground; a sensing resistor connected between the floating ground and the one terminal of the inductor. A switch controller compares a modulation sensing voltage depending on a sensing voltage generated from the sensing resistor with a high peak reference and a low peak reference when a LED string is connected between an inductor and the ground. The switch controller controls a switching operation of a power switch according to the comparison result. The high peak reference and the low peak reference are references for controlling an upper limit and a lower limit of an LED current flowing through the LED string, respectively.

Abstract: The power supply device includes a power switch including one terminal to which an input voltage is transferred; an inductor including one terminal connected to another terminal of the power switch; a diode connected between a ground and a floating ground; a sensing resistor connected between the floating ground and the one terminal of the inductor. A switch controller compares a modulation sensing voltage depending on a sensing voltage generated from the sensing resistor with a high peak reference and a low peak reference when a LED string is connected between an inductor and the ground. The switch controller controls a switching operation of a power switch according to the comparison result. The high peak reference and the low peak reference are references for controlling an upper limit and a lower limit of an LED current flowing through the LED string, respectively.

Abstract: The power supply device includes a power switch including one terminal to which an input voltage is transferred; an inductor including one terminal connected to another terminal of the power switch; a diode connected between a ground and a floating ground; a sensing resistor connected between the floating ground and the one terminal of the inductor. A switch controller compares a modulation sensing voltage depending on a sensing voltage generated from the sensing resistor with a high peak reference and a low peak reference when a LED string is connected between an inductor and the ground. The switch controller controls a switching operation of a power switch according to the comparison result. The high peak reference and the low peak reference are references for controlling an upper limit and a lower limit of an LED current flowing through the LED string, respectively.