Patent ID: 8558479

Claim:
An LED driver comprising: a voltage step-up and -down DC/DC converter controller block which controls a voltage step-up and -down DC/DC converter that generates from an input voltage an output voltage and feeds the output voltage to an LED; and a current driver block which generates an output current of the LED, wherein the voltage step-up and -down DC/DC converter comprises: a first switch of which a first terminal is connected to an application terminal of the input voltage; a first diode of which a cathode is connected to a second terminal of the first switch and of which an anode is connected to a ground terminal; an inductor of which a first terminal is connected to the second terminal of the first switch; a second switch of which a first terminal is connected to a second terminal of the inductor and of which a second terminal is connected to the ground terminal; and a second diode of which an anode is connected to the second terminal of the inductor and of which a cathode is connected to an anode of the LED.