LED DRIVING CIRCUIT

摘要

PURPOSE: An LED driving circuit is provided to realize a double protection structure of individual over voltage protection and entire over voltage protection, thereby performing entire over voltage protection in case of an error of individual over voltage protection. CONSTITUTION: The first to nth DC/DC converters(10-1~10-n) supply voltages to the first to nth LED groups(LEDG1~LEDGn) respectively. A voltage detecting circuit unit(100) includes the first to nth output voltage detecting units for detecting output voltages of the first to nth DC/DC converters. A high voltage selecting unit(200) selects the maximum detection voltage among the first to nth detection voltages. A comparison unit(300) compares the maximum detection voltage with a preset reference voltage to output a switching signal. A switch(400) is turned on/off by a switching signal of the comparison unit.