LED driving device, lighting device, and vehicle-mounted display device

• Main Authors: Katsura, Koji, Kanemitsu, Ryosuke
• Format: Patent
• Language: English
• Published: 06.06.2023
• Subjects: ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING ORSUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES INGENERAL; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PERFORMING OPERATIONS; TRANSPORTING; VEHICLES IN GENERAL

This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.