LED DRIVE CIRCUIT, SEMICONDUCTOR ELEMENT, AND IMAGE DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an LED drive circuit which can be driven with a constant current by suppressing an increase in a mounting area even when a large current is flown in an LED array, and which is effective not only in steady operation but also in digital-dimming.

SOLUTION: The LED drive circuit 1 for driving the LED array 100 includes: n constant current drive elements 50 of a vertical structure, which are connected to respective LED strings in series and drive the respective LED strings with the constant current; n constant current control circuits 60 for controlling on-voltages of the respective constant current drive elements 50 so that the currents flowing in the respective LED strings become a constant current; a minimum voltage detection circuit 30 for selecting a minimum voltage out of respective terminal voltages by using the respective terminal voltages of LED string sides of the respective constant current drive elements 50 as inputs, and for outputting a command signal 80 based on a difference between the minimum voltage and a predetermined set voltage; and a power supply control circuit 20 for controlling an applied voltage to the LED array 100 to be a voltage smaller than an initial set voltage based on the command signal 80.

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