Light-emitting driving device and a backlight apparatus

A light-emitting driving device, comprising:

• a driving current generation circuit configured to be connected to a channel terminal of a light-emitting string comprising a plurality of semiconductor light-emitting elements to generate a driving current supplied to the channel terminal;
• a first switching element between the channel terminal and the driving current generation circuit;
• a sensing circuit configured to be connected to the channel terminal and configured to sense a voltage of the channel terminal;
• a second switching element between the channel terminal and the sensing circuit;
• a PWM signal generation circuit configured to generate a PWM signal that controls on and off of the first switching element and the second switching element;
• and
• a controller configured to be connected to the sensing circuit and configured to control at least one or more of an intensity of the driving current and a duty ratio of the PWM signal based on the sensed voltage of the channel terminal.

A backlight apparatus, comprising:

• a backlight substrate comprising a plurality of light-emitting strings connected to a plurality of channel terminals, each the plurality of light-emitting strings comprising a plurality of semiconductor light-emitting elements;
• and
• a plurality of light-emitting driving circuits configured to be connected to the plurality of channel terminals to drive the plurality of light-emitting strings,
• wherein each of the plurality of light-emitting driving circuits comprises:
• a driving current generation circuit configured to generate a driving current supplied to the channel terminal;
• a sensing circuit configured to be connected to the channel terminal and configured to sense a voltage of the channel terminal;
• a PWM signal generation circuit configured to generate a PWM signal that controls supply of the driving current;
• and
• a controller configured to be connected to the sensing circuit and configured to control at least one or more of an intensity of the driving current and a duty ratio of the PWM signal based on the sensed voltage of the channel terminal,
• wherein when the sensed voltage of the channel terminal exceeds a reference voltage, the controller is configured to control the driving current generation circuit to increase the intensity of the driving current, and
• wherein the reference voltage is a value greater than a minimum headroom voltage corresponding to a lower limit of a headroom voltage coverage.