Light emitting diode driving apparatus

A light emitting diode driving apparatus, comprising:

• a power supplying unit converting input power into driving power according to control and supplying the converted driving power to a light emitting diode channel;
• a driving unit controlling current flowing in the light emitting diode channel according to a pulse width modulation (PWM) dimming signal from the outside;
• and
• a controlling unit comparing a reference level set by a duty of the PWM dimming signal with a detection voltage level of the light emitting diode channel and controlling a power converting operation of the power supplying unit according to the comparison result,
• wherein the controlling unit includes:
• a PWM duty sensing unit sensing the duty of the PWM dimming signal;
• a reference level changing unit changing the reference level when the duty of the PWM dimming signal sensed by the PWM duty sensing unit is shorter than a preset reference duty;
• a comparing unit comparing the reference level from the reference level changing unit with the detection voltage level of the light emitting diode channel;
• and
• a power controlling unit controlling the power converting operation of the power supplying unit according to the comparison result of the comparing unit,
• wherein the light emitting diode channel comprises a plurality of light emitting diode channels connected to each other in parallel,
• wherein the driving unit includes a plurality of drivers corresponding to the plurality of light emitting diode channels, respectively, and
• wherein each of the plurality of drivers includes:
• a switch connected between an end of the corresponding light emitting channel and a ground and controlling the current flowing in the light emitting diode channel according to a switching signal;
• and
• a comparator comparing the PWM dimming signal from the outside with voltage obtained by detecting the current flowing in the switch and controlling a switching operation of the switch.