Light-emitting diode illumination device

An LED lighting apparatus comprising:

• a first LED light source and a second LED light source included in a first light source group;
• a third LED light source and a fourth LED light source included in a second light source group;
• a mode determination unit configured to determine a first mode and a second mode depending on a peak level of a rectified voltage and provide a mode control signal and a current control signal corresponding to a mode, the rectified voltage of the second mode having the peak level higher than the rectified voltage the first mode;
• a current control unit configured to transfer, by the current control signal, the rectified voltage to the second light source group by bypassing the first light source group, during a first period in which the rectified voltage is lower than a preset control level;
• a first balancing circuit configured to be set in a first balancing level to a different level depending on a mode by the current control signal, and transfer the rectified voltage to the second LED light source by bypassing the first LED light source in the case where the rectified voltage is lower than the first balancing level;
• a second balancing circuit configured to be set in a second balancing level to a different level depending on a mode by the current control signal, and transfer the rectified voltage to the fourth LED light source by bypassing the third LED light source in the case where the rectified voltage is lower than the second balancing level;
• and
• a current path providing circuit configured to, in correspondence to the mode control signal, provide, in the first mode, to the first LED light source to the fourth LED light source, a first current path changed in correspondence to light emission of each of the first light source group and the second light source group in which arrangement states of LED light sources therein are changed to series or parallel in correspondence to change of the rectified voltage through one cycle according to turn-on and turn-off of the first balancing circuit and the second balancing circuit, and provide, in the second mode, to the fourth LED light source, a second current path corresponding to light emission of the first LED light source to the fourth LED light source whose serial connection state is changed in correspondence to change of the rectified voltage through one cycle according to sequential turn-off and turn-on of the current control unit, the second balancing circuit and the first balancing circuit.