LED driving device and LED lighting device including the same

An LED driving method of an LED driving device in which an IC heat dissipation part is connected between an LED string and a current controller comprising:

• detecting an LED voltage from a node between the LED string and the IC heat dissipation part;
• checking whether the detected LED voltage increases;
• controlling an LED current such that the LED current of the LED string is switched from a first path flowing from the LED string to the current controller to a second path flowing from the LED string to the current controller via the IC heat dissipation part when the LED voltage increases;
• and
• reducing IC heat generation of the current controller when the LED current flows through the second path,
• wherein the current controller includes:
• a first switching part that has one side connected to a node between the LED string and the IC heat dissipation part to form the first path through which the first LED current flows;
• and
• a second switching part that has one side connected to the IC heat dissipation part to form the second path through which the second LED current flows, and
• wherein a first output voltage provided to the first switching part and a second output voltage provided to the second switching part are different from each other so as to adjust a resistance difference between the first switching part and the second switching part.

An LED lighting device comprising:

• an LED string to which a plurality of LEDs are connected;
• a battery configured to supply a voltage to the LED string;
• a current controller configured to constantly control an LED current flowing through the LED string;
• and
• an IC heat dissipation part connected to a node between the LED string and the current controller to dissipate IC heat of the current controller,
• wherein when the battery voltage supplied to the LED string increases, a first LED current flowing from the LED string to the current controller is decreased and simultaneously a second LED current flowing from the LED string to the current controller via the IC heat dissipation part is increased to reduce IC heat generation of the current controller,
• wherein the current controller includes:
• a first switching part that has one side connected to a node between the LED string and the IC heat dissipation part to form a first path through which the first LED current flows;
• and
• a second switching part that has one side connected to the IC heat dissipation part to form a second path through which the second LED current flows, and
• wherein a first output voltage provided to the first switching part and a second output voltage provided to the second switching part are different from each other so as to adjust a resistance difference between the first switching part and the second switching part.