| 摘要 |
The present invention relates to a power integrated circuit for LED lighting. When alternating current power is inputted, a rectifier rectifies the alternating current power and outputs direct current power which is not smoothened. PWM control is performed, using a DC/DC converter, on the alternating current power which is not smoothened or on smoothened power, so as to step down a voltage to be suitable for a Vf value of all of the LED groups, respectively. Then, an LED group, which has a Vf value corresponding to the voltage outputted by the DC/DC converter in synchronization with the voltage phases corresponding to each LED Vf value, is selected and turned on. Thus, LEDs for lighting can be driven without using an electrolytic condenser or a transformer used in conventional techniques. As a result, the lifespan of a power integrated circuit for LED lighting is remarkably elongated. In addition, the power integrated circuit of the present invention measures the temperature of a lighting device, and automatically cuts off the current flowing to the LED groups when the measured temperature is higher than a preset temperature level, thus preventing the entirety of the power integrated circuit for LED lighting from being degraded by excessive rises in temperature. |
