| 摘要 |
<p>PURPOSE: An LED drive integrated circuit is provided to directly drive an LED through an isolation transformer by controlling first power factor correction output voltage. CONSTITUTION: A frequency duty controller(620) receives a current of an LED and executes duty control in order to form an output of a transformer having constant voltage. A frequency controller(630) receives the current of the LED and executes frequency control in order to form the output of the transformer having the constant voltage. An oscillator(610) oscillates according to an output signal of the frequency duty controller and frequency controller. An integrated circuit rectifies an AC power source. The integrated circuit switches the rectified AC power source to the transformer by a switching part. The integrated circuit rectifies both ends output of the transformer. The integrated circuit directly drives the LED by using a signal of a square wave shape.</p> |
