| 摘要 |
<P>PROBLEM TO BE SOLVED: To make an LED current constant while reducing the cost required for an LED lighting circuit. <P>SOLUTION: An LED lighting circuit 50 raises a power supply voltage supplied from a power supply circuit 60 by the control of a driver IC (Integrated Circuit) to generate a power supply voltage required for lighting an LED (Light Emitting Diode) 40. In the LED lighting circuit 50, the driver IC is eliminated, and the power supply circuit 60 is integrated with the LED lighting circuit 50. The LED lighting circuit 50 has a feedback circuit 54 detecting an LED current flowing in the LED 40 to feed it back to the power supply circuit 60. The power supply circuit 60 controls the power supply voltage to be supplied to the LED lighting circuit 50 so that the LED current converges to a target value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
