| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an LED control circuit for fading out LEDs according to a lights-out start signal from the outside and turning off current flowing through the LEDs reliably when the fade-out is completed. <P>SOLUTION: A command value outputting circuit 10 outputs a digital current command value for indicating a drive current to be supplied to an LED 1. A drive current supply circuit 20 supplies a drive current according to the current command value to the LED 1. A switch circuit 30 turns on/off the supply of the drive current to the LED 1. A determination circuit 40 determines whether the current command value is equal to or smaller than a prescribed value. When a lights-out start signal for instructing the start of the lights-off of the LED 1 is inputted from the outside in this configuration, the command value outputting circuit 10 decreases the current command value gradually. Then, when the determination circuit 40 determines that the current command value is equal to or smaller than a prescribed value, the switch circuit 30 turns off the supply of the drive current to the LED 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
