| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a light-emitting diode driving circuit that suppresses variation in light-emission luminance of a light-emitting diode. <P>SOLUTION: A reference current part 33 has: an operational amplifier 30 which controls a reference current so that a voltage occurring due to flowing of the reference current in a resistor becomes identical with a fixed reference voltage; and a first current mirror circuit for generating a first current based on the reference current. A current output of each channel has: a second current mirror circuit which is composed together with a part of the reference current part so as to generate a second current based on the first current; and a third current mirror circuit that is supplied with the second current so as to generate a current proportional to the second current corresponding to the turned-on switch among switches of a plurality of systems. Each of the first/second/third current mirror circuits is a two-stage cascade-connected current mirror circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
