| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a current driving circuit capable of generating a high-accuracy driving current. <P>SOLUTION: A voltage-current converting circuit 16 converts an intermediate voltage Vm into a driving current I<SB>LED</SB>proportional thereto. A first resistor R1 is provided between one terminal of a first transistor M1 and a ground terminal. A second resistor R2 and a third resistor R3 are provided in series on a path in parallel with the first resistor R1. In a first operational amplifier OA1, the intermediate voltage Vm is applied to its first input terminal, a voltage at a connecting point of the second resistor R2 and the third resistor R3 is applied to its second input terminal, and its output terminal is connected to a control terminal of the first transistor M1. A first current mirror circuit CM1 returns a current which flows to the first transistor. A second current mirror circuit CM2 returns an output current of the first current mirror circuit CM1 and generates the driving current I<SB>LED</SB>. The second resistor R2 and the third resistor R3 are configured to adjust a potential dividing ratio therebetween. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
