| 摘要 |
PROBLEM TO BE SOLVED: To obtain a laser diode drive circuit which corrects a finite difference between a target current value generated by variation of a power source voltage or a channel length modulation effect and a current value to be actually supplied to a laser diode, and which can supply a current close to the target value to the laser diode. SOLUTION: A forward voltage VLD1 as the reference of a laser diode LD in accordance with a current i1 is generated by a first current mirror value 3 at a high accuracy and a first dummy laser diode LD1 in which a resistance value and/or a forward voltage is variably set, and also an actual forward voltage VLD2 of the laser diode LD in accordance with the current i1 is generated by a second current mirror value 4 and a second dummy laser diode LD2 in which the resistance value and/or the forward voltage is variably set, and a current iLD flowing in the laser diode LD is controlled so that the forward voltage VLD2 becomes the forward voltage VLD1 as a reference. COPYRIGHT: (C)2005,JPO&NCIPI
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