| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser diode drive circuit which can supply a current approximated to the target current value to a laser diode by compensating for difference between the target current value and the current value supplied actually to the laser diode generated by variation of power source voltage and channel length modulation effect. SOLUTION: The fourth current mirror circuit 6 supplies respectively the current corresponding to the current i1 outputted from a current source 2 to the first to third current mirror circuits 3 to 5. The high precision first current mirror circuit 3 and the first artificial laser diode LD1 generate the forward voltage VLD1 as the reference voltage of the laser diode LD corresponding to the current i1, and the second current mirror circuit 4 and the second artificial laser diode LD2 generate the actual forward voltage VLD2 of the laser diode LD corresponding to the current i1 in order to control the current iLD flowing into the laser diode LD so that the forward voltage VLD2 becomes the reference forward voltage VLD1. COPYRIGHT: (C)2005,JPO&NCIPI
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