| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser diode driving circuit high in safety without making excessive current flow through the laser diode even upon sudden current inrush or breakage of a driving element for driving the laser diode. SOLUTION: A DC power supply 1 is connected to one end of a resistor R1, and the other end of the resistor R1 is connected to the anode of a capacitor C and the laser diode 3. The opposite side is grounded at the terminal connected to the resistor R1 between the terminals of the capacitor C. A buffer 2 is connected to the gate of the transistor TR1, and a current limiting resistor R2 is connected between the drain of transistor TR1 and the cathode of laser diode 3. A low pass filter is formed by the resistor R1 and the capacitor C with respect to the power supply line of the DC power supply 1. A DC current flowing through the laser diode 3 is limited by the resistor R1. COPYRIGHT: (C)2006,JPO&NCIPI
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