| 摘要 |
PURPOSE:To provide a semiconductor laser driving circuit capable of suppressing the increase of the overshoot and the undershoot of a semiconductor laser driving current. CONSTITUTION:Switching circuits S1, S2 and S3, S4 are respectivley connected to first and second pulse current driving circuits 4 and 5 which respectively incorporate constant current circuits 2 and 3. Write data D1 and D2 which are delayed by a delay line 8 are applied to the control terminals of the circuits S3 and S4 slow in switching speed through a buffer 9, etc. Thus, even through the overshoot and the undershoot are generated in the first driving current associated with the ON/OFF of circuits S1 and S2 high in switching speed, these are added with the second driving currents of the slow-speed switching circuits S3 and S4 and are supplied to a semiconductor laser 6. Therefore, a driving current suppressed in overshoots and undershoots can be supplied. |
