| 摘要 |
PURPOSE:To provide a lighting element driving circuit which enables high-speed operation by removing the overshoot occurring at the starting time of a driving current without elongating the rise time and the trail time, concerning the driving circuit of a light emitting element used for optical communication. CONSTITUTION:In a light emitting element driving circuit which drives a light emitting element 100 by letting a current flow to the light emitting element 100 by a differential signal, being composed of a constant current transistor 400 and differential transistors 200 and 300, a bias circuit 700, which lets the ingredients of overshoot contained in a driving current IL flow being bypassed, is provided, in parallel with the differential transistors 200 and 300, between the source and earth potentials of differential transistors 200 and 300. Furthermore, a bypass current control circuit 800 is provided, which receives one side of differential signals and outputs a control signal for controlling the bypass current flowing in the bypass circuit 700. |
