| 摘要 |
PURPOSE:To decrease easily transmission signal distortion in case of an optical analog transmission, by applying a negative feedback to compensate the deteriorated linearity between a light emitting element and a photodetector by use of another set of light emitting element and photodetector having the same type. CONSTITUTION:An analog signal inputted to an input terminal 9 and an output voltage of the photodetector 16 adjusted for the amplitude by a feedback amount adjusting circuit 17 are amplified of the error component of two signals at an error amplifier circuit 10 and applied to a driving circuit 11. Thus, the illumination of the light emitting element 13 and the photodetector 12 is changed in accordance with the output amplitude of the error amplifier circuit 10. The light emitted from the light emitting element 13 is transmitted to the photodetector 16, where the light is converted into a voltage. The light emitted from the light emitting element 12 is transmitted to the photodetector 15 through a transmission line 14 and converted into a voltage at the photodetector 15, and amplified at an amplifier circuit 18 and outputted to an output terminal 19. |
