| 摘要 |
PURPOSE:To keep an output constant and to reduce the danger of a thermorunaway in a light source for optical communication and so on by overshooting to a driving current with a constitution to delay the output monitor signal of a driving device for a fixed time and to execute a negative-feedback. CONSTITUTION:A current corresponding to the difference between a non- inversion input and an inversion input is supplied to an LED 10, and a driving device 11 to output a monitor signal corresponding to the supplied current and a delay device 12 to delay the monitor signal for a fixed time Td and to feed it back to an inversion input terminal 14 are provided. Then, when a rectangular wave type signal is inputted to an input terminal 15, the output of the device 11 rises sharply as indicated in a broken line (a). After that, when the delay time Td passes, since the monitor signal is given to the terminal 14 and is negative-fed back, an output current (the optical output of the LED) is reduced as a waveform (b) and is stable at a fixed value. |
