| 摘要 |
PURPOSE:To provide the light signal receiving circuit which has high sensitivity, generates no noise in the absence of a signal, and can regenerates a light signal from the time of the absence of signals. CONSTITUTION:The light signal receiving circuit consists of a photodiode 11, an amplifier 12 which amplifies the current signal of this photodiode 11, a 1st peak value detecting circuit 13 which detects the peak value of the output signal of the amplifier 12, a couple of resistances 17 and 18 which are connected in series between the output terminal of the 1st peak value detecting circuit 13 and the output terminal of the amplifier 12 and have mutually equivalent resistance values, a 2nd peak value detecting circuit 19 which detects the peak value of a signal at the series connection point between said couple of resistances 17 and 18 on the basis of the output signal of the amplifier 12, an offset voltage generating circuit 22 which supplies a specific offset voltage to the 2nd peak value detecting circuit 19, and a comparator 23 which compares the output voltages of the 1st and 2nd peak value detecting circuits 13 and 19 with each other. |
