| 摘要 |
PURPOSE:To give a high linear characteristic, to hold a high speed responsiveness, and to attain the integration of all circuits on the same circuit board by providing a signal amplifier circuit which consists of the first and the second source followers, a differential amplifier circuit, and a clamping circuit. CONSTITUTION:The titled device is constituted so that a new source insertion resistor R0 is inserted to the output follower resistor of a dummy source follower circuit 3 which gives a reference potential on a differential amplifier circuit 4, and a field through level lower than a level outputted from a signal detecting source follower circuit 2 is outputted. Also, as the resistor R0 and load resistors R1 and R2 for the circuit 4, a semiconductor layer resistor with high resistance formed in the same impurity density as an N-type well area in the embedded channel of a CCD charge element is used. In such a constitution, the reference potential with a low level is given to an input side at the amplifier 4 from the circuit 2, and an input amplitude possible to amplify is expanded. Also, the high speed responsiveness is held, and it is possible to integrate all of the circuits from an optical sensor image pickup circuit 1 to a clamping circuit 5 on a common circuit board 6.
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