| 摘要 |
PURPOSE:To reduce the stray capacitance on an output terminal by providing an operational amplifier having a feedback capacitor possible for resetting to an output signal extracting circuit. CONSTITUTION:An output line 37 of a photosensing array is connected to an inverting input of the operational amplifier 50. A reference potential VREF is connected to a non-inverting input of the operational amplifier 50. A feedback capacitor 52 is connected directly between the output of the operational amplifier 50 and the inverting input. An FET53 has a channel shunting the capacitor 52. The 2nd capacitor 54 formed by connecting the source and drain of the FET is connected between the inverting input of the amplifier 50 and the source of an inverted RESET signal. Every time a pulse is given to an output line 37, the pulse is integrated by the feedback capacitor 52. The feedback capacitor 52 is reset after each integration period. The 2nd capacitor 54 compensates a switching transient phenomenon.
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