| 摘要 |
PROBLEM TO BE SOLVED: To provide a correlative double sampling circuit for solid-state image pickup element capable of attaining the reduction of production costs and miniaturization. SOLUTION: This correlative double sampling circuit is provided with a charge sensitive amplifier 50 for converting an electric charge signal inputted from a solid-state image pickup element to a voltage, a low-pass filter(LPF)/ amplifier part 11 for removing a noise from the voltage signal and amplifying it, a sample/hold(S/H) part 53 for sampling the amplified voltage signal, an A/D converter 54 for converting the sampled analog signal to a digital signal, and a latch 55. Plural capacitors 5 and 12 are arranged in parallel on the input terminal side of an operational amplifier 8 in the LPF/amplifier part 11 and a connection between the capacitors is changed over by switches 13 and 14. The capacitors 5 and 12 to be changed over by the switches variably determine the time constant of the LPF part and the gain of the amplifier part.
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