| 摘要 |
PROBLEM TO BE SOLVED: To obtain a device capable of holding linearity even when a reset signal is overlapped with an input signal by selecting a regulated feedback resistor and a feedback resistor for gain control and connecting the feedback resistor for gain control with the regulated feedback resistor in parallel when an externally supplied reset signal is inputted as inputting such a large input signal to saturate a current voltage conversion amplifier circuit. SOLUTION: The input signal is amplified as converting it into voltage via the regulated feedback resistor 2 and the feedback resistor 3 for gain control by the current voltage conversion amplifier circuit 1. When the input signal with an input level equal to or less than an output amplitude level by which the amplifier circuit 1 is saturated or the externally supplied reset signal is inputted in the amplifier circuit 1, the regulated feedback resistor 2 is selected. And the input signal larger than the output amplitude level by which the amplifier circuit 1 is saturated is inputted as the input level, the regulated feedback resistor 2 and the feedback resistor 3 for gain control are selected and a gain of the amplifier circuit 1 is lowered.
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