| 摘要 |
There is intended to provide a current-voltage converter capable of surely outputting a voltage output signal regardless of current intensity when converting a current input signal with wide current range into a voltage output signal. In case a current value of a current input signal Iin is small, small current regions of diodes D10 1 and D102 are used and current values of first bias currents IB1 and IB2 are set small. Thereby, the small current regions can be used as a region to deal with a large change rate of voltage against current and there can be obtained an effective voltage change even for a micro current. In case a current value of the current input signal Iin is large, current values of bias currents IB1 and IB2 at a constant current circuit 13 increase to a second bias current to obtain a characteristic such that conversion voltage VM and reference voltage VP are compressed against the current input signal Iin. To obtain the compression characteristics, there is made used of a characteristic of the diodes D101 and D102 such that their terminal-to-terminal voltage against current increases monotonously forming a convex shape. Thereby, output voltage can keep compressed differential voltage in a wide current range. Accordingly, a differential amplifier circuit AMP101 does not need to change its dynamic range.
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