摘要 |
According to a level of an input signal, first switching means performs control in such a way that only a first feedback resistor or the first and second feedback resistors become feedback resistors connected to amplifying means, and thereby allows the amplifying means to keep linearity without saturating even when the level of the input signal changes. Furthermore, when the input signal has a higher level than a predetermined threshold, a phase compensation capacitor is charged under the control of second switching means for phase compensation of the amplifying means. However, even when the input signal has a lower level than the predetermined threshold, the phase compensation capacitor is charged at predetermined timing under the control of third switching means, preventing a high current from being pulled into the amplifying means when the input signal changes from a lower level than the predetermined threshold to a higher level than the predetermined threshold, thereby reducing noise applied to an output signal.
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