| 摘要 |
<p>First and second peak detectors (12, 13) detect the respective peak values of the positive-phase and negative-phase outputs of a first differential amplifier (11) for amplifying the input signal and hold them. A second differential amplifier (14) amplifies the difference between the outputs of the peak detectors (12, 13). The positive-phase and negative-phase outputs of the second differential amplifier (14) agree with the middle values of the positive-phase and negative-phase outputs of the first differential amplifier (11). A composite differential amplifier (15) amplifies the differential component {(VS1-VR1)-(VS2-VR2)} between the differential component (VS1-VR1) between the positive-phase output (VS1) of the first differential amplifier (11) and the positive-phase output (VR1) of the second differential amplifier (14) and the differential component (VS2-VR2) between the opposite-phase component (VS2) of the first differential amplifier (11) and the opposite-phase output (VR2) of the second differential amplifier (14). Preferably, the output value of the first differential amplifier (11) at the time of no input is the same as that of the second differential amplifier (14) at the time of no input.</p> |
