PURPOSE: To remove waveform distortion in a low frequency range by providing an attenuator which attenuates the input signal from the input terminal of a 1st sampling gate, applying the output of a buffer amplifier and the output of the attenuator to a differential amplifier, and applying the difference signal to a 2nd sampling gate.
CONSTITUTION: The input signal which is applied to the input terminal of the 1st sampling gate 11 is inputted to the buffer amplifier 21 through a parallel circuit of a resistance R6, a resistance R5, and a capacitor C5. The input signal is further passed through the resistance R6, attenuated by the attenuator 19, and then applied to the minus-side terminal of the differential amplifier 22. The output of the buffer amplifier 21 is applied to the plus-side terminal of the differential amplifier 22 and the difference from the signal from the attenuator 19 is calculated, and applied to the 2nd sampling gate 24 and sampled. The resistance 6 reduces the load effect of the capacitor C5 and the input capacitance of the attenuator to a signal source 10.
KUNITO NOBUYUKI
HAMAZAKI MITSUO
KOBAYASHI KENSUKE
