Abstract: A dynamic range compression circuit includes an attenuator that attenuates a signal at a predetermined node in an amplifier to reduce a gain of the amplifier and a gain controller that reduces the gain of the amplifier by the attenuator so that an amplitude of an output signal of the amplifier becomes an arbitrary output limit voltage in a case where an input signal having the same amplitude as that of an input-stage maximum voltage of the amplifier is input into the amplifier, and increases the gain of the amplifier by reducing a degree of attenuation of the attenuator according to a decrease of the amplitude of the input signal of the amplifier from the input-stage maximum voltage in a case where the amplitude of the input signal of the amplifier is smaller than the input-stage maximum voltage.

Abstract: A dynamic range compression circuit includes an attenuator that attenuates a signal at a predetermined node in an amplifier to reduce a gain of the amplifier and a gain controller that reduces the gain of the amplifier by the attenuator so that an amplitude of an output signal of the amplifier becomes an arbitrary output limit voltage in a case where an input signal having the same amplitude as that of an input-stage maximum voltage of the amplifier is input into the amplifier, and increases the gain of the amplifier by reducing a degree of attenuation of the attenuator according to a decrease of the amplitude of the input signal of the amplifier from the input-stage maximum voltage in a case where the amplitude of the input signal of the amplifier is smaller than the input-stage maximum voltage.

Abstract: A differential amplifier includes: a constant current source; first and second field effect transistors whose respective gates are imparted with positive-phase and negative-phase input signals and whose sources commonly connected to each other, the constant current source being connected to a common node of the sources; first and second loads serving as current paths for respective drain currents of the first and second field effect transistors; an amplifying unit which outputs positive-phase and negative-phase output signals which are amplified in response to the respective drain voltages of the first and second field effect transistors; and a current path generator which generates first and second current paths parallel to the respective first and second field effect transistors for a predetermined period of time at the time of start-up of the differential amplifier.

Abstract: A differential amplifier includes: a constant current source; first and second field effect transistors whose respective gates are imparted with positive-phase and negative-phase input signals and whose sources commonly connected to each other, the constant current source being connected to a common node of the sources; first and second loads serving as current paths for respective drain currents of the first and second field effect transistors; an amplifying unit which outputs positive-phase and negative-phase output signals which are amplified in response to the respective drain voltages of the first and second field effect transistors; and a current path generator which generates first and second current paths parallel to the respective first and second field effect transistors for a predetermined period of time at the time of start-up of the differential amplifier.