Signal amplifier

Abstract

The signal amplifier of this invention includes a noise amplifier that amplifies a difference between a first ground potential and a second ground potential, and an adding amplifier that superposes an analog input signal on an output potential of the noise amplifier, and amplifies a difference between the first ground potential and a potential having the analog input signal and the output potential superposed. Thus, the adding amplifier superposes the noises amplified by the noise amplifier on the analog input signal, and thereafter amplifies the difference between the first ground potential and the potential thus superposed. Thereby, the signal amplifier is able to amplify only the analog input signal, without amplifying the noises of the first ground potential or the second ground potential.

Dependencies are inferred from the claim text.