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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHideo Fukuda, Shinichi Miyamoto
Estimating the term…
A differential amplifier circuit, an operational amplifier circuit, and a light-receiving amplifier circuit using the same are provided, by which the influence of an on resistance of an analog switch is reduced during the switching of gain resistances. An NPN transistor Q2 having an emitted connected in common is connected to an NPN transistor Q1 of a differential amplifier circuit including the NPN transistors Q1 and Q3, PNP transistors Q4 and Q5, and a constant-current source 11, and analog switches ASW-1c and ASW-2c are inserted and connected to the collectors of the NPN transistors Q1 and Q2 and connected to the base and collector of the PNP transistor Q4 and the base of the PNP transistor Q5. Further, analog switches ASW-1b and ASW-2b are connected to the bases of the NPN transistors Q1 and Q2, respectively.
A differential amplifier circuit, wherein one input of an input section comprises a plurality of inputs connected in parallel, at least one or more analog switches are connected to each of the plurality of inputs, one of the plurality of inputs is selected by switching the analog switches, and a signal proportionate to a difference between a signal from the one input and a signal from the other input of the input section is outputted.
A differential amplifier circuit, comprising a plurality of input sections connected in parallel, wherein
A differential amplifier circuit, wherein a reference voltage inputted to one of input sections is selected by switching at least one or more analog switches connected to each of a plurality of voltage sources for supplying the reference voltage.
A light-receiving amplifier circuit comprising a plurality of light-receiving elements connected to one input of an operational amplifier circuit, the light-receiving element converting an optical signal to an electrical signal, wherein
A function selection circuit, wherein one of a plurality of functional circuits is selected by switching analog switches respectively connected to the input side and output side of the plurality of functional circuits.
Dependencies are inferred from the claim text.