Amplifier circuit and optical pickup device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiroshi Yamaguchi, Shinichi Miyamoto, Tetsuo Chato, Yasufumi Shirakawa, Yuzo Shimizu
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Abstract
An amplifier circuit according to the present invention includes: a first operational amplifier having a negative input terminal, a positive input terminal, and an output terminal; a photodiode connected to the negative input terminal; a first resistor inserted between the output terminal and the negative input terminal; and a second resistor inserted between the output terminal and the positive input terminal, in which the amplifier circuit outputs current from the output terminal via the second resistor.
Claims11
An amplifier circuit, comprising:
- a first operational amplifier including a negative input terminal, a positive input terminal, and an output terminal;
- a photodiode connected to the negative input terminal;
- a first resistor inserted between the output terminal and the negative input terminal;
- a second resistor inserted between the output terminal and the positive input terminal;
- and
- a current buffer circuit to which current outputted from the output terminal of said first operational amplifier via said second resistor is inputted, wherein said first operational amplifier circuit outputs current from the output terminal via said second resistor, said current buffer circuit including a bias circuit, which sets a bias voltage to an output signal line for outputting current from the output terminal of said first operational amplifier via said second resistor.
An amplifier circuit, comprising:
- a first operational amplifier including a negative input terminal, a positive input terminal, and an output terminal;
- a photodiode connected to the negative input terminal;
- a first resistor inserted between the output terminal and the negative input terminal;
- a second resistor inserted between the output terminal and the positive input terminal;
- and
- a current buffer circuit to which current outputted from the output terminal of said first operational amplifier via said second resistor is inputted, wherein said first operational amplifier circuit outputs current from the output terminal via said second resistor, said first operational amplifier circuit further including plural capacitive elements for phase compensation, and
- the first switch circuit switches one of the capacitive elements in conjunction with the switching of the resistance element.
Dependencies are inferred from the claim text.