Invention Grant
US07868702B2 Photoreceiver/amplifier circuit, optical pickup device, and optical disk device
有权
光接收器/放大器电路,光学拾取装置和光盘装置
- Patent Title: Photoreceiver/amplifier circuit, optical pickup device, and optical disk device
- Patent Title (中): 光接收器/放大器电路,光学拾取装置和光盘装置
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Application No.: US11861819Application Date: 2007-09-26
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Publication No.: US07868702B2Publication Date: 2011-01-11
- Inventor: Masaya Ohnishi
- Applicant: Masaya Ohnishi
- Applicant Address: JP Osaka-shi
- Assignee: Sharp Kabushiki Kaisha
- Current Assignee: Sharp Kabushiki Kaisha
- Current Assignee Address: JP Osaka-shi
- Agency: Morrison & Foerster LLP
- Priority: JP2006-263542 20060927; JP2007-181433 20070710
- Main IPC: H03F3/08
- IPC: H03F3/08

Abstract:
The subject invention provides a photoreceiver/amplifier circuit comprising a differential circuit including a differential transistor pair and a bias circuit; an active load; a feedback resistor for converting a photocurrent generated from a photodiode into a voltage; a reference resistor; and a compensation circuit. The resistance of the feedback resistor is greater than the resistance of the reference resistor. The compensation circuit supplies a compensation current from a junction between the feedback resistor and a non-inverting input terminal of the differential amplifier circuit, so as to cancel the difference between a voltage between terminals of the feedback resistor and a voltage between terminals of the reference resistor. This reduces noise and improves offset voltage characteristics. The present invention provides a photoreceiver/amplifier circuit ensuring noise reduction and desirable offset voltage characteristics.
Public/Granted literature
- US20080074198A1 PHOTORECEIVER/AMPLIFIER CIRCUIT, OPTICAL PICKUP DEVICE, AND OPTICAL DISK DEVICE Public/Granted day:2008-03-27
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