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
  • Application No.: US11861819
    Application Date: 2007-09-26
  • Publication No.: US07868702B2
    Publication 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
Photoreceiver/amplifier circuit, optical pickup device, and optical disk device
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.
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