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Title:
AMPLIFIER OF OPTICAL RECEIVER
Document Type and Number:
Japanese Patent JP2010178256
Kind Code:
A
Abstract:

To provide an amplifier having both initial response speed characteristics and stability characteristics.

A part of a current signal obtained by photoelectric conversion by a PD 111 is subtracted by a current source 112 and the residue is input into an amplifier 120. In the amplifier 120, an impedance conversion amplifier 121 converts the current signal into a voltage signal, and an amplifier 123 amplifies the voltage signal. A signal detector 124 detects the presence or absence of the voltage signal, and an automatic offset compensation circuit 125 integrates the voltage signal. If it is detected that the voltage signal is not present, the automatic offset compensation circuit 125 integrates the signal at a small time constant, and if it is detected that the voltage signal is present, the automatic offset compensation circuit 125 integrates the signal at a large time constant. A subtracting amount by the current source 112 is controlled depending on an output (integration value) of the automatic offset compensation circuit 125.


Inventors:
NISHIHARA SUSUMU
NAKAMURA MAKOTO
NISHIMURA KAZUYOSHI
TOBAYASHI MASATOSHI
ENDO MASAHIRO
Application Number:
JP2009021252A
Publication Date:
August 12, 2010
Filing Date:
February 02, 2009
Export Citation:
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Assignee:
NIPPON TELEGRAPH & TELEPHONE
NTT ELECTRONICS CORP
International Classes:
H04B10/27; H03F3/08; H03F3/34; H04B10/272; H04B10/40; H04B10/50; H04B10/524; H04B10/54; H04B10/564; H04B10/58; H04B10/60; H04B10/69
Domestic Patent References:
JP2009135849A2009-06-18
JP2000068945A2000-03-03
JP2003318997A2003-11-07
JP2005197881A2005-07-21
JP2003317295A2003-11-07
JPH06350463A1994-12-22
Foreign References:
WO2008075430A12008-06-26
Attorney, Agent or Firm:
Toshiro Mitsuishi
Yasuyuki Tanaka
Hiroshi Matsumoto