US 2014/0193164 A1Published application

Optical receiving circuit

AssigneeFujitsu Limited

InventorSatoshi IDE

Life of this patent

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Abstract

An optical receiving circuit includes: a first non-feedback amplifier configured to convert a current signal, obtained from a light receiving element in response to an optical signal, into a first voltage signal; a second amplifier configured to convert an input current signal into a second voltage signal, the output signal not being directly fed back to an input side; a differential amplifier configured to perform differential amplification on the first voltage signal and the second voltage signal and to output an in positive signal and a negative signal obtained through the differential amplification; and an offset compensation circuit configured to input, on the basis of the in positive signal and the negative signal output from the differential amplifier, an offset current signal in accordance with an offset of a level of the in positive signal from a level of the negative signal to the second amplifier.

Claims13

Dependent claims

An optical receiving circuit, comprising:

a first amplifier configured to convert a current signal, which is input at an input side of the first amplifier and which is a result of a reception, performed by an optical receiving element, of an optical signal, into a voltage signal and to output the voltage signal, the output signal not being directly fed back to the input side of the first amplifier;
a second amplifier configured to convert a current signal, which is input at an input side of the second amplifier, into a voltage signal and to output the voltage signal, the output signal not being directly fed back to the input side of the second amplifier;
a differential amplifier configured to perform differential amplification on the voltage signal input from the first amplifier and the voltage signal input from the second amplifier and to output an in positive signal and a negative signal obtained through the differential amplification;
and
an offset compensation circuit configured to output to the second amplifier, an offset current signal in accordance with an offset of a level of the in positive signal from a level of the negative signal output from the differential amplifier.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/092,125Filed 27 Nov 2013
Priority: JP 2013-00276710 Jan 2013
Published: 10 Jul 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04B 10/6933
Arrangements for optimizing the preamplifier in the receiver: offset control of the differential preamplifier
H03F 3/45103
PI types: non-folded cascode stages
H03F 3/45475
Characterised by the way of implementation of the active amplifying circuit in the differential amplifier: using IC blocks as the active…
H04B 10/6931
Arrangements for optimizing the preamplifier in the receiver: automatic gain control of the preamplifier

Family

US 9,025,971 B2Related patent
US 2014/0193164 A1This patent

From the US filing history. Foreign family members aren’t listed.

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