OPTICAL RECEPTION CIRCUIT AND OPTICAL RECEIVER

• Main Authors: KUMAGAI SEIJI, SUGIMOTO YOSHIYUKI
• Format: Patent
• Language: English; Japanese
• Published: 03.06.2021
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; CONTROL OF AMPLIFICATION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

To provide an optical reception circuit and an optical receiver capable of enhancing linearity of a reception signal.SOLUTION: An optical reception circuit comprises: a first input terminal that receives one of a pair of current signals; a second input terminal that receives the other of the pair of current signals; a first FET including a first current terminal electrically connected with the first input terminal, a second current terminal electrically connected with the second input terminal, and a first control terminal receiving a first control signal; a first TIA that receives a part, which remains after exclusion of a part branched to the first FET, of one of the pair of current signals, and generates one of a pair of voltage signals; a second TIA that receives a part, which remains after exclusion of a part branched to the first FET, of the other of the pair of current signals, and generates the other of the pair of voltage signals; and a control circuit that detects a voltage difference between one of the pair of voltage signals and the other of the pair of voltage signals, and reduces a resistance value of the first FET by changing the first control signal when an amplitude of the voltage difference exceeds a prescribed value.SELECTED DRAWING: Figure 1 【課題】受信信号の線形性を高めることができる光受信用回路および光受信器を提供する。【解決手段】光受信用回路は、一対の電流信号の一方を受ける第１入力端子と、一対の電流信号の他方を受ける第２入力端子と、第１入力端子と電気的に接続される第１電流端子、第２入力端子と電気的に接続される第２電流端子、及び第１制御信号を受ける第１制御端子を有する第１ＦＥＴと、一対の電流信号の一方のうち第１ＦＥＴへ分流した一部を除く残部を受けて、一対の電圧信号の一方を生成する第１ＴＩＡと、一対の電流信号の他方のうち第１ＦＥＴへ分流した一部を除く残部を受けて、一対の電圧信号の他方を生成する第２ＴＩＡと、一対の電圧信号の一方と一対の電圧信号の他方との電圧差を検出し、電圧差の振幅が所定の値より大きくなったときに第１制御信号を変化させて第１ＦＥＴの抵抗値を小さくする制御回路とを備える。【選択図】図１