RECEIVING CIRCUIT

• Main Authors: SUGIMOTO YOSHIYUKI, TANAKA KEIJI
• Format: Patent
• Language: English; Japanese
• Published: 03.04.2023
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

To provide a receiving circuit that is suppressed in deterioration in noise characteristics thereof within a range of small input current, and furthermore can suppress increase in offset of a differential signal.SOLUTION: A receiving circuit comprises: a first transimpedance amplifier that receives a first input current and outputs a first voltage; a second transimpedance amplifier that receives a second input current and outputs a second voltage; a first reference voltage circuit that generates a first reference voltage depending on a first feedback current; a second reference voltage circuit that generates a second reference voltage depending on a third feedback current; first and second offset control circuits; and a differential amplifier circuit that outputs a differential signal depending on the first and second voltages. The first offset control circuit adjusts the first feedback current depending on an average voltage value of the first voltage, or alternatively, subtracts a second feedback current from the first input current. The second offset control circuit adjusts the third feedback current depending on an average voltage value of the second voltage, or alternatively, subtracts a fourth feedback current from the second input current.SELECTED DRAWING: Figure 1 【課題】入力電流値が小さい範囲での雑音特性の劣化を抑制しつつ、差動信号のオフセットの増加を抑制可能な受信回路を提供する。【解決手段】受信回路は、第１入力電流を受け、第１電圧を出力する第１トランスインピーダンスアンプと、第２入力電流を受け、第２電圧を出力する第２トランスインピーダンスアンプと、第１帰還電流に応じて第１参照電圧を生成する第１参照電圧回路と、第３帰還電流に応じて第２参照電圧を生成する第２参照電圧回路と、第１および第２オフセット制御回路と、第１および第２電圧に応じて差動信号を出力する差動増幅回路を有する。第１オフセット制御回路は、第１電圧の平均電圧値に応じて第１帰還電流を調整し、または第１入力電流から第２帰還電流を減算する。第２オフセット制御回路は、第２電圧の平均電圧値に応じて第３帰還電流を調整し、または第２入力電流から第４帰還電流を減算する。【選択図】図１