| 摘要 |
PURPOSE:To reduce the mount area of the circuit and to simplify the mounting when offset compensation and phase compensation of the optical signal reception amplifier are implemented by adding a phase compensation capacitance to a reference input terminal of a main amplifier. CONSTITUTION:Outputs VP1, VP2 of peak detection circuits PD1, PD2 are given to a noninverting input terminal and an inverting input terminal of a DC amplifier circuit DCA. An output subjected to error amplification by the circuit DCA is fed back to a reference input terminal VREF of a main amplifier POST. A phase compensation capacitor C is inserted to a feedback loop FEED BACK so as to provide a pole at an optional point. For example, the capacitor is inserted between a reference input VREF being a high impedance node of the main amplifier POST and ground. Thus, one connection terminal to a chip externally mounted capacitor for phase compensation of the loop is enough, the mount area is reduced and the mounting is simplified. |
