Electronic device, fiber-optic communication system comprising the electronic device and method of operating the electronic device

摘要

An electronic device, a fiber-optic communication system comprising the electronic device and a method of operating the electronic device are provided. The electronic device comprises a transimpedance-type amplifier having a transimpedance stage comprising an amplifier which is coupled in series with an input node. A feedback resistor is coupled in series between an output node of the amplifier and an inverting input node of the amplifier to provide a virtual ground node which is coupled to the input node, the inverting input node of the amplifier and to the feedback resistor. A current source is coupled to the virtual ground node so as to compensate for an offset current in an input signal which is coupled to the input node of the electronic device. Further, the electronic device comprises a control stage which is configured to control the current source as a function of a current through the feedback transistor.

主权项

1. An electronic device comprising
a transimpedance-type amplifier having a transimpedance stage comprising an amplifier which is coupled in series with an input node of the electronic device, wherein a feedback resistor is coupled in series between an output node of the amplifier and an input node of the amplifier so as to provide a virtual ground node which is coupled to the input node of the electronic device, to the input node of the amplifier and to the feedback resistor, wherein a current source is coupled to the virtual ground node so as to compensate for a direct current component in an input signal which is coupled to the input node of the electronic device, and wherein the electronic device further comprises an offset cancellation stage which is configured to control the current source as a function of a current through the feedback resistor, wherein the transimpedance-type amplifier stage is configured to draw a DC offset current from the input node of the electronic device, wherein the transimpedance-type amplifier stage comprises a bipolar transistor having a base which is coupled to the virtual ground node, wherein the DC offset current is a base current of the bipolar transistor which is drawn from the input node of the electronic device.