Patent ID: 8582985

Claim:
An optical receiver, comprising: an optical-to-electrical (OE) converter configured to receive an optical signal and to provide an analog electrical signal; a transimpedance amplifier (TIA), electrically coupled to the OE converter, having a normal mode and a calibration mode, wherein the TIA includes an amplifier; a decision circuit, electrically coupled to the TIA, configured to determine a digital electrical signal from the analog electrical signal; and control logic, electrically coupled to the TIA, configured to provide a signal that specifies an operating mode of the TIA, wherein the operating mode is one of the normal mode and the calibration mode; wherein, during the normal mode, the TIA is configured to electrically couple an input of the TIA to the OE converter; wherein, during the calibration mode, the TIA is configured to electrically isolate the input of the TIA from the OE converter while maintaining a feedback path from an output of the TIA to an input of the TIA, thereby ensuring proper bias of the TIA during calibration; and wherein a frequency response of the TIA during the normal mode is substantially unchanged over an operating bandwidth of the TIA by the capability to electrically isolate the input of the TIA from the OE converter during the calibration mode.