Ii-vi Delaware, Inc.

Dinup Sukumaran

Richard D Davis

Ken C Kiong

An optical device for optical signals comprises: a photodiode configured to receive the optical signals; and a linear transimpedance amplifier (TIA) having an input stage, an output stage, and at least one variable gain amplifier (VGA) provided between the input stage and the output stage. The optical device also comprises: an automatic gain control loop configured to rectify an output of the at least one VGA and compare the rectified output with a threshold gain setting to generate an automatic gain control voltage; and a detection circuitry being configured to detect a rate of change in the automatic gain control voltage and being configured to determine a first state indicative of an absence of the optical signals at the photodiode. At least in response to the determined first state, the detection circuitry is configured to disable the output stage of the linear TIA.

Control of linear trans-impedance amplifier (TIA) during settling after recovering from loss of signal in receiver

An optical receiver includes a photodiode, a transimpedance amplifier (TIA), a slope detection circuit, and a logic circuit. The TIA includes an output stage and a feedback amplifier and is coupled to the photodiode. The slope detection circuit is coupled to the feedback amplifier and configured to monitor a feedback signal from the feedback amplifier. The slope detection circuit is configured to provide, in response to a slope in the feedback signal being detected, a first slope-status signal indicating the slope is detected. The logic circuit is coupled to the slope detection circuit and is coupled to the output stage of the TIA. The logic circuit is configured to squelch the output stage of the TIA in response to the first slope-status signal.

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Wilmington, DE, United States of America

Dinup Sukumaran