Invention Grant
- Patent Title: Extracting an embedded DC signal to provide a reference voltage for an optical receiver
-
Application No.: US15204372Application Date: 2016-07-07
-
Publication No.: US09819421B1Publication Date: 2017-11-14
- Inventor: Jingqiong Xie , Ashok V. Krishnamoorthy , Xuezhe Zheng , Jeffrey W. Denq , Kannan Raj , John E. Cunningham , Hiren D. Thacker
- Applicant: Oracle International Corporation
- Applicant Address: US CA Redwood Shores
- Assignee: Oracle International Corporation
- Current Assignee: Oracle International Corporation
- Current Assignee Address: US CA Redwood Shores
- Agency: Park, Vaughan, Fleming & Dowler LLP
- Main IPC: H04B10/69
- IPC: H04B10/69

Abstract:
An optical receiver includes: an active transimpedance amplifier (TIA) that converts a photocurrent from a photosensor into an active voltage signal; a high-speed amplifier that amplifies the active voltage signal to produce an amplified voltage signal that comprises an output for the optical receiver; and a reference-voltage-generation circuit that generates a reference voltage for the high-speed amplifier. This reference-voltage-generation circuit includes a dummy TIA that is identical to the active TIA, but does not receive a live input signal, and produces a dummy voltage signal. It also includes a low-speed amplifier which includes: an active input that receives the active voltage signal from the active TIA output; a dummy input that receives the dummy voltage signal from the dummy TIA output; and an output that controls directly or indirectly the reference voltage for the high-speed amplifier. In the direct control case, the output of low-speed amplifier includes a feedback connection that feeds back into the dummy input. In the indirect control case, the output of low-speed amplifier adjusts the reference voltage for the high-speed amplifier through dummy TIA internal biasing.
Information query