Extracting an embedded DC signal to provide a reference voltage for an optical receiver
US9819421B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 2016 |
| Grant date | Nov 14, 2017 |
| Priority date | — |
| Expiry date | Jul 7, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/693
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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 biasin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.