公开(公告)号：US09735989B1

公开(公告)日：2017-08-15

申请号：US15190575

申请日：2016-06-23

Applicant: Oracle International Corporation

Inventor： Jingqiong Xie ,  Ashok V. Krishnamoorthy ,  Xuezhe Zheng ,  Jeffrey W. Denq ,  Kannan Raj

IPC: H04L25/03 ,  H04L27/01 ,  H04B3/14 ,  H03F3/45 ,  H04L25/08 ,  H04L25/02 ,  H04B1/12

CPC classification number: H04L25/03885 ,  H03F1/3211 ,  H03F3/45188 ,  H03F3/45201 ,  H03F2203/45318 ,  H03F2203/45638 ,  H03F2203/45702 ,  H04B1/123 ,  H04B3/14 ,  H04L25/0272 ,  H04L25/03012 ,  H04L25/03878 ,  H04L25/085 ,  H04L27/01

Abstract: The disclosed embodiments relate to the design of an equalizer that uses both cross-coupled cascodes and inductive peaking to reduce distortion in a signal received from a communication channel by attenuating lower frequencies and amplifying higher frequencies. At lower frequencies, when the effects of inductive impedance within the equalizer are negligible, the equalizer essentially functions as a traditional cascode amplifier that presents high gain. At higher frequencies, the increases in inductive impedances within the equalizer act to boost a gain of the equalizer.

公开(公告)号：US09819421B1

公开(公告)日：2017-11-14

申请号：US15204372

申请日：2016-07-07

Applicant: Oracle International Corporation

Inventor： Jingqiong Xie ,  Ashok V. Krishnamoorthy ,  Xuezhe Zheng ,  Jeffrey W. Denq ,  Kannan Raj ,  John E. Cunningham ,  Hiren D. Thacker

IPC: H04B10/69

CPC classification number: H04B10/693

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.