Avago Technologies General IP (singapore) Pte. Ltd.

Avago Technologies International Sales Pte. Limited

Quellan, Inc.

Faouzi Chaahoub

Georgios Asmanis

Samir Aboulhouda

Michael Allen Robinson

Chakravartula Nallani

Rahul Shringarpure

Ajay Kumar Yadav

Dezhao Bai

Sriramkumar Sundararaman

Ravi Teja Kotamraju

Kartikeya Gupta

Kishan Venkataramu

Laurence Ray McColloch

David W Dolfi

Vishal Giridharan

Tony Shuo-Chun Kao

Ahmed Rashid Syed

Kazi Asaduzzaman

Alfred Sargezisardrud

Behrooz Nakhkoob

A light source driver circuit is provided that has at least first and second current source circuits that are electrically coupled to a node of the driver circuit. The first and second current source circuits source first and second fractions, respectively, of a total current needed to drive a light source into a node of the driver circuit. The driver circuit uses a sum of the first and second fractions of the total current in combination with a modulation current to drive the light source. By incorporating at least first and second current source circuits into the driver circuit, each of the current sources can be kept sufficiently small in size that they contribute very little parasitic capacitance, and therefore allow the driver circuit to achieve high-bandwidth operations while also allowing the driver circuit to operate at a low supply voltage.

Light source driver circuit that uses a low supply voltage and is capable of operating at a high bandwidth

A TIA circuit is provided that utilizes current steering to adjust the gain of a TIA of the TIA circuit. As the optical input power of the optoelectronic (OE) detector that is coupled to the input of the TIA increases, the gain of the TIA is decreased via current steering, and as the optical input power of the OE detector decreases, the gain of the TIA is increased via current steering. Utilizing current steering to adjust the gain of the TIA allows the TIA circuit to have a configuration that has reduced power consumption compared to TIA circuits that use shunt feedback TIAs. In addition the TIA circuit configuration provides reduced peaking, improved linearization and high bandwidth.

Transimpedance amplifier (TIA) circuit having reduced power consumption, improved linearization and reduced peaking

A CDR circuit for use in an optical receiver is provided that performs automatic rate negotiation. The CDR circuit is configured to determine whether the incoming data signal has a first, second or third data rate. If the CDR circuit determines that the incoming data signal has the first data rate, the CDR circuit places itself in a bypass mode of operations so that CDR is not performed. If the CDR circuit determines that the incoming data signal has the second or third data rates, the CDR circuit places itself in a CDR mode of operations and performs CDR on the incoming data signal.

Clock-and-data recovery (CDR) circuitry for performing automatic rate negotiation

A control device that may be implemented in a single IC chip is provided that is capable of controlling EAM bias voltages and DFB bias currents and of monitoring the EAM photocurrents and received signal strength indicators (RSSIs) in a multi-channel optical transceiver module. The control device IC chip can be manufactured at relatively low cost with relatively high yield, and can be implemented in a relatively small area. To implement the control device in a single IC chip, multiple supply voltage domains are used in the IC chip, one of which is a negative supply voltage domain and one of which is a positive supply voltage domain. In order to provide these different supply voltage domains, a level shift circuit is employed in the IC chip that converts signals from the positive to the negative supply voltage domain, and vice versa, and changes the voltage levels, as needed.

Control device and method for controlling biasing of multiple light sources of multiple channels of a multi-channel optical communications module

A burst-mode TIA circuit for use in PON receivers is provided that supports multiple data rates, has high receiver sensitivity, wide dynamic range, and that performs burst-mode synchronization very quickly. The multi-rate burst-mode TIA circuit has a high-speed data path that has low input-referred noise. Based on the chosen data rate at which the multi-rate burst-mode TIA circuit will operate, the rate select switch selects an appropriate feedback resistor of the resistive feedback network.

Multi-data rate, burst-mode transimpedance amplifier (TIA) circuit

An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a single-to-differential variable gain amplifier having a variable resistor switch that substantially always operates in a triode region at all time. Said another way, the resistor switch is configured to operate in a triode region regardless of whether or not a first portion of an input signal to the variable gain amplifier is larger than a second portion of the input signal. The disclosed scheme helps to keep the variable resistor switch in the triode region in all cases of operation, thereby maintaining the linearity condition and reducing distortion in the variable gain amplifier.

Low distortion single-to-differential wide-band variable gain amplifier for optical communications

An amplifier, a circuit, and an optical communication system are provided. The disclosed amplifier may include a first transistor receiving a first portion of an input signal received at the amplifier, a second transistor receiving a second portion of the input signal, an automatic gain control signal that is dynamically adjustable in response to variations in an output of the amplifier, and a varactor that has its capacitance adjusted by changes in the automatic gain control signal and, as a result, adjusts a position of a pole in a transfer function of the amplifier.

Linearizing and reducing peaking simultaneously in single-to-differential wideband radio frequency variable gain trans-impedance amplifier (TIA) for optical communication

A digitally-controlled transimpedance amplifier (TIA) circuit is provided in which a plurality of feedback loops are digitally controlled, including, but not limited to, the DC offset cancellation loop, the variable gain control loop, and the TIA feedback impedance adjustment loop. The digitally-controlled TIA circuit includes digital loop-control circuitry that consumes less area on the TIA IC chip than the analog circuitry traditionally used to perform the feedback loop control in the analog domain. In addition, because digital logic continues to shrink as IC processes continue to evolve, the size of the IC chip packages will further decrease over time, leading to a smaller footprint in systems in which they are employed. The digital loop control circuitry is also capable of independently varying the gains of multiple gain stages of the variable gain control circuit to provide better control over the gain stages and better overall performance of the TIA circuit.

Digitally-controlled transimpedance amplifier (TIA) circuit and methods

Each channel of a high speed multi-channel transmitter or receiver IC chip layout is partitioned into at least first and second channel portions that are electrically interconnected with one another. Each first channel portion has an end that is located on an optical interface side of the multi-channel transmitter or receiver IC chip. Each second channel portion has an end that is located on an electrical interface side of the multi-channel transmitter or receiver IC chip. The pitch between the first channel portions is very fine and matches the pitch between optoelectronic elements of an optoelectronic array chip that interfaces with the optical interface side of the multi-channel transmitter or receiver IC chip. The pitch between the second channel portions is significantly greater than the pitch between the first channel portions to prevent cross talk.

Multi-channel optical communications integrated circuit chip having an improved layout for use in multi-channel optical transmitters, receivers and transceivers

An optical communication system, circuit, and Integrated Circuit (IC) chip are disclosed. The disclosed optical communication system includes a photodiode configured to receive light energy and convert the light energy into an electrical signal, an amplifier configured to receive the electrical signal from the photodiode and output an amplified electrical signal, and a control circuit comprising a biasing network that generates a modular logic level that scales with a bias voltage of the photodiode.

Supply voltage modular photodiode bias

An optical communication system, a linear optical receiver, and an Integrated Circuit (IC) chip are disclosed, among other things. One example of the disclosed IC chip includes a transimpedance amplifier that receives an input electrical signal from a photodiode and provides an amplified version of the input electrical signal as an output, at least one variable gain amplifier that receives the amplified electrical signal output by the transimpedance amplifier and a bandwidth control mechanism that extends a bandwidth of the second amplified output at a maximum gain of the second amplification phase and also reduces a peaking of the second amplified output at a minimum gain of the second amplification phase.

Simultaneous bandwidth extension at high gain and peaking reduction at minimum gain for wideband, variable gain, linear optical receivers

A low-power, direct-drive EML driver circuit is provided that reduces power consumption by reducing the amount of current needed to create the necessary voltage swing in the drive signal. In addition, the EML driver circuit has an impedance matching network that has reduced complexity and that can be made at reduced costs compared to the impedance matching network of a typical EML driver circuit.

Low-power, direct-drive driver circuit for driving an externally modulated laser (EML), and methods

An optical communication system, a circuit, and a method of operating an optical communication system are provided. The optical communication system is disclosed to include a photodiode configured to receive optical signals and convert the received optical signals into electrical signals, a Trans-Impedance Amplifier (TIA) electrically connected with the photodiode such that the TIA receives the electrical signals from the photodiode and is configured to convert the electrical signals received from the photodiode into amplified electrical signals, and a feedback loop connected between an input of the TIA and an output of the TIA that includes a switchable capacitor bank connected thereto which introduces at least one zero into a feedback factor transfer function of the TIA thereby tuning out poles or equalizing delay introduced by a TIA input network connected between the photodiode and the input of the TIA.

Equalization scheme in trans-impedance amplifier for optical communications

A current mirror circuit is provided that has a feedback loop that includes a current mirror that provides base current compensation to the bases of the input and output transistors of the current mirror circuit. By employing a current mirror in the feedback loop to provide base current compensation, the minimum power supply voltage of the current mirror circuit is very low, typically less than or equal to about 1.5 V.

Low-voltage current mirror circuit and method

A transmitter is disclosed as being configured to encode optical signals in accordance with a multi-level coding scheme. The transmitter includes an Integrated Circuit architecture and partition that relaxes the bandwidth and linearity constraints of a gearbox-to-laser driver interface. In the proposed architecture, the gearbox Integrated Circuit aligns two or more digital data streams and transmits the aligned two or more data streams to the laser driver via separate signals.

Growing community of inventors

San Jose, CA, United States of America

Faouzi Chaahoub