Abstract: Examples described herein relate to a method and a system for removing the common-mode current. The receiver includes a photodetector, a common-mode adjustment circuit, an analog front-end, an eye scan circuit, and a control unit. The photodetector generates an input photocurrent responsive to a received optical signal. The common-mode adjustment circuit generates an adjusted input current based on the input photocurrent. The analog front-end generates a differential voltage based on the adjusted input current. Based on the differential voltage, the eye scan circuit generates an eye scan information defining a first outer eye and a second outer eye in an eye diagram. The control unit tunes the common-mode adjustment circuit based on a relative height metric of a first height of the first outer eye and a second height of the second outer eye to remove a portion of the common-mode current from the input photocurrent.

Abstract: An optical or an optoelectronic device and methods are provided for data transmission across two interconnects. First, an electrical signal is obtained from an interconnect. Next, the electrical signal is modulated. Within the modulated electrical signal, an occurrence of a transition is determined, in which a change in a power of the electrical signal by more than a threshold amount. In response to the determination of the occurrence of the transition, coefficients indicative of respective amounts of compensation to resolve or mitigate nonlinearities associated with the transition are determined. According to the coefficients, a filter is applied in a vicinity of the transition to obtain a modified electrical signal. The modified electrical signal is converted into an optical signal and coupled to a fiber to transmit the optical signal to a destination at a second interconnect.

Abstract: An optical emitter includes a vertical cavity surface emitting laser (VCSEL), an equalization circuit coupled to the VCSEL; and a current source coupled to the VCSEL and the equalization circuit. The equalization circuit is configured to divert a first current from the current source to the VCSEL at a first data frequency and divert a second current greater than the first current from the current source to the VCSEL at a second data frequency higher than the first data frequency.

Abstract: An optical or an optoelectronic device and methods are provided for data transmission across two interconnects. First, an electrical signal is obtained from an interconnect. Next, the electrical signal is modulated. Within the modulated electrical signal, an occurrence of a transition is determined, in which a change in a power of the electrical signal by more than a threshold amount. In response to the determination of the occurrence of the transition, coefficients indicative of respective amounts of compensation to resolve or mitigate nonlinearities associated with the transition are determined. According to the coefficients, a filter is applied in a vicinity of the transition to obtain a modified electrical signal. The modified electrical signal is converted into an optical signal and coupled to a fiber to transmit the optical signal to a destination at a second interconnect.

Abstract: One embodiment can provide a sampler for a decision feedback equalizer (DFE). The sampler can include a comparator comprising a resolver and a plurality of amplifiers coupled to the resolver. The plurality of amplifiers are to receive an input signal and one or more feedback signals, and the plurality of amplifiers are coupled to each other in parallel, thereby facilitating a summation of the input signal and the one or more feedback signals. The comparator is to generate an output based on the summation of the input signals and the one or more feedback signals. The sampler can further include an inverter to invert the output of the comparator. The inverted output of the inverter is sent to a tap-1 amplifier to generate a tap-1 feedback signal to be sent to the comparator at a next unit interval (UI).

Abstract: A push-pull circuit for an opto-electronic device includes: an output node; a pull-up circuit that, in operation, controls a falling edge rate of an input signal to the opto-electronic device while sharing charge with the output node; and a pull-down circuit that, in operation, controls a rising edge rate of the input signal to the opto-electronic device while sharing charge with the output node.

Abstract: A pluggable module is provided for converting an optical signal to a plurality of electrical signals. The pluggable module may include a printable circuit board (PCB) and an optical connector disposed on a first side of the PCB. The optical connector may route any received optical signal to an optical to electrical transceiver. The optical to electrical transceiver may convert the optical signal to an electrical signal and route the electrical signal to an electrical connector mounted on a second, opposite side of the PCB.

Abstract: A push-pull circuit for an opto-electronic device includes: an output node; a pull-up circuit that, in operation, controls a falling edge rate of an input signal to the opto-electronic device while sharing charge with the output node; and a pull-down circuit that, in operation, controls a rising edge rate of the input signal to the opto-electronic device while sharing charge with the output node.

Abstract: The present disclosure provides an effective solution to employ hyperscale photonics connectivity using existing server connections. The solution described in the present disclosure eliminates top-of-rack switches and facilitates a manner for servers to connect directly to middle-of-row switches. An apparatus consistent with the present disclosure includes a primary transceiver device. The primary server-end transceiver device comprising a photonics transceiver and a first electrical transmitter. The apparatus further includes a first secondary server-end transceiver device, the first secondary server-end transceiver device comprising a second electrical transmitter. In addition, a first electrical cable electrically couples the primary server-end transceiver to the first secondary server-end transceiver device. The present disclosure enables the use of an input fiber connection and a photonics transceiver to effect two sets of electrical connections on different servers.

Abstract: A pluggable module is provided for converting an optical signal to a plurality of electrical signals. The pluggable module may include a printable circuit board (PCB) and an optical connector disposed on a first side of the PCB. The optical connector may route any received optical signal to an optical to electrical transceiver. The optical to electrical transceiver may convert the optical signal to an electrical signal and route the electrical signal to an electrical connector mounted on a second, opposite side of the PCB.

Abstract: The present disclosure provides an effective solution to employ hyperscale photonics connectivity using existing server connections. The solution described in the present disclosure eliminates top-of-rack switches and facilitates a manner for servers to connect directly to middle-of-row switches. An apparatus consistent with the present disclosure includes a primary transceiver device. The primary server-end transceiver device comprising a photonics transceiver and a first electrical transmitter. The apparatus further includes a first secondary server-end transceiver device, the first secondary server-end transceiver device comprising a second electrical transmitter. In addition, a first electrical cable electrically couples the primary server-end transceiver to the first secondary server-end transceiver device. The present disclosure enables the use of an input fiber connection and a photonics transceiver to effect two sets of electrical connections on different servers.

Abstract: A device, including a first current supply configured to provide a bias current to a load and a main current supply having a source terminal coupled in parallel with the load and configured to reduce a current value to the load below the bias current, is provided. The device includes a termination resistor coupled in series with the source terminal of the main current supply and configured to receive current from the source terminal of the main current supply when the source terminal of the main current supply is activated. The device also includes an auxiliary current supply having a sink terminal coupled to the termination resistor at a common node, and configured to maintain the common node at common mode voltage when current flows from the source terminal of the main current supply to the sink terminal of the auxiliary current supply and through the termination resistor.

Abstract: A server-to-switch interconnection system that includes a plurality of server modules each having wired server network connection ports, the plurality of server modules being positioned in a server rack. The switch system also includes a rack-level server photonic module that has a plurality of wired network connection ports connecting to a plurality of servers from a single photonic module, an optical transceiver in communication with the wired network connection ports, and an optical port in communication with the optical transceiver.

Abstract: A device, including a switch configured to couple a current source with an output terminal upon receipt of a data signal, is provided. The device also includes a first variable capacitor coupled in parallel to the current source at a common node on a source terminal of the switch, wherein the first variable capacitor comprises multiple capacitive elements coupled in parallel and configured to be activated by a programmable signal, and wherein the programmable signal is selected to increase a charge transfer rate from an output terminal coupled to a load, when the switch is turned on. A system and a serial interface including the above device are also provided.

Abstract: A device, including a first current supply configured to provide a bias current to a load and a main current supply having a source terminal coupled in parallel with the load and configured to reduce a current value to the load below the bias current, is provided. The device includes a termination resistor coupled in series with the source terminal of the main current supply and configured to receive current from the source terminal of the main current supply when the source terminal of the main current supply is activated. The device also includes an auxiliary current supply having a sink terminal coupled to the termination resistor at a common node, and configured to maintain the common node at common mode voltage when current flows from the source terminal of the main current supply to the sink terminal of the auxiliary current supply and through the termination resistor.

Abstract: A device, including a switch configured to couple a current source with an output terminal upon receipt of a data signal, is provided. The device also includes a first variable capacitor coupled in parallel to the current source at a common node on a source terminal of the switch, wherein the first variable capacitor comprises multiple capacitive elements coupled in parallel and configured to be activated by a programmable signal, and wherein the programmable signal is selected to increase a charge transfer rate from an output terminal coupled to a load, when the switch is turned on. A system and a serial interface including the above device are also provided.

Abstract: A technique includes determining a first phase delay associated with communication of a bit pattern having a first bit transition frequency over a communication channel; and determining a second phase delay associated with communication of a bit pattern having a second bit transition frequency greater than the first bit transition frequency over the communication channel. The technique includes regulating a compensation applied to a signal received from the communication channel based at least in part on a difference of the first and second phase delays.

Abstract: A comparator includes a resolver controlled by a resolver clock signal and a differential amplifier controlled by a sampling clock signal. The resolver clock signal and the sampling clock signal are such that amplification at the differential amplifier during the reset phase of the resolver clock signal and the reset phase of the sampling clock signal begins during the resolving phase of the resolver.

Abstract: A comparator includes a resolver controlled by a resolver clock signal and a differential amplifier controlled by a sampling clock signal. The resolver clock signal and the sampling clock signal are such that amplification at the differential amplifier during the reset phase of the resolver clock signal and the reset phase of the sampling clock signal begins during the resolving phase of the resolver.

Abstract: An example driver circuit includes a termination voltage circuit and a termination element coupled to the termination voltage circuit. The driver circuit also includes a current source switch coupled the termination element via a node. The driver circuit further includes a current source coupled to the current source switch. The current source switch and the termination voltage circuit are controlled via a control signal. The termination voltage circuit is to generate a termination voltage to match a node voltage of the node based on the control signal. The driver circuit further includes a load coupled to the termination element and the current source switch via the node. The driver circuit further includes a load voltage source coupled to the load. The node voltage is generated based on the load and the load voltage source.