A system for limiting or diminishing current to unpowered Serializer/Deserializer (SerDes) circuitry is provided. The system comprises receiver input termination circuitry and a cold spare circuitry. The receiver input circuitry comprises a termination resistor and an N-type metal oxide silicon field effect transistor (MOSFET). The cold spare circuitry comprises a first MOSFET and a second MOSFET. When the system is powered on, an input current flows to the receiver input termination circuit to be discharged by the N-type MOSFET which is electrically connected to a ground. When the system is powered off, the input current flows to the cold spare circuitry to discharge the input current. Discharging electrons between the first MOSFET and the second MOSFET depends on the polarity of an accumulated voltage.

A true single-phase clocked multiplexer for outputting one of a plurality of input signals in synchronization with a clock signal and as selected by at least one select signal is provided. The multiplexer includes first transistors, second transistors, a first node between the first transistors, a second node between the second transistors, a third node coupled to the first node by one of the first transistors and to the second node by one of the second transistors, and a pre-charge transistor to couple the third node to a first voltage level. The first transistors are coupled to the first voltage level and configured to turn on in response to a gate voltage of a second voltage level different from the first voltage level. The second transistors are coupled to the second voltage level and configured to turn on in response to a gate voltage of the first voltage level.

An ultra-low latency communication device includes a clock recovery module, a de-serializer module, an FPGA fabric and a serializer module. The clock recovery module receives an incoming electrical physical layer serial signal and recovers a recovered clock signal therefrom. The de-serializer module converts the incoming electrical physical layer serial signal to an incoming electrical physical layer parallel signal according to driving signals generated based on the recovered clock signal. The FPGA fabric processes the incoming electrical physical layer parallel signal to output an incoming data-link layer parallel signal, receives an outgoing data-link layer parallel signal generated based on electronic information contained in the incoming data-link layer parallel signal, and processes the outgoing data-link layer parallel signal to output an outgoing electrical physical layer parallel signal. The serializer module converts the outgoing electrical physical layer parallel signal to an outgoing electrical physical layer serial signal.

A true single-phase clocked multiplexer for outputting one of a plurality of input signals in synchronization with a clock signal and as selected by at least one select signal is provided. The multiplexer includes first transistors, second transistors, a first node between the first transistors, a second node between the second transistors, a third node coupled to the first node by one of the first transistors and to the second node by one of the second transistors, and a pre-charge transistor to couple the third node to a first voltage level. The first transistors are coupled to the first voltage level and configured to turn on in response to a gate voltage of a second voltage level different from the first voltage level. The second transistors are coupled to the second voltage level and configured to turn on in response to a gate voltage of the first voltage level.

A system for serializing input data signals and generating an output data signal includes a FIFO memory that launches the input data signals at different phases of a clock signal. The system further includes multiple stages of a serializer circuit, and each stage of the serializer circuit receives a clock signal. Each successive stage includes half the number of serializer circuits that are included in the previous stage, and each successive stage is clocked by a clock signal that transitions at twice the frequency of the previous stage clock signal. The serializer circuits that belong to a single stage receive the clock signal with different phase. The phase and frequency of clock signals of serializer stages are adjusted such that a launched input data signal is outputted as the output data signal. Further, a critical path for each serializer circuit is equal to full clock cycle of the clock signal.

A serializer circuit may include a recovery circuit, an adjusting circuit, and a multiplexer circuit. The recovery circuit may be configured to receive a first data signal at a first frequency, to generate a first clock signal at the first frequency using the first data signal, and to retime the first data signal based on the first clock signal to generate a retimed first data signal. The adjusting circuit may be configured to receive a second data signal and retime the second data signal based on the first clock signal to generate a retimed second data signal. The multiplexer circuit may be configured to multiplex the retimed first data signal and the retimed second data signal.

An optical transceiver configured to operate in a host device includes an electrical interface communicatively coupled to the host device to interface electrically with the host device, wherein the optical transceiver is compliant with a Multi-Source Agreement (MSA) which is supported by the host device; optical transceiver components communicatively coupled to the electrical interface, wherein the optical transceiver components are configured to optically interface signals with a second optical transceiver to form an optical link; and electronic dispersion compensation circuitry communicatively coupled to the optical transceiver components and configured to electronically compensate for optical fiber chromatic and/or polarization mode dispersion associated with the optical link, separate and independent from the host device.

A multiplexer comprises: an output circuit comprising a multiplexer output; and a first buffer coupled to the output circuit and comprising: a first selection input configured to receive a first selection signal; a first logical input configured to receive a first logical input signal; and a first ground; wherein the multiplexer is configured to: couple the first logical input to the multiplexer output when the first selection signal is a first value; and couple the first logical input to the first ground when the first selection signal is a second value. A method comprises: receiving a selection signal and a first logical input signal; coupling a first logical input to a multiplexer output when the selection signal is a first value; and coupling the first logical input to a ground when the selection signal is a second value.

Techniques efficiently serialize multiple data streams using quadrature clocks. Serializer employs first, second, third, and fourth clock signals. Serializer receives multiple data streams via registers, with each of four paths comprising a register, buffer, and switch, with registers of first and fourth paths associated with third clock signal, and registers of second and third paths associated with first clock signal, and with switches of first and fourth paths associated with first clock signal, and switches of second and third paths associated with third clock signal. Switches of first and second paths transfer respective data bits to fifth switch via another buffer, wherein fifth switch is associated with a delayed second clock signal of a time delay component (TDC). Switches of third and fourth paths transfer respective data bits to sixth switch via another buffer, wherein sixth switch is associated with a delayed fourth clock signal of TDC.

Multiplexing circuitry and method for driving multiplexing circuits are provided. A circuit includes a multiplexer circuit having symmetrical data input paths driven by a half-rate clock signal and a first stage multiplexing circuit configured to provide input signals to the multiplexer circuit. The first stage multiplexing circuit is driven by quadrature clocks to generate time-shifted data.