Abstract: An optical module includes an optical receiver with a complementary metal-oxide semiconductor (CMOS) transimpedance amplifier (TIA) and a digital signal processing (DSP) circuit. The DSP circuit is integrated with the CMOS TIA and facilitates adaptability of the CMOS TIA, and the CMOS TIA can adapt by using information provided by the DSP circuit.

Abstract: A system is provided that includes a first electronic device, multiple second electronic devices coupled to the first electronic device via respective interfaces, and a clock generator coupled to the second electronic devices and configured to generate and provide a clock signal to each of the second electronic devices for clocking operation of the second electronic devices. The clock signal is a gapped clock signal having at least one gap created by the clock generator removing one or more clock pulses based on a synchronization signal, and the second electronic devices are configured to synchronize data transmission between the second electronic devices and the first electronic device via the interfaces using the at least one gap in the gapped clock signal to align the data transmission.

Abstract: Disclosed herein are related to systems and methods for providing different power supply levels. In one aspect, a first circuit generates a first signal having a first amplitude according to a first supply voltage. A latch may be coupled to a resistor of a plurality of resistors coupled in series. One end of the resistor may be configured to provide to the latch a second supply voltage higher than the first supply voltage according to a third supply voltage higher than the second supply voltage, and another end of the resistor may be configured to receive the third supply voltage. The latch may modify the first signal to provide a second signal, according to the second supply voltage. An amplifier may amplify the second signal to provide a third signal having a second amplitude larger than the first amplitude, according to the third supply voltage.

Abstract: A pre-driver circuit includes a differential input circuit to receive a differential-input voltage. A latch circuit can latch voltage levels of output-voltage signals at a differential output port of the pre-driver circuit. A pair of capacitors couple the differential input circuit to the latch circuit. The pre-driver circuit can enable peaking of the output-voltage signals for high-speed operation of the pre-driver circuit and a digital-to-analog converter (DAC)-driver circuit coupled to the pre-driver circuit.

Abstract: Systems and methods disclosed herein provide a coupled T-coil circuit for differential mode bandwidth extension and common mode rejection. The coupled T-coil circuit includes a first layer including at least a first portion of a first T-coil circuit and a first portion of a second T-coil circuit, and a second layer disposed on top of the first layer and interconnected to the first layer, the second layer including at least a second portion of the first T-coil circuit and a second portion of the second T-coil circuit. The first T-coil circuit includes one or more first coils with a first wind direction. The second T-coil circuit comprises one or more second coils with a second wind direction. The first wind direction can be opposite the second wind direction.

Abstract: A communication system may include a number of communication channels operating in accordance with one or more communication standards. The channels may generate data clocks from one or more master clock signals. The phase of the data clocks may be aligned using phase detectors for determining respective phase relationships and using phase interpolators for adjusting respective clock phases. The communication system may include communication channels that operate at different data clock frequencies. These systems may divide their respective data clocks in order to achieve a common clock frequency for use in their phase alignment. The phase detectors and associated circuitry may be disabled to save power when not in use.

Abstract: An apparatus for driving a load using a low supply voltage includes a voltage-mode driver and a current source arrangement. The voltage-mode driver provides a desired termination impedance and a first portion of a desired output current to the load. The current source arrangement provides a second portion of the desired output current. The desired output current generates a predetermined voltage swing across the load, while the voltage-mode driver and the current source arrangement are powered by the low supply voltage.

Abstract: A time-interleaved digital-to-analog converter (DAC) architecture is provided. The DAC architecture includes a multiplexer/encoder configured to receive a data signal and to generate a plurality of data streams based on the data signal. First and second DAC circuits receive respective first and second data streams of the plurality of data streams and selectively process the respective first and second data streams to generate a respective DAC output signal. The respective DAC output signals of the first and second DAC circuits are coupled together to provide an output signal of the DAC architecture.

Abstract: A low-power reconfigurable voltage-mode digital-to-analog converter (DAC) driver circuit includes a first and a second supply voltage and a number of DAC units. Each DAC unit is coupled to a respective bit of a digital input. The DAC units are configured to maintain a constant output impedance. Each DAC unit includes one or more complementary switch pairs that couple first nodes of one or more respective impedances to one of the first or the second supply voltage, based on the respective bit of the digital input. Second nodes of the one or more respective impedances are coupled to an output node.

Abstract: A low-power reconfigurable voltage-mode digital-to-analog converter (DAC) driver circuit includes a first and a second supply voltage and a number of DAC units. Each DAC unit is coupled to a respective bit of a digital input. The DAC units are configured to maintain a constant output impedance. Each DAC unit includes one or more complementary switch pairs that couple first nodes of one or more respective impedances to one of the first or the second supply voltage, based on the respective bit of the digital input. Second nodes of the one or more respective impedances are coupled to an output node.

Abstract: A low-power high-swing current-mode logic (CML) driver circuit includes a first differential-pair and a second differential-pair. The first differential-pair includes first transistors, and is coupled to a first voltage supply that supplies a first voltage. The second differential-pair includes second transistors, and a common node of the second differential-pair is coupled to a second voltage supply. The second voltage supply supplies a second voltage that is higher than the first voltage. Control terminals of the first transistors are coupled to control terminals of the second transistors to form input nodes of the driver circuit.

Abstract: Methods, systems, and apparatuses are described for reducing the latency in a transceiver. A transceiver includes a high latency communication channel and a low latency communication channel that is configured to be a bypass channel for the high latency communication channel. The low latency communication channel may be utilized when implementing the transceiver is used in low latency applications. By bypassing the high latency communication channel, the high latency that is introduced therein (due to the many stages of de-serialization used to reduce the data rate for digital processing) can be avoided. An increase in data rate is realized when the low latency communication channel is used to pass data. A delay-locked loop (DLL) may be used to phase align the transmitter clock of the transceiver with the receiver clock of the transceiver to compensate for a limited tolerance of phase offset between these clocks.

Abstract: Embodiments for reference-less voltage controlled oscillator (VCO) calibration are provided. Embodiments include a VCO calibration module which uses one or more signals from a frequency detector to automatically select a proper VCO band and bring the VCO clock frequency close enough to the data rate. The VCO calibration module uses a calibration code to calibrate the VCO. In embodiments, the calibration code is determined using a frequency search scheme, which includes a discovery phase to determine the proper VCO band, and a binary search phase and a monitoring phase to select the calibration code that brings the VCO clock frequency closest to the data rate.

Abstract: A high-speed clock generator device includes a phase-interpolator (PI) circuit, a smoothing block, and inverter-based low-pass filters. The PI circuit receives a multiple clock signals with different phase angles and generates an output clock signal having a correct phase angle. The smoothing block smooths the clock signals with different phase angles and generates a number of smooth clock signals featuring improved linearity. The inverter-based low-pass filters filter harmonics of the clock signals with different phase angles.

Abstract: A programmable frequency receiver includes a slicer for receiving data at a first frequency, a de-multiplexer for de-multiplexing the data at a second frequency, a programmable clock generator for generating a clock at the first frequency, and first and second resonant clock amplifiers for amplifying clock signals at the first and second frequencies. The resonant clock amplifiers include an inductor having a low Q value, allowing them to amplify clock signals over the programmable frequency range of the receiver. The second resonant clock amplifier includes digitally tunable delay elements to delay and center the amplified clock signal of the second frequency in the data window at the interface between the slicer and the de-multiplexer. The delay elements can be capacitors. A calibration circuit adjusts capacitive elements within a master clock generator to generate a master clock at the first frequency.

Abstract: An apparatus for driving a load using a low supply voltage includes a voltage-mode driver and a current source arrangement. The voltage-mode driver provides a desired termination impedance and a first portion of a desired output current to the load. The current source arrangement provides a second portion of the desired output current. The desired output current generates a predetermined voltage swing across the load, while the voltage-mode driver and the current source arrangement are powered by the low supply voltage.

Abstract: A communication system may include a number of communication channels operating in accordance with one or more communication standards. The channels may generate data clocks from one or more master clock signals. The phase of the data clocks may be aligned using phase detectors for determining respective phase relationships and using phase interpolators for adjusting respective clock phases. The communication system may include communication channels that operate at different data clock frequencies. These systems may divide their respective data clocks in order to achieve a common clock frequency for use in their phase alignment. The phase detectors and associated circuitry may be disabled to save power when not in use.

Abstract: A communication system may include a number of communication channels operating in accordance with one or more communication standards. The channels may generate data clocks from one or more master clock signals. The phase of the data clocks may be aligned using phase detectors for determining respective phase relationships and using phase interpolators for adjusting respective clock phases. The communication system may include communication channels that operate at different data clock frequencies. These systems may divide their respective data clocks in order to achieve a common clock frequency for use in their phase alignment. The phase detectors and associated circuitry may be disabled to save power when not in use.

Abstract: Reference-less repeating circuits provide significant advantages over repeating circuits requiring external frequency references. These repeating circuits eliminate the need for external frequency references provide significant power, layout, and physical isolation advantages. Digitally controlled reference-less repeating circuits have a relatively narrow frequency detection range, but typically consume significantly less power than analog repeating circuits while providing data rate flexibility, particularly at lower data rates. Due to the narrow frequency detection range of digitally controlled reference-less repeating circuits, efficient frequency estimation techniques allow these circuits to quickly lock to an input signal, and provide an accurate repeated output signal.

Abstract: Reference-less repeating circuits provide significant advantages over repeating circuits requiring external frequency references. These repeating circuits eliminate the need for external frequency references provide significant power, layout, and physical isolation advantages. Digitally controlled reference-less repeating circuits have a relatively narrow frequency detection range, but typically consume significantly less power than analog repeating circuits while providing data rate flexibility, particularly at lower data rates. Due to the narrow frequency detection range of digitally controlled reference-less repeating circuits, efficient frequency estimation techniques allow these circuits to quickly lock to an input signal, and provide an accurate repeated output signal.