Abstract: Systems and methods are related to a successive approximation analog to digital converter (SAR ADC). The SAR ADC includes a sample and digital to analog conversion (DAC) circuit configured to sample an input voltage, a comparator circuit coupled to the sample and DAC circuit and having an output, a first set of storage circuits, and a comparator driver. The comparator driver is disposed between the output and the first set of storage circuits (e.g., ratioed latched. The first set of storage circuits are coupled to the comparator circuit and the sample and DAC circuit. The comparator driver can include a first driver and second driver. The first driver is coupled to a first input of a first storage circuit of the first set of storage circuits, and the second driver is coupled to first inputs of a second set of storage circuits within the first set of storage circuits.

Abstract: Systems and methods are related to a successive approximation analog to digital converter (SAR ADC). The SAR ADC includes a sample and digital to analog conversion (DAC) circuit configured to sample an input voltage, a comparator circuit coupled to the sample and DAC circuit and having an output, a first set of storage circuits, and a comparator driver. The comparator driver is disposed between the output and the first set of storage circuits (e.g., ratioed latched. The first set of storage circuits are coupled to the comparator circuit and the sample and DAC circuit. The comparator driver can include a first driver and second driver. The first driver is coupled to a first input of a first storage circuit of the first set of storage circuits, and the second driver is coupled to first inputs of a second set of storage circuits within the first set of storage circuits.

Abstract: Systems and methods are related to a successive approximation analog to digital converter (SAR ADC). The SAR ADC includes a sample and digital to analog conversion (DAC) circuit configured to sample an input voltage, a comparator circuit coupled to the sample and DAC circuit and having an output, a first set of storage circuits, and a comparator driver. The comparator driver is disposed between the output and the first set of storage circuits (e.g., ratioed latched. The first set of storage circuits are coupled to the comparator circuit and the sample and DAC circuit. The comparator driver can include a first driver and second driver. The first driver is coupled to a first input of a first storage circuit of the first set of storage circuits, and the second driver is coupled to first inputs of a second set of storage circuits within the first set of storage circuits.

Abstract: Systems and methods are related to a successive approximation analog to digital converter (SAR ADC). In one aspect, a method includes sampling, by a sample and digital to analog conversion (DAC) circuit, an input voltage to obtain a sampled voltage. The method also includes determining, by a comparator coupled to a set of storage circuits, a state of a plurality of bits corresponding to the sampled voltage. The comparator has a current parameter or voltage parameter adjusted based upon a conversion margin. Adjustment of the current parameter or the voltage parameter affects speed of determining the state of the bits. The method also includes storing the bits in the set of storage circuits. In some aspects, an SAR ADC is configured to perform the method.

Abstract: Disclosed herein are related to a system and a method for high speed communication. In one aspect, the system includes a set of slicers configured to generate a slicer output signal digitally indicating a level of an input signal received by the set of slicers. The system includes a speculative tap coupled to the set of slicers, where the speculative tap is configured to select bits of the slicer output signal based on selected bits of a prior slicer output signal. The system includes a decoder coupled to the speculative tap, where the decoder is configured to decode the selected bits of the slicer output signal in a first digital representation into a second digital representation. The system includes a feedback generator coupled to the decoder, where the feedback generator is configured to generate a feedback signal according to the decoded bits of the slicer output signal.

Abstract: Disclosed herein are related to a system and a method for high speed communication. In one aspect, the system includes a set of slicers configured to generate a slicer output signal digitally indicating a level of an input signal received by the set of slicers. The system includes a speculative tap coupled to the set of slicers, where the speculative tap is configured to select bits of the slicer output signal based on selected bits of a prior slicer output signal. The system includes a decoder coupled to the speculative tap, where the decoder is configured to decode the selected bits of the slicer output signal in a first digital representation into a second digital representation. The system includes a feedback generator coupled to the decoder, where the feedback generator is configured to generate a feedback signal according to the decoded bits of the slicer output signal.

Abstract: Disclosed herein are related to a system and a method for high speed communication. In one aspect, the system includes a set of slicers configured to generate a slicer output signal digitally indicating a level of an input signal received by the set of slicers. The system includes a speculative tap coupled to the set of slicers, where the speculative tap is configured to select bits of the slicer output signal based on selected bits of a prior slicer output signal. The system includes a decoder coupled to the speculative tap, where the decoder is configured to decode the selected bits of the slicer output signal in a first digital representation into a second digital representation. The system includes a feedback generator coupled to the decoder, where the feedback generator is configured to generate a feedback signal according to the decoded bits of the slicer output signal.

Abstract: A keeper based switch driver can generate overlapping differential signals and increase a crossing point of the overlapping differential signals a first predetermined amount. Additionally, the keeper based switch driver can further increase the crossing point of the overlapping differential signals a second predetermined amount and limit signal swing to an absolute value of a drain-source voltage. A microprocessor can also be electrically connected to a DAC cell with keeper based switch driver through a performance detection circuit. The microprocessor can be configured to receive information from a performance detection circuit and control a current of a variable current source in a keeper bias circuit accordingly.

Abstract: A keeper based switch driver can generate overlapping differential signals and increase a crossing point of the overlapping differential signals a first predetermined amount. Additionally, the keeper based switch driver can further increase the crossing point of the overlapping differential signals a second predetermined amount and limit signal swing to an absolute value of a drain-source voltage. A microprocessor can also be electrically connected to a DAC cell with keeper based switch driver through a performance detection circuit. The microprocessor can be configured to receive information from a performance detection circuit and control a current of a variable current source in a keeper bias circuit accordingly.

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: 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 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: Embodiments of the present disclosure enable bandwidth extension of receiver front-end circuits without the use of inductors. As a result, significantly smaller and cheaper receiver implementations are made possible. In an embodiment, bandwidth extension is achieved by virtue of very small floating capacitors that are coupled around amplifier stages of the receiver front-end circuit. Each of the capacitors is configured to generate a negative capacitance for the preceding stage (e.g., equalizer or amplifier), thus extending the bandwidth of the preceding stage. A capacitively-degenerated cross-coupled transistor pair allows bandwidth extension for the final (e.g., amplifier) stage. Embodiments further enable DC offset compensation with the use of a digital feedback loop. The feedback loop can thus be turned on/off as needed, reducing power consumption.

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.

Abstract: Techniques are described herein that provide an interface for receiving and deserializing digital bit stream(s). For instance, a receiver for a high-speed deserializer may include digital slicers, a digital phase interpolator, and a digital clock phase generator. The digital slicers may be configured to determine a digital value of a data input. The digital phase interpolator may be configured to generate an interpolated clock signal based on input clock signals that correspond to respective phases of a reference clock. The phase of the interpolated clock tracks the data input to the receiver through a clock recovery loop. The digital clock phase generator may be configured to generate output clock signals to control timing of the respective digital slicers. The receiver may further include a single digital eye monitor configured to monitor a data eye of the data input.

Abstract: Embodiments provide a reference-less frequency detector that overcomes the “dead zone” problem of conventional circuits. In particular, the frequency detector is able to accurately resolve the polarity of the frequency difference between the VCO clock signal and the data signal, irrespective of the magnitude of the frequency difference and the presence of VCO clock jitter and/or ISI on the data signal.

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 phase lock loop with multiple divider paths is presented herein. The phase lock loop can be used to provide a wide range of frequencies. The phase lock loop can also be used as a portion of a clock multiplier unit or a clock data and recovery unit.