Abstract: System for reducing pattern-dependent inter-symbol interference (ISI) are described. These systems may be implemented using complementary metal-oxide-semiconductor (CMOS) transistors. These systems are designed to clamp the voltage propagating along the datapath to a value that is a fraction of the supply voltage. Furthermore, these systems are designed to reduce the time constant of the datapath. One such system comprises a source including a digital-to-analog converter (DAC) and a destination comprising an analog-to-digital converter (ADC). A circuit disposed along the data path from the DAC to the ADC is configured to receive a supply voltage, receive an input signal from the DAC, and produce an output signal based on the input signal by clamping the output signal to a voltage that is a fraction of the supply voltage.

Abstract: Systems and methods for detecting the presence and/or location of defects (e.g., incomplete solders, broken cables, misconnections, defective sockets, opens, shorts, etc.) along electrical lines are described. The systems and methods described herein may use time-domain reflectometry (TDR), a measurement technique used to determine the characteristics of electrical lines by observing reflected waveforms. TDR may be performed in some embodiments by determining the times when a first event and a second event occur, and by determining the space traveled by a probe signal based on these times. The first event may occur when a first signal transition crosses a first threshold and the second event may occur when a second signal transition crosses a second threshold, where the second signal transition may arise in response to the first signal transition reflecting against a defect along the electrical line.

Abstract: Systems and methods for detecting the presence and/or location of defects (e.g., incomplete solders, broken cables, misconnections, defective sockets, opens, shorts, etc.) along electrical lines are described. The systems and methods described herein may use time-domain reflectometry (TDR), a measurement technique used to determine the characteristics of electrical lines by observing reflected waveforms. TDR may be performed in some embodiments by determining the times when a first event and a second event occur, and by determining the space traveled by a probe signal based on these times. The first event may occur when a first signal transition crosses a first threshold and the second event may occur when a second signal transition crosses a second threshold, where the second signal transition may arise in response to the first signal transition reflecting against a defect along the electrical line.

Abstract: System for reducing pattern-dependent inter-symbol interference (ISI) are described. These systems may be implemented using complementary metal-oxide-semiconductor (CMOS) transistors. These systems are designed to clamp the voltage propagating along the datapath to a value that is a fraction of the supply voltage. Furthermore, these systems are designed to reduce the time constant of the datapath. One such system comprises a source including a digital-to-analog converter (DAC) and a destination comprising an analog-to-digital converter (ADC). A circuit disposed along the data path from the DAC to the ADC is configured to receive a supply voltage, receive an input signal from the DAC, and produce an output signal based on the input signal by clamping the output signal to a voltage that is a fraction of the supply voltage.

Abstract: An attenuator system comprising a variable impedance configured to provide an impedance from among a plurality of impedance states, the variable impedance comprising a first port, a second port, a first transistor comprising first and second channel terminals coupled between the first port and the second port, and a second transistor comprising first and second channel terminals coupled between the first port and the second port, and a control circuit configured to control the variable impedance to a first impedance state of the plurality of impedance states at least in part by providing a first output voltage to a control terminal of the first transistor to turn the first transistor on, wherein the first transistor is configured to operate in an under-driven mode when turned on.

Abstract: An attenuator system comprising a variable impedance configured to provide an impedance from among a plurality of impedance states, the variable impedance comprising a first port, a second port, a first transistor comprising first and second channel terminals coupled between the first port and the second port, and a second transistor comprising first and second channel terminals coupled between the first port and the second port, and a control circuit configured to control the variable impedance to a first impedance state of the plurality of impedance states at least in part by providing a first output voltage to a control terminal of the first transistor to turn the first transistor on, wherein the first transistor is configured to operate in an under-driven mode when turned on.

Abstract: Systems and method for supply noise suppression in electronic circuits are described. The systems described herein may prevent or at least limit noise coupling from a supply line to a load, and may further prevent or at least limit noise generated at the load from coupling to the supply line. The systems and methods described herein may be particularly useful in systems-on-chip with multi-level interposers, in which multiple supply lines are used to provide different voltage levels to the chip. In these systems, in fact, the supply lines can exhibit large impedances, which may in turn promote noise coupling from one circuit to another. In one example, a voltage regulator is provided that includes a linear regulator and an active shunt circuit.

Abstract: Systems and methods for detecting the presence and/or location of defects (e.g., incomplete solders, broken cables, misconnections, defective sockets, opens, shorts, etc.) along electrical lines are described. The systems and methods described herein may use time-domain reflectometry (TDR), a measurement technique used to determine the characteristics of electrical lines by observing reflected waveforms. TDR may be performed in some embodiments by determining the times when a first event and a second event occur, and by determining the space traveled by a probe signal based on these times. The first event may occur when a first signal transition crosses a first threshold and the second event may occur when a second signal transition crosses a second threshold, where the second signal transition may arise in response to the first signal transition reflecting against a defect along the electrical line.

Abstract: Circuits and methods for delay mismatch compensation are described. A circuit may comprise multiple data paths between a signal source, such as a driver, and a load. The paths may have different lengths, thus causing delay mismatches. An exemplary circuit of the type described herein may comprise delay elements and at least one feedback circuit designed to compensate for such delay mismatches. The circuit may operate in different phases, such as a compensation phase and a driving phase. In the compensation phase, rings oscillators including delay elements and the at least one feedback circuit may be formed. In this phase the delay may be adjusted to compensate for mismatches. In the driving phase, the signal source may be connected to the load.