International Business Machines Corporation

Zeynep Toprak-Deniz

John Francis Bulzacchelli

Daniel Joseph Friedman

Jonathan E Proesel

Timothy O Dickson

Martin Cochet

Alexander V Rylyakov

Joseph Andrew Iadanza

Marcel A Kossel

Michael Sperling

Todd Morgan Rasmus

Herschel Akiba Ainspan

Sergey Vladimirovich Rylov

Mounir Meghelli

Paul David Muench

Carrie Ellen Cox

Shahrzad Naraghi

An apparatus comprises one or more A-type resistance segments, wherein each A-type resistance segment comprises one or more A-type switches, at least one A-type linear resistor coupled to the one or more A-type switches, at least one A-type tunable header unit coupled to the one or more A-type switches, and at least one A-type tunable footer unit coupled to the one or more A-type switches; one or more B-type resistance segments, wherein each B-type resistance segment comprises one or more B-type switches, at least one B-type linear resistor coupled to at least a proper subset of the one or more B-type switches, at least one B-type tunable header unit coupled to the one or more B-type switches, and at least one B-type tunable footer unit coupled to the one or more B-type switches; and wherein second terminals of the A-type linear resistors and the B-type linear resistors are coupled together.

Segmented digital-to-analog converter wireline driver

A circuit includes at least three equally weighted drivers; a state variable generator; and an element selector. The latter is coupled to the drivers, has a first input from the generator, has a second input including a plurality of input thermometer-encoded data streams, and has an output of an equal number of thermometer-encoded output data streams supplied to the drivers. The element selector maps the second input to the output dynamically based on a value of the first input from the state variable generator, with an update rate that is no more than one half of a symbol-rate. A serializer is configured to provide serialized data at the symbol rate, with output coupled to one of the second input of the element selector and input of the drivers. The drivers have outputs that are combined to produce an output of the circuit at the symbol rate.

Transmitter with uniform driver segment activity

A transmitter (TX)-side feedforward equalizer (FFE) includes one or more 'roaming' filter taps which can be used to compensate reflections that occur at unpredictable and substantial time offsets from a main pulse. The roaming filter taps are realized in a hardware- and power-efficient manner by implementing a programmable delay serializer in which the phases of multi-rate clocks are switched to introduce binary weighted delays on the roaming tap. In this way a variable difference in latencies is introduced between the main and the roaming tap data paths. The TX-side FFE implementations provide a fully programmable roaming tap generator having a 1-Unit Interval (UI) resolution of delay setting integrated into the data serializer of the TX macro.

Feedforward equalizer with programmable roaming taps

Methods and systems of performing feed forward equalization (FFE) on data streams are described. A circuitry may generate staggered data streams from data streams of an input signal. The staggered data streams may include data in staggered unit intervals. The circuitry may include a plurality of segments. A segment may define a specific unit interval to carve the staggered data streams into one unit interval pulses positioned at the specific unit interval. The specific unit interval to carve the staggered data streams may indicate an assignment of the segment as one of a FFE pre tap, a FFE main tap, and a FFE post tap. The plurality of segments may be assigned to different FFE taps based on different clock signal selection defining different unit intervals to perform the carving. The plurality of segments may output respective one unit interval pulses to reproduce the input signal.

Transmitter with fully re-assignable segments for reconfigurable FFE taps

Dual-loop voltage regulator circuits and methods in which a dual-loop voltage regulation framework is implemented with a first inner loop having a bang-bang voltage regulator to achieve nearly instantaneous response time, and a second outer loop, which is slower in operating speed than the first inner loop, to controllably adjust a trip point of the bang-bang voltage regulator to achieve high DC accuracy.

Dual-loop voltage regulator architecture with high DC accuracy and fast response time

A voltage regulator includes a regulator input connected to a reference voltage; a regulator output that outputs a regulated voltage to an electrical load; a first loop, the first loop configured to receive the reference voltage, the first loop outputting a bias voltage; a second loop, the second loop configured to receive the bias voltage as an input; and a bias voltage capacitor connected to a node between the first loop and the second loop.

Dual loop voltage regulator with bias voltage capacitor

Apparatus and methods are provided relating to time-to-digital based analog-to-digital converter. An apparatus includes a time-to-digital converter based analog-to-digital converter for generating a first signal and a second signal having a timing relationship between a rising edge of the first signal and a rising edge of the second signal based on a sampled input analog voltage level, and converting the timing relationship into a corresponding time-to-digital representation. The time-to-digital representation is obtained without any voltage comparison and current comparison.

Growing community of inventors

Norwalk, CT, United States of America

Zeynep Toprak-Deniz