International Business Machines Corporation

Qualcomm Incorporated

Joseph Natonio

Michael Anthony Sorna

Louis L Hsu

Xiaobin Yuan

James D Rockrohr

Mangal Prasad

Huihao Xu

Karl David Selander

Steven John Zier

Hayden C Cranford, Jr

Todd Morgan Rasmus

Patrick H Buffet

Daniel W Storaska

Joseph O Marsh

Gulsun Yasar

Robert A Proctor

James M Wilson

Louis Lu-Chen Hsu

Steven John Baumgartner

David R Hanson

Jeremy K Stephens

Carrie Ellen Cox

Minhan Chen

William Richard Kelly

Charles S Chiu

Edward R Pillai

Craig P Lussier

Hibourahima Camara

Paul E Dunn

William F Washburn

Siqi Fan

William D Corti

James Patrick Libous

Kevin Robert Bartholomew

Rory D Loughran

Jacob Lee Dahle

An Electro-Static Discharge (ESD) protection circuit is disclosed. In some implementations, the ESD protection circuit includes a first ESD diode, a second ESD diode, a passive equalization network and a programmable resistor network. The first ESD diode is coupled to the passive equalization network. The programmable resistor network is coupled between the passive equalization network and the second ESD diode. The programmable resistor network can be programmed to place the ESD protection circuit in one of a plurality of receiver modes based on a type of a transmitter from which the receiver is receiving signals.

T-coil enhanced ESD protection with passive equalization

A low power 1-tap decision feedback equalizer (DFE) is disclosed. The DFE can include a plurality of AC-coupling networks, each having an input coupled to an output of a continuous time linear equalizer (CTLE) within an active stage of a receiver to receive a corresponding pair of differential signals of data, and an output coupled to a respective one of a plurality of data samplers to present a high frequency component of the corresponding pair of differential signals to the respective data sampler. The DFE can further include a plurality of transport paths, each transport path coupled to a respective AC-coupling network to receive the corresponding pair of differential signals. Each transport path can include one of the data sampler and an injection element to passively inject an offset into the high frequency component at an input of the respective data sampler.

Low power passive offset injection for 1-tap decision feedback equalizer

One aspect of the present disclosure relates to a method for operating an amplifier, the amplifier including a variable resistor coupled between a source of a first input transistor and a source of a second input transistors, and a variable capacitor coupled between the source of the first input transistor and the source of the second input transistor. The method includes adjusting a resistance of the variable resistor to adjust a low-frequency gain of the amplifier, and adjusting a capacitance of the variable capacitor in an opposite direction as the adjustment to the resistance of the variable resistor.

Variable gain amplifier with coupled degeneration resistance and capacitance

In one implementation, an amplifier comprises a load circuit comprising a plurality of inductor cells, and a drive circuit configured to receive an input signal, and to drive the load circuit based on the input signal to generate an amplified signal. The amplifier also comprises a controller configured to tune a peaking gain of the amplifier by adjusting a number of the inductor cells that are enabled.

Amplifier with boosted peaking

A voltage gain amplifier (VGA) configured to have reduced supply noise. The VGA includes first resistor, first FET, and a first current-source coupled between first and second voltage rails. The VGA includes second resistor, second FET, and second current-source coupled between the voltage rails. A variable resistor is coupled between the respective sources of the first and second FETs. Variable capacitors are coupled between the first or a third voltage rail and the sources of the first and second input FETs, respectively. If capacitors are coupled to the first voltage rail, noise cancellation occurs across the gate-to-source voltages of the FETs if an input differential signal applied to the gates of the FETs is derived from a supply voltage at the first voltage rail. If capacitors are coupled to the third rail, supply noise is reduced if the supply voltage at the third rail is generated by a cleaner regulator.

Variable gain amplifier with improved power supply noise rejection

The disclosure relates to a system and method for controlling a common mode voltage of an output differential signal of a differential signal processing circuit using a replica circuit and feedback control. The differential signal processing circuit includes two load devices, two input transistors, and two current-source transistors coupled in series between voltage rails, respectively. The replica circuit includes replica load device, replica input transistor, and replica current-source transistor coupled in series between the voltage rails. The common mode voltage of the input differential signal is applied to the replica input transistor to generate a replica output common mode voltage. A feedback circuit generates a bias voltage for the replica current-source transistor and the current-source transistors of the differential circuit to set and control the replica output common mode voltage and the output common mode voltage of the differential signal processing circuit to a target common mode voltage.

System and method for controlling common mode voltage via replica circuit and feedback control

A system and method for testing digital to analog converters (DAC) in a serial interface having a comparator to receive an input signal and a local offset signal is disclosed. A first DAC selectably provides one of a global offset to the input signal during a normal mode of operation and a first test signal to the comparator during a test mode of operation. A second DAC selectably provides one of the local offset signals to the comparator during the normal mode of operation and a second test signal to the comparator during the test mode of operation. A test module may cause the first DAC to determine a first test signal to provide to the local offset input of the comparator and may cause the second DAC to incrementally change a test signal provided to the comparator.

Testing of digital to analog converters in serial interfaces

A design structure embodied in a machine-readable medium used in a design process provides a transmitter having a frequency response controllable in accordance with an operational parameter, and may include a storage operable to store operational parameters for controlling a frequency response of the transmitter under each of a plurality of corresponding operating conditions. A sensor can be used to detect an operating condition. In response to a change in the detected operating condition, a stored operational parameter corresponding to the detected operating condition can be used to control the frequency response of the transmitter.

Design structure for transmitter bandwidth optimization circuit

A method is provided for operating a transmitter integrated in a microelectronic element. In a calibration phase, a plurality of operational parameters are stored for controlling a frequency response of the transmitter under each of a plurality of corresponding operating conditions. Upon detecting an operating condition such as a temperature or power supply voltage level, the corresponding stored operational parameter is applied to the transmitter to control the frequency response.

Transmitter bandwidth optimization circuit

A design structure is provided for a microelectronic serial driver. The serial driver is operable to transmit a differential pattern signal during a burst interval and a predetermined common mode voltage level during a second interval between adjacent burst intervals, the serial driver including at least one pre-driver and a driver coupled to an output of the pre-driver for transmitting the differential communication signal. A switching circuit is operable to switch the serial driver between a first power supply voltage level for the burst interval and the predetermined common mode voltage level, wherein the predetermined common mode voltage level is independent of variations in power supply voltage conditions and temperature conditions.

Structure for out of band signaling enhancement for high speed serial driver

An integrated microelectronic serial driver is provided which is operable to transmit a differential pattern signal during a burst interval and a predetermined common mode voltage level during a second interval between adjacent burst intervals, the serial driver including at least one pre-driver and a driver coupled to an output of the pre-driver for transmitting the differential communication signal. A switching circuit is operable to switch the serial driver between a first power supply voltage level for the burst interval and the predetermined common mode voltage level, wherein the predetermined common mode voltage level is independent of variations in power supply voltage conditions and temperature conditions.

Out of band signaling enhancement for high speed serial driver

A method of testing connectivity through a plurality of dual purpose current mode logic ('CML') latch circuits connected in a series is provided. Each of the CML latch circuits are operable to latch at least one output signal at a timing in accordance with at least one clock signal and having a mode control device for operating the CML latch circuit as a buffer amplifier when the at least one clock signal is inactive. The method comprises the steps of activating the mode control devices of each of the CML latches to operate each of the CML latches as a buffer; inputting a first signal to a first CML latch of the series; latching an output signal of a second CML latch of the series, the second CML latch being connected at a point in the series downstream from the first CML latch; and determining whether the output signal changes in accordance with a change in the first signal.

Method of testing connectivity using dual operational mode CML latch

A signal detector and method to detect the presence or absence of an incoming differential signal. The method nullifies the DC off-set of the signal detector so that it can detect a signal within a very narrow window. The common mode levels of the signal and reference paths are used for calibration which is done automatically by use of an embedded algorithm residing in a digital block. The calibration range and resolution are predetermined to cope with the technology, modeling, design methodology and human error.

Signal detector with calibration circuit arrangement

A universal leakage monitoring system (ULMS) to measure a plurality of leakage macros during the development of a manufacturing process or a normal operation period. The ULMS characterizes the leakage of both n-type and p-type CMOS devices on the gate dielectric leakage, the sub-threshold leakage, and the reverse biased junction leakage, and the like. Testing is performed sequentially from the first test macro up to the last test macro using an on-chip algorithm. When the last test macro is tested, it scans the leakage data out.

Monitoring system for detecting and characterizing classes of leakage in CMOS devices

A dual purpose current mode logic ('CML') latch circuit is provided which includes a CML latch operable to receive at least a pair of differential input data signals and at least one clock signal. The CML latch is operable to generate at least one output signal in accordance with the states of the pair of input differential data signals. A mode control device is operable to receive a mode control signal to operate the CML latch as a buffer or as a latch. In such way, when the mode control signal is inactive, the CML latch generates and latches the output signal at a timing determined by the at least one clock signal, and when the mode control signal is active the CML latch generates the output signal such that the output signal changes whenever the states of the pair of differential input data signals change.

Growing community of inventors

Wappingers Falls, NY, United States of America

Joseph Natonio