Analog Devices,inc.

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Kimo Tam

Jennifer Lloyd

Michael C St Germain

Stuart John McCracken

Pablo Acosta-Serafini

Hajime Shibata

Sharvil Pradeep Patil

Daniel J Mulcahy

Mohammad Hassan Ghaed

Wenhua William Yang

Gabriele Manganaro

Yunzhi Dong

John G Kenney

David Nelson Alldred

Stefano I D'Aquino

Jesse R Bankman

Yukihisa Handa

John Kenney

Quanli Lu

Stuart Mccracken

An example residue generation arrangement for a continuous time or hybrid ADC includes a delay circuit having a cascade of analog delay sections, each section to provide a respective delay to an analog input signal, thus providing a delayed analog input signal at the output of the delay circuit. The delay circuit further includes a selector, configured to select an input or an output of one of the delay sections to provide as an input signal to a quantizer of a feedforward path. The quantizer may generate a digital input to a DAC of the feedforward path based on the output of the selector, and the DAC may generate a feedforward path analog output based on the digital signal generated by the quantizer. The arrangement further includes a summation node, configured to generate a residue signal based on the delayed analog input and the feedforward path analog output.

Continuous-time residue generation analog-to-digital converter arrangements with programmable analog delay

Various examples are directed to systems and methods for providing correction to cascaded signal components. A correction signal may be applied to multiple signal components in a set of cascaded signal components.

Parameter correction for cascaded signal components

A residue generation apparatus for use in continuous-time and hybrid ADCs is proposed. The apparatus includes a quantizer for digitizing an analog input to generate a digital output, and means for applying a first transfer function to the digital output from the quantizer to generate a digital input to a feedforward DAC, based on which the DAC can generate a feedforward path analog output. The apparatus further includes means for applying a second, continuous-time, transfer function to the analog input provided to the quantizer to generate a forward path analog output, and a subtractor for generating a residue signal based on a difference between the forward path analog output and the feedforward path analog output. Proposed apparatus allows selecting a combination of the first and second transfer functions so that, when each is applied in its respective path, the residue signal passed to further stages of an ADC is reduced.

Reducing residue signals in analog-to-digital converters

Various examples are directed to crosspoint switches and methods of use thereof. An example cross point switch comprises a first row buffer, a second row buffer, a first column buffer, and a second column buffer. The crosspoint switch may also comprise a first switch that, when closed, electrically couples the second row buffer to the first column buffer, and a correction controller. The correction controller may be configured to send a first correction signal to the first row buffer; send a second correction signal to the second row buffer; receive an indication that the first switch is closed; send a third correction signal to the first column buffer; and send a fourth correction signal to the second column buffer.

A wide common-mode range receiver includes an input module, voltage level shift module, voltage level shift control module, and output module. The receiver can also include an equalizer. The receiver translates data originating from a circuit powered from an external voltage supply to a circuit powered by an internal voltage supply. The voltage level shift may be scaled based on differences between the voltage supplies or by determining the difference between an input common-mode voltage and a reference voltage, and driving a servo based on the difference.

Wide common-mode range receiver

Apparatus and methods for clock and data recovery (CDR) are provided herein. In certain configurations, a first CDR circuit captures data and edge samples from a first input data stream received over a first lane. The data and edge samples are used to generate a master phase signal, which is used to control a phase of a first data sampling clock signal used for capturing the data samples. Additionally, the first CDR circuit generates a master phase error signal based on changes to the master phase signal over time, and forwards the master phase error signal to at least a second CDR circuit. The second CDR circuit processes the master phase error signal to generate a slave phase signal used to control a phase of a second data sampling clock signal used for capturing data samples from a second input data stream received over a second lane.

Apparatus and methods for clock and data recovery

Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer can include a programmable gain amplifier (PGA) block which includes an input node configured to receive the input signal; an output node; and a programmable gain amplifier (PGA). The PGA amplifies the input signal with an adjustable gain. The PGA block also includes a gain control block having an input electrically coupled to the input node. The gain control block is configured to adjust the gain of the PGA at least partly in response to the input signal from the input node such that the PGA generates an output signal with a substantially constant amplitude envelope to the output node.

Methods for digitally-controlled automatic gain amplification

Apparatus and methods for frequency compensation of an amplifier are provided. In one embodiment, an integrated circuit (IC) includes an amplifier configured to amplify an input signal to generate an output signal. The IC further includes an output pad configured to receive an output signal from the amplifier and a control pad for controlling the closed-loop bandwidth of the amplifier. A compensation capacitor is electrically connected between an input of the inverting amplification block and an output of the inverting amplification block, and a switchable capacitor is electrically connected between the input of the inverting amplification block and the control pad. The control pad can be electrically connected to a DC voltage source or to the output pad to control the amplifier's closed-loop bandwidth.

Apparatus and methods for frequency compensation of an amplifier

Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer includes a first node configured to receive the input signal; a second node; and a programmable gain amplifier (PGA) having an adjustable gain. The PGA has an input electrically coupled to the first node, and an output electrically coupled to a third node. The equalizer also includes a high pass filter (HPF) having an input electrically coupled to the third node, and an output electrically coupled to the second node; and a control block configured to adjust one or more of the PGA or the HPF at least partly in response to a PGA output signal from the PGA or an HPF output signal from the HPF.

Apparatus and method for digitally-controlled adaptive equalizer

Apparatus and methods for equalization are provided. In one embodiment, an apparatus for equalizing an input voltage includes a first capacitor and a first resistor having a first end and a second end, the first end configured to receive the input voltage. The apparatus further includes a second resistor having a first end electrically connected to the second end of the first resistor at an output node. The apparatus further includes an inverting voltage buffer for substantially inverting the input voltage to generate an inverted input voltage. The apparatus further includes a transconductance buffer for receiving the inverted input voltage and for generating a current from a first end of the first capacitor to the output node having a magnitude equal to about the magnitude of the input voltage signal divided by the impedance of the first capacitor.

Apparatus and method for equalization

Apparatus and method for digitally-controlled automatic gain amplification

As provided herein, in some embodiments, power consumption and/or chip area is reduced by bias circuits configured to provide bias conditions for more than one active circuit, thereby reducing the number of bias circuits in a design. Shared bias circuits may reduce the aggregate amount of on-chip area utilized by bias circuitry and may also reduce the total power consumption of a chip. Additionally and/or alternatively, bias circuits disclosed herein are configured to provide outputs that are less susceptible to changes in the voltage supply level. In particular, in some embodiments, bias circuits are configured to provide relatively constant bias conditions despite changes in the voltage supply level. In some embodiments, bias circuits are configured to provide bias conditions that compensate for perturbations caused by changes other inputs, in order to stabilize a particular operating point.

Apparatus and method for electrical biasing

As provided herein, in some embodiments, power consumption and/or chip area is reduced by bias circuits configured to provide bias conditions for more than one active circuit, thereby reducing the number of bias circuits in a design. Shared bias circuits may reduce the aggregate amount of on-chip area utilized by bias circuitry and may also reduce the total power consumption of a chip. Additionally and/or alternatively, bias circuits disclosed herein are configured to provide outputs that are less susceptible to changes in the voltage supply level. In particular, in some embodiments, bias circuits are configured to provide relatively constant bias conditions despite changes in the voltage supply level. A bias circuit arrangement with an output substantially decoupled from changes in the voltage supply level may provide a more stable operating point in an active circuit. In some embodiments, bias circuits are configured to provide bias conditions that compensate for perturbations caused by changes other inputs, in order to stabilize a particular operating point.

Apparatus and method configured to provide electrical bias

An input bias current reduction circuit for multiple input stages having a common input includes a plurality of input stages each including a first input transistor with its base connected to the common input and the first current sensing transistor with its collector-emitter in series with the collector-emitter of the first input transistor and its base current replicating that of the first transistor; and a current compensation circuit for sensing the base current of the first current sensing transistor in each input stage and subtracting that from the base current of the first input transistor in each input stage for maintaining constant reduced current loading of the input.

Growing community of inventors

Lincoln, MA, United States of America

Kimo Tam