Analog Devices International Unlimited Company

Analog Devices Global

Analog Devices Global Unlimited Company

Venkata Aruna Srikanth Nittala

Avinash Gutta

Abhilasha Kawle

Roberto Sergio Matteo Maurino

Christopher Peter Hurrell

Abhishek Bandyopadhyay

Andrew Joseph Thomas

Sanjay Rajasekhar

Roberto S Maurino

Naiqian Ren

Bhargav R Vyas

Debopam Banerjee

Mayur Anvekar

Rajasekar Rajendran

Mayank Devam

An amplifier circuit comprises a first amplifier circuit stage including input devices connected to inputs of the amplifier circuit, a second amplifier circuit stage coupled to the first amplifier stage, a common mode extraction circuit configured to extract a DC common mode voltage of the first amplifier stage, and a bias circuit configured to bias one or more output devices of the second amplifier circuit stage using the DC common mode voltage.

Class A amplifier with push-pull characteristic

Systems, devices, and methods related to low-noise, high-accuracy single-ended continuous-time sigma-delta (CTSD) analog-to-digital converter (ADC) are provided. An example single-ended CTSD ADC includes a pair of input nodes to receive a single-ended input signal and input circuitry. The input circuitry includes a pair of switches, each coupled to one of the pair of input nodes; and an amplifier to provide a common mode signal at a pair of first nodes, each before one of the pair of switches. The single-ended CTSD ADC further includes digital-to-analog converter (DAC) circuitry; and integrator circuitry coupled to the input circuitry and the DAC circuitry via a pair of second nodes.

Low-noise, high-accuracy single-ended input stage for continuous-time sigma delta (CTSD) analog-to-digital converter (ADC)

A gain stage, such as an amplifier, e.g., an instrumentation amplifier, can receive an input signal and adjust the level of the input signal, e.g., amplify or attenuate. An output voltage of the gain stage can be applied to a subsequent circuit. Using various techniques, a second stage of an instrumentation amplifier, which can include a transconductance stage that converts a current to a voltage that can be applied to an output node of the instrumentation amplifier, can be removed. Removal of such a second stage can allow an output current from the gain stage to be applied directly from a current output node to an input node of a subsequent circuit.

Signal chain with current output gain stage followed by current input ADC

A reference buffer circuit comprises a dual-difference amplifier circuit including a first differential input, a second differential input, and a differential output that provides a differential reference signal; a first reference voltage coupled to a first input of the first differential input and a second reference voltage coupled to a first input of the second differential input; and wherein outputs of the differential output are connected by a feedback circuit path to second inputs of the first and second differential inputs.

Differential reference buffer for analog-to-digital converters

A voltage reference noise filter is provided that substantially eliminates noise with minimal external components for any circuit where the reference load current is a constant load and the circuit uses external components that have values that may vary with temperature, over time, and the like. The drift on an output of a voltage reference due to variation of resistor of the external filter is mitigated by moving the external resistor onto the chip containing the circuit. The voltage drop across the resistor is digitally compensated by a scaling factor determined during calibration. When more than one converter is provided on the chip, a further adjustment to the outputs of the converters is made based on the number of converters powered on or off. Also, error in output of converters due to mismatch among the converters is digitally compensated by a further scaling factor.

Methods of filtering reference voltage noise

Techniques for a configurable analog-to-digital converter filter to ameliorate transfer function peaking or frequency response issues are provided. In an example, a front-end circuit of a processing circuit can include a resistor-capacitor filter including at least two capacitors and a switch circuit. The resistor-capacitor filter can couple an input analog signal to the processing circuit. The switch circuit can couple to a first capacitor of the at least two capacitors, and can selectively place a terminal of the first capacitor at a selected one of a plurality of distinct nodes of the resistor-capacitor filter to configure the circuit to address the peaking or frequency response issue.

Techniques for configurable ADC front-end RC filter

A continuous-time sigma delta modulator circuit includes a scaling circuit that scales an input analog signal by a selectable range of different scaling factors in order to change a range of signal levels of the input analog signal to a desired range of signal levels in a scaled analog signal prior to conversion of the scaled analog signal to a digital signal. The scaling factor is selected based on the range of signal levels of the input analog signal in order to provide signal levels of the scaled signal within a desired range. The scaling circuit maintains current flow of the input analog signal at a substantially constant level regardless of the different scaling factors that are used to scale the input analog signal.

Configurable input range for continuous-time sigma delta modulators

A delta sigma modulator circuit comprises a forward circuit path including a first integrator stage and an analog-to-digital converter (ADC) circuit, wherein a transfer function of the forward circuit path includes a signal gain element of m, wherein m is a positive integer; an input path to the first integrator stage, wherein a transfer function of the input path includes a signal gain element of l/m; and a feedback circuit path operatively coupled to an output of the ADC circuit and an inverting input of an op amp of the first integrator stage, wherein the feedback circuit path includes at least a first digital-to-analog converter (DAC) circuit and a transfer function of the feedback circuit path includes a signal gain element of l/m.

Power scaling a continuous-time delta sigma modulator

Techniques for synchronization between multiple sampling circuits using a single pin interface to control an output data rate are described. The frequency or rate of a signal on this pin can be automatically determined and used to accomplish the required output data rate. Also described are techniques for using a single pin interface that can allow a sampling device to operate either in a master mode that can generate data strobes, or in a slave mode that can receive a convert start signal. Also described are techniques for controlling bandwidth and throughput for individual channels in a multi-channel device using a single pin interface. For example, using various techniques of this disclosure, integer multiple rate control for other channels can be provided thereby providing varying ODR for different channels, which can also control the bandwidth of interest.

Circuits, systems, and methods for synchronization of sampling and sample rate setting

Apparatus and methods for autozero amplifiers are provided herein. In certain configurations, an autozero amplifier includes at least three transconductance stages and an autozero timing control circuit configured to control an autozero sequence of the transconductance stages. The autozero timing control circuit can stagger autozeroing of the transconductance stages, such that a relatively small amount of the amplifier's amplification circuitry is connected to or disconnected from the amplifier's signal path at any given time. For example, in certain configurations, when one of the transconductance stages in autozeroed over a particular time interval, the remaining transconductance stages can operate in parallel to provide amplification during that time interval.

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Bengaluru, India

Venkata Aruna Srikanth Nittala