Nxp Usa, Inc.

Freescale Semiconductor,inc.

Mariam Hoseini

Mohammad Nizam Kabir

Brandt Braswell

Douglas Alan Garrity

Rakesh Shiwale

Doug Garrity

Bruce Michael Newman

Mark Stachew

A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a reference loading circuit uses a plurality of sampling switched capacitors connected in a switching configuration to selectively couple a first reference voltage and/or a second reference voltage to the central node by pre-charging the plurality of sampling switched capacitors with the first and second reference voltages during the sampling phase, and by coupling each of the first and second reference voltages to at least one of the plurality of sampling switched capacitors when connected to the central node during the gain phase.

Mismatch and reference common-mode offset insensitive single-ended switched capacitor gain stage with reduced capacitor mismatch sensitivity

Embodiments of a multi-stage clock generator architecture that generates multiple non-overlapping clock phase signals includes: a first stage clock generator configured to: divide an input clock signal into a number of clock signals, synchronize each clock signal to a transition edge of a synchronization signal to produce synchronized clock signals, wherein the synchronization signal is a delayed version of the input clock signal by at least an amount sufficient to ensure that each of the clock signals become stable in response to a transition edge of the input clock signal, and generate a number of clock phase signals based on the synchronized clock signals. The architecture also includes a later stage clock generator configured to: generate a set of mutually non-overlapping clock phase signals based on the input clock signal.

Clock generator for multi-channel analog to digital converter

A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a common-mode reference voltage generation circuit uses one or more additional sampling switched capacitors to selectively couple the first and second reference voltages to the amplifier input during the gain phase when the input voltage is between the high and low threshold voltages using a switching configuration of switches that are controllable to connect the sampling switched capacitors to the one or more central nodes in the sampling phase, and to connect the amplifier output in feedback to the input sampling circuit in the gain phase while simultaneously connecting the one or more central nodes to the first amplifier input.

Mismatch and reference common-mode offset insensitive single-ended switched capacitor gain stage

A digital to analog converter convert digital data in binary format to thermometer bit vectors. A first set of the thermometer bit vectors corresponds to most significant bits of the digital data and a second set of the thermometer bit vectors corresponds to least significant bits of the digital data. Connections of first current sources corresponding to the first set of the thermometer bit vectors and second current sources corresponding to the second set of the thermometer bit vectors are dynamically and randomly alternated to a first output line and a second output line. Calibration current is applied to the second current sources so a total current of the second current sources and the calibration current is within a predetermined range of an average current of the first current sources.

Digital to analog (DAC) converter with current calibration

Embodiments of a multi-channel analog to digital converter (ADC) include: a first multiplying digital to analog converter (MDAC) having: first and second switched capacitor circuit paths respectively coupled between first and second input nodes and an input node of a first gain element, a second MDAC having: third and fourth switched capacitor circuit paths respectively coupled between third and fourth input nodes and an input node of a second gain element, a third MDAC having: fifth and sixth switched capacitor circuit paths respectively coupled between a fifth input node and an input node of a third gain element, seventh and eighth switched capacitor circuit paths respectively coupled between a sixth input node and the input node of the third gain element, the fifth input node coupled to an output node of the first gain element, the sixth input node coupled to an output node of the second gain element.

Multi-channel analog to digital converter

A digital to analog converter including a current source for providing a master current, a first sub digital to analog converter coupled to the current source which generates a plurality of currents, and a second sub digital to analog converter coupled to at least one of the plurality of currents from the first sub digital to analog converter which generates a second plurality of currents. The digital to analog converter also includes an overlap adjustment circuit coupled with the second sub digital to analog converter which adds current. The digital to analog converter is configured to operate in a first mode for generating a sine wave with a first bit level accuracy and, when in the first mode, the overlap adjustment circuit adds no current. to the second sub digital to analog converter The digital to analog converter is configured to operate in a second mode for generating a ramp wave with a second bit level accuracy and, when in the second mode, the overlap adjustment circuit adds current to the second sub digital to analog converter. When in the second mode, the total current of the second sub digital to analog converter and the overlap converter is greater than one of the plurality of currents generated by the first sub digital to analog converter.

Digital-to-analog converter circuit

A sigma-delta (&#x3a3;&#x394;) analog-to-digital converter (ADC) comprises a main &#x3a3;&#x394; modulator configured to receive an analog input signal at a main &#x3a3;&#x394; modulator input and to provide a main digital output signal representative of the analog input signal and an auxiliary &#x3a3;&#x394; modulator configured to receive an auxiliary input signal at an auxiliary &#x3a3;&#x394; modulator input and to provide an auxiliary digital output signal, wherein the &#x3a3;&#x394; ADC comprises a shared integrator stage, the shared integrator stage is configured to be used by the main &#x3a3;&#x394; modulator and the auxiliary &#x3a3;&#x394; modulator, wherein, alternatingly, the shared integrator stage is selectively communicatively coupled to receive the analog input signal when configured to be used by the main &#x3a3;&#x394; modulator and selectively communicatively coupled to receive the auxiliary input signal when configured to be used by the auxiliary &#x3a3;&#x394; modulator.

Dual sigma-delta analog-to-digital converter

The embodiments described herein provide a digital-to-analog converter (DAC). The DAC implements a stepped return-to-zero (RZ) pulse scheme, where the DAC output includes the superposition of multiple time-offset RZ pulses. In one embodiment, the DAC includes a first switching element, a second switching element, a current source, and a current sink. The first switching element generates first RZ pulses, and the second switching element generates second RZ pulses, where the second RZ pulses are time-offset from the first RZ pulses. The first RZ pulses and second RZ pulses are combined to provide stepped RZ pulse output signal.

Return-to-zero digital-to-analog converter with overlapping time delayed pulse generation

A quantizer for an analog to digital converter has an input for receiving an analog input signal. A detector senses a common mode voltage component of the input signal. A reference voltage source produces a plurality of reference voltages. A voltage source biases the reference voltage source in response to the sensed common mode voltage component. Therefore, the common mode voltage in the input signal establishes the common mode voltage of the reference voltage source. A plurality of comparators are connected to the reference voltage source, wherein each of the plurality of comparators compares the input signal to one of the plurality of reference voltages and produces a output bit denoting a result of the comparing.

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San Mateo, CA, United States of America

Mariam Hoseini