Abstract: A continuous time sigma delta analog to digital converter is provided. The continuous time sigma delta analog to digital converter may include, but is not limited to, an analog to digital converter having a feedback loop, and a feedback loop controller coupled to the analog to digital converter, the feedback loop controller configured to adjust delay in the feedback loop by controlling a variable delay component in the feedback loop.

Abstract: A quantizer includes a voltage reference network and a set of comparators coupled with the voltage reference network. The voltage reference network generates a plurality of reference voltages. Each of the comparators receives an input signal and produces a sequence of digital samples. The set of comparators includes first, second, and third subsets of comparators. Each comparator of the first subset includes a switched capacitor stage, each comparator of the second subset includes a preamplifier stage, and each comparator of the third subset includes a switched capacitor stage. The first and third subsets of comparators compares the input signal with reference voltages corresponding to the upper and lower voltage ranges of the input signal, and the second subset of comparators compares the input signal with reference voltages corresponding to the middle voltage range of the input signal.

Abstract: A quantizer includes a voltage reference network and a set of comparators coupled with the voltage reference network. The voltage reference network generates a plurality of reference voltages. Each of the comparators receives an input signal and produces a sequence of digital samples. The set of comparators includes first, second, and third subsets of comparators. Each comparator of the first subset includes a switched capacitor stage, each comparator of the second subset includes a preamplifier stage, and each comparator of the third subset includes a switched capacitor stage. The first and third subsets of comparators compares the input signal with reference voltages corresponding to the upper and lower voltage ranges of the input signal, and the second subset of comparators compares the input signal with reference voltages corresponding to the middle voltage range of the input signal.

Abstract: A digital to analog converter including a current steering source and a master replica bias network. The current steering source includes a data current source providing a source current to a source node, a switch circuit operative to steer the source current to a selected one of first and second control nodes based on a data bit, a buffer circuit that buffers the source current between the first control node and a first current output node or between the second control node and a second current output node, and an activation current source provides activation current to the buffer circuit via the first and second control nodes. The master replica bias network replicates biasing of the buffer circuit relative to a replica control node and drives the buffer circuit to maintain the first control node, the second control node and the replica control node at a common master control voltage.

Abstract: A digital to analog converter including at least one current steering source and a master replica bias network. Each current steering source includes a data current source, two switches, two buffer devices, and two activation current sources. The switches are controlled by a data bit and its inverse for switching the source current between first and second control nodes. The buffer devices buffer the control nodes between corresponding output nodes. The activation current sources ensure that each buffer device remains active regardless of the state of the switches. The master replica bias network includes a replica buffer device coupled to a replica control node and a master buffer amplifier. The master buffer amplifier drives the first, second and replica buffer devices in parallel to maintain the first, second and replica control nodes at a common master control voltage to minimize noise and glitches at the output.

Abstract: A continuous time sigma delta analog to digital converter is provided. The continuous time sigma delta analog to digital converter may include, but is not limited to, an analog to digital converter having a feedback loop, and a feedback loop controller coupled to the analog to digital converter, the feedback loop controller configured to adjust delay in the feedback loop by controlling a variable delay component in the feedback loop.

Abstract: Embodiments of vehicle-borne radar systems and methods of their operation are provided. The vehicle-borne radar system includes a transmit path and a first receive path. The transmit path is capable of producing a signal for transmission over an air interface (e.g., a frequency modulated continuous wave (FMCW) signal). The receive path includes a continuous-time (CT) sigma delta analog-to-digital converter (ADC), and the receive path is capable of receiving a reflected version of the signal from the air interface, and converting the reflected version along the receive path into a sequence of digital samples using the CT sigma delta ADC. In an embodiment, the transmit path and the receive path are integrated onto a single integrated circuit.

Abstract: A comparator is provided. In one embodiment, a method of operating a comparator comprises providing a bias current (920); comparing an input signal and a reference signal to determine a difference signal and an inverted difference signal (930); latching the difference signal and the inverted difference signal to generate a first and second latched signals (950); generating a control signal using at least the first and second latched signals (970); and controlling the bias current in response to the control signal (980), wherein the comparing the input signal and the reference signal (930) is activated and deactivated in response to the controlling the bias current (980).

Abstract: Embodiments of apparatus and methods for applying a gain to an input signal are provided. An embodiment of a switched-capacitor gain stage circuit includes an input node, an output node, an operational amplifier, a correlated-double-sampling portion, a correlated-level-shifting portion, and a switching configuration. The operational amplifier has a first amplifier input, a second amplifier input, and an amplifier output. The correlated-double-sampling portion includes a plurality of sampling capacitors arranged in parallel and selectively coupled between the input node and a central node, and an offset storage capacitor including a first terminal coupled to the first amplifier input. The correlated-level-shifting portion includes a correlated-level-shifting capacitor including a first terminal coupled to the output node.

Abstract: A semiconductor device comprises a plurality of transistor mismatch circuits formed on a semiconductor wafer; and a characterization circuit formed on the semiconductor wafer. The characterization circuit is coupled to receive input provided by the absolute value circuits simultaneously which themselves receive inputs from the mismatch circuits simultaneously and is configured to output a standard deviation of mismatch between transistors in the mismatch circuits.

Abstract: An analog-to-digital converter (ADC) includes a continuous time filter, a quantizer, a continuous time digital-to-analog converter, a discrete time DAC, and a switch. The quantizer has an input terminal coupled to the output terminal of the continuous time filter, and a plurality of output terminals. The continuous time DAC has a plurality of input terminals coupled to the plurality of output terminals of the quantizer, and an output terminal. The discrete time DAC has a plurality of input terminals coupled to the plurality of output terminals of the quantizer, and an output terminal. The switch has a first input terminal coupled to the output terminal of the continuous time DAC, a second input terminal coupled to the output terminal of the discrete time DAC, and an output terminal coupled to the input terminal of the continuous time filter.

Abstract: An analog-to-digital converter (ADC) includes a continuous time filter, a quantizer, a continuous time digital-to-analog converter, a discrete time DAC, and a switch. The quantizer has an input terminal coupled to the output terminal of the continuous time filter, and a plurality of output terminals. The continuous time DAC has a plurality of input terminals coupled to the plurality of output terminals of the quantizer, and an output terminal. The discrete time DAC has a plurality of input terminals coupled to the plurality of output terminals of the quantizer, and an output terminal. The switch has a first input terminal coupled to the output terminal of the continuous time DAC, a second input terminal coupled to the output terminal of the discrete time DAC, and an output terminal coupled to the input terminal of the continuous time filter.

Abstract: A comparator is provided. In one embodiment, a method of operating a comparator comprises providing a bias current (920); comparing an input signal and a reference signal to determine a difference signal and an inverted difference signal (930); latching the difference signal and the inverted difference signal to generate a first and second latched signals (950); generating a control signal using at least the first and second latched signals (970); and controlling the bias current in response to the control signal (980), wherein the comparing the input signal and the reference signal (930) is activated and deactivated in response to the controlling the bias current (980).

Abstract: Embodiments of apparatus and methods for applying a gain to an input signal are provided. An embodiment of a switched-capacitor gain stage circuit includes an input node, an output node, an operational amplifier, a correlated-double-sampling portion, a correlated-level-shifting portion, and a switching configuration. The operational amplifier has a first amplifier input, a second amplifier input, and an amplifier output. The correlated-double-sampling portion includes a plurality of sampling capacitors arranged in parallel and selectively coupled between the input node and a central node, and an offset storage capacitor including a first terminal coupled to the first amplifier input. The correlated-level-shifting portion includes a correlated-level-shifting capacitor including a first terminal coupled to the output node.

Abstract: A converter (200) adapted to convert an analog input signal into a digital output signal includes an analog input terminal (205) for receiving the analog input signal, a Redundant Signed Digit (RSD) stage (210) coupled to the analog input terminal, and a digital section (220). The RSD stage is configured to receive the analog input signal at the analog input terminal, produce a first number of bits at a digital output from the analog input signal during a first half of a first clock cycle, provide a residual feedback signal of the analog input signal at the analog input terminal during a second half of the first clock cycle, and produce a second number of bits at the digital output from the residual feedback signal during a first half of a second clock cycle, the second number of bits less than the first number of bits.

Abstract: A converter (200) adapted to convert an analog input signal into a digital output signal includes an analog input terminal (205) for receiving the analog input signal, a Redundant Signed Digit (RSD) stage (210) coupled to the analog input terminal, and a digital section (220). The RSD stage is configured to receive the analog input signal at the analog input terminal, produce a first number of bits at a digital output from the analog input signal during a first half of a first clock cycle, provide a residual feedback signal of the analog input signal at the analog input terminal during a second half of the first clock cycle, and produce a second number of bits at the digital output from the residual feedback signal during a first half of a second clock cycle, the second number of bits less than the first number of bits.

Abstract: Apparatus are provided for continuous-time sigma-delta modulators. A sigma-delta modulator comprises a quantizer configured to convert an analog signal to a digital value. A main feedback arrangement is coupled to the quantizer, and the main feedback arrangement delays the digital value by a first delay period and generates a main feedback signal based on the delayed value. A compensation feedback arrangement is coupled to the quantizer, and compensation feedback arrangement delays the digital value by a second delay period and generates a compensation feedback signal based on the delayed value. A forward signal arrangement produces the analog signal at the quantizer based on an input signal, the main feedback signal, and the compensation feedback signal. The second delay period is independent of and is not influenced by the first delay period, and the second delay period is chosen such that the compensation feedback signal compensates for the first delay period.

Abstract: Apparatus and methods are provided for converting an analog input signal to a digital output value. A quantization circuit comprises an input node and a comparator array, wherein each comparator of the comparator array is coupled to the input node. A voltage divider arrangement is coupled to the comparator array and configured to establish a respective threshold voltage for each comparator of the comparator array. The comparator array generates a digital code based on the input signal and the respective threshold voltage for each comparator. A control node is coupled to the voltage divider arrangement, wherein the control node and the voltage divider arrangement are cooperatively configured to adjust the threshold voltage for at least one comparator of the comparator array in response to a control signal at the control node.

Abstract: Apparatus are provided for continuous-time sigma-delta modulators. A sigma-delta modulator comprises a quantizer configured to convert an analog signal to a digital value. A main feedback arrangement is coupled to the quantizer, and the main feedback arrangement delays the digital value by a first delay period and generates a main feedback signal based on the delayed value. A compensation feedback arrangement is coupled to the quantizer, and compensation feedback arrangement delays the digital value by a second delay period and generates a compensation feedback signal based on the delayed value. A forward signal arrangement produces the analog signal at the quantizer based on an input signal, the main feedback signal, and the compensation feedback signal. The second delay period is independent of and is not influenced by the first delay period, and the second delay period is chosen such that the compensation feedback signal compensates for the first delay period.

Abstract: Apparatus and methods are provided for converting an analog input signal to a digital output value. A quantization circuit comprises an input node and a comparator array, wherein each comparator of the comparator array is coupled to the input node. A voltage divider arrangement is coupled to the comparator array and configured to establish a respective threshold voltage for each comparator of the comparator array. The comparator array generates a digital code based on the input signal and the respective threshold voltage for each comparator. A control node is coupled to the voltage divider arrangement, wherein the control node and the voltage divider arrangement are cooperatively configured to adjust the threshold voltage for at least one comparator of the comparator array in response to a control signal at the control node.