Freescale Semiconductor,inc.

Nxp Usa, Inc.

Rex Kenton Hales

Olivier Vincent Doare

Cristian Pavao-Moreira

Bruce Michael Newman

An analog-to-digital converter (ADC) and a method are disclosed. The ADC has a quantizer. The quantizer comprises a linear-feedback shift register (LFSR), a decoder configured to provide a plurality of switch control signals at a plurality of decoder outputs, respectively, the plurality of switch control signals responsive to a LFSR value of the LFSR output; an electrical reference, the electrical reference having a plurality of reference outputs, the electrical reference configured to provide a plurality of reference levels at the plurality of reference outputs, respectively; a first switch providing a first switch output and a second switch output; and a comparator, the comparator having a signal input, a first reference input, and a second reference input, the first reference input connected to the first switch output, and the second reference input connected to the second switch output.

Mismatch compensation in an analog-to-digital converter using reference path reconfiguration

A device includes a variable gain amplifier, a voltage shifter, a variable gain amplifier half replica module, and an analog to digital converter. The variable gain amplifier includes an input terminal to receive an input signal, an output terminal to provide a first output signal that is biased based on a first common-mode voltage reference. The voltage shifter circuit includes first and second input terminals, and an output terminal to provide, to the analog to digital converter, a third output signal that is biased based on a second common-mode voltage reference. The variable gain amplifier half replica module includes an output terminal coupled to the second input terminal of the voltage shifter circuit, the variable gain amplifier half replica module to control the third output signal of the voltage shifter circuit based on the first common-mode voltage reference and the second common-mode voltage reference.

System and method to directly couple to analog to digital converter having lower voltage reference

The test signal generator generates an analog and digital test signals to test a sigma-delta ADC which has an analog portion succeeded by a digital decimation filter. The test signal generator supplies a first digital test signal having a first particular number of bits N and a first particular bit rate RN corresponding to digital signals occurring after the digital decimation filter. A digital sigma-delta modulator converts the first digital test signal into a second digital test signal having a second particular number of bits M&#x3c;N thereby corresponding to a digital signal occurring at an input of the digital decimation filter. A DAC converts the second digital test signal into an analog signal, and a filter to filter the analog signal to obtain an analog test signal for testing the analog portion.

Test signal generator for sigma-delta ADC

The circuit generates an analog output signal which may be used to test a sigma-delta ADC. A digital waveform generator supplies a digital signal to a DAC to convert the digital signal into an analog signal. A filter filters the analog signal to obtain the analog output signal. The DAC is a DAC of a sigma-delta ADC and the filter comprises a filter of the sigma/delta ADC. A multiplexersupplies the digital signal to the DAC in a generator mode wherein the circuit converts the digital signal into the analog output signal using the part of the sigma-delta ADC, or to supply a quantized analog output signal to the DAC in normal mode wherein the sigma-delta ADC converts its analog input signal into the quantized analog output signal.

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Mesa, AZ, United States of America

Rex Kenton Hales