Freescale Semiconductor,inc.

Motorola Corporation

Intel Corporation

Fujitsu Semiconductor Limited

Mcafee, Inc.

Merit Y Hong

David B Harnishfeger

Kris Kaufman

Robert Bruce Davies

Brandt Braswell

David Edward Bien

Andreas A Wild

James S Caravella

Mohammad Nizam U Kabir

Bruce Michael Newman

Zhou Zhixu

Julian Aschieri

James Riches

Julian G Ashieri

A temperature measurement system is disclosed. In accordance with some embodiments of the present disclosure, a temperature measurement system may comprise a resistor, a thermistor, a resistance-to-current converter configured to generate a current signal based on a resistance, an analog-to-digital converter (ADC) configured to receive a first current signal based on the resistor, convert the first current signal into a first digital signal, receive a second current signal based on the thermistor, and convert the second current signal into a second digital signal, and a calculation stage communicatively coupled to an ADC output and configured to determine a first digital value based on the first digital signal, determine a second digital value based on the second digital signal, calculate a resistance ratio based on the first digital value and the second digital value, and determine a temperature output value based on the resistance ratio.

Temperature measurement system

In accordance with some embodiments of the present disclosure, a calibrated temperature measurement system comprises a resistor, a thermistor, a resistance-to-current converter configured to generate a current signal based on a resistance, and an analog-to-digital converter (ADC) configured to receive a first current signal based on the resistor, convert the first current signal into a first digital signal, receive a second current signal based on the thermistor, and convert the second current signal into a second digital signal. A memory may comprise resistor-characterization information. A calculation stage communicatively coupled to an ADC output may be configured to determine a first digital value based on the first digital signal, determine a second digital value based on the second digital signal, calculate a resistance ratio based on the first digital value and the second digital value, and determine a temperature output value based on the resistance ratio and the resistor-characterization information.

Calibrated temperature measurement system

A temperature-measurement input stage may include a resistor, a thermistor, a first multiplexor, an amplifier, a second multiplexor, and an output stage. The first multiplexor may be configured to couple the resistor to a first amplifier input during a first multiplexor state, and couple the thermistor to the first amplifier input during a second multiplexor state. The amplifier may comprise the first amplifier input, a second amplifier input coupled to a voltage reference, and an amplifier output coupled to a feedback path. The second multiplexor may be configured to route a feedback current to the resistor during the first multiplexor state and route the feedback current to the thermistor during the second multiplexor state. The output stage may be configured to provide an output current based on the feedback current.

Input stage for temperature measurement system

A continuous time delta-sigma modulator is provided that includes an integrator stage including a plurality of integrators; a quantizer to receive an input signal from the integrator stage and output a quantizer signal; a global feedback path providing feedback from the quantizer to the integrator stage; a local feedback path connecting the quantizer and a preceding integrator of the integrator stage configured to compensate for delay attributed to the global feedback path; and a delay compensation circuit. The delay compensation circuit is configured to calculate a delay value based on sources of additional delay within a local feedback loop, and to supply the additional delay value to the quantizer to compensate for delay within the local feedback loop.

Delay compensation for sigma delta modulator

A differential amplifier circuit with common-mode feedback is disclosed. The amplifier may include a first stage comprising a first differential input configured to drive a first differential pair transistor in a first differential current path, a second differential input configured to drive a second differential pair transistor in a second differential current path, a first differential output, and a second differential output, a second stage comprising a first differential input, a second differential input, a first differential output, and a second differential output, a common-mode feedback circuit, a first conducting element in a first common-mode current path parallel to the first differential current path and comprising a first conducting terminal coupled to the first differential output of the first stage, and a second conducting element in a second common-mode current path parallel to the second differential current path and comprising a first conducting terminal coupled to the second differential output of the first stage.

Common-mode feedback circuit

A circuit includes a clock conditioning circuit which receives an encoded clock signal, and provides first and second conditioned clock signals in response. The clock conditioning circuit adjusts a period of the first and second conditioned clock signals in response to an adjustment of a period of the encoded clock signal. The circuit includes a modulator which receives the first and second conditioned clock signals.

Clock conditioning circuit

Embodiments include integrator systems, switched-capacitor circuits, and methods of their operation. An integrator system comprises a differential amplifier and first and second sampling modules. The first sampling module includes a first capacitor and a first set of switches. The first set of switches changes a connection status between the first capacitor and first and second amplifier input terminals when a change in a polarity of a differential input signal does not occur between consecutive switching cycles, and refrains from changing the connection status when the change in the polarity does occur. The second sampling module includes a second capacitor and a second set of switches. The second set of switches changes a connection status between the second capacitor and the first and second amplifier input terminals when the change in the polarity does occur, and refrains from changing the connection status when the change in the polarity does not occur.

Switched-capacitor circuits, integration systems, and methods of operation thereof

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.

Digitally adjustable quantization circuit

A technique for implementing compensatory feedback in a continuous-time sigma-delta modulator includes providing, based on an analog input signal, a digital output signal at an output of a quantizer circuit of the continuous-time sigma-delta modulator. A functionality of the quantizer circuit is then controlled based on the digital output signal.

Techniques for delay compensation of continuous-time sigma-delta modulators

An integrator circuit () is provided including an amplifier element () configured to receive an input signal at an input node, amplify the input signal, and provide an amplified input signal at an output node; a feedback capacitor element () connected between the output node and the input node; and a current matching circuit () connected to the output node, and configured to sense an output voltage of the amplifier element and to provide a supplemental current (I) to the input node that is less than or equal to a feedback current (I) charging the feedback capacitor element. This supplemental current is substantially equal and opposite in polarity to a feedback current when the output voltage satisfies a set criterion.

Sigma-delta modulator

A method and apparatus are provided for operating a feedback network (). The method and apparatus operate to combine () a feedback signal (I) and an incoming signal (V) to generate an adjusted signal (I) at an input node of an amplifier element (); amplifying the amplifier input signal in the amplifier element to produce an amplifier output signal (V) at an output node of the amplifier element; processing the amplifier output signal according to a feedback operation () to generate the feedback signal (I); and providing an assist current (, I) to the output node of the amplifier element, separate from an output current provided by the amplifier element.

System and method for operating a feedback network

Integrator current matching

A double-sampled feedback integrator system includes a sampling module having multiple switched capacitors. The switched capacitors of the integrator system are opened and closed based upon a polarity of the signal input to the double-sampled feedback integrator system. The integrator system can be used in a sigma-delta converter. A sigma-delta converter includes a double-sampled common-mode correction circuit having multiple switched capacitors to provide common-mode rejection to a system.

Double-sampled integrator system and method thereof

A series capacitive component for use in signal processing applications such as analog-to-digital (A/D) converters, switched capacitor circuits and the like that require matched capacitors is presented. A series capacitive component consists of multiple capacitors connected in series. By utilizing series capacitive components in integrated circuits, significantly lower loads are provided for the same resulting capacitor mismatch range as previous solutions. Additionally, for the same load and noise, using series capacitive components provides a substantially reduced match over previous solutions. Thus a circuit designer has more flexibility when making tradeoffs between circuit area and capacitor mismatch and therefore manufacturing yields.

Series capacitive component for switched-capacitor circuits consisting of series-connected capacitors

An improved method of filtering that can be used with an analog-to-digital converter (ADC) is disclosed herein. Multiple discrete-time-feedback-modules () each with current limiting (and) are used to sample information which is supplied to an integrator () for conversion to digital form. By overlapping the integration of these samples, and by evaluating these integration results multiple times (TPTPTP) per sample (TP), using the methods disclosed herein the advantages of increased accuracy, lower power consumption and reduced cost may be realized.

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Chandler, AZ, United States of America

Merit Y Hong