Home | Links | Contact Us | More About Intellectual Property | Bookmark

Search patents:

Home

Coded

Digital-to-analog-converter-for-sigma-delta-modulator

Amplifier arrangement and method and voltage controlled amplifier and method

It is, accordingly, an object of the present invention to provide an electronic amplifier ...

Active noise and vibration control system

It is, therefore, an object of the present invention to provide an improved system for controlling ...

Method and apparatus for microwave predistorter linearizer with electronic tuning

In one aspect of the invention, a predistorter linearizer for use with a radio frequency amplifier ...

Spectral shaping of circuit errors in digital-to-analog converters

The present invention is a hardware-efficient DAC topology that can be used to achieve a variety of ...

Method and apparatus for suppressing tones induced by cyclic dynamic element matching (DEM) algorithms

The foregoing and other problems are overcome by methods and apparatus in accordance with ...

Method and apparatus for mismatched shaping of an oversampled converter

An embodiment of the present invention is directed to a method and apparatus for spectrally shaping ...

Spectral shaping dynamic encoder for a DAC

A tree-structured dynamic encoder in accordance with the invention generates an N-bit encoder ...

Gauge for remotely indicating the pressure of a subterranean formation

Referring to the drawings and first to FIG. 1, the portion of the gauge which is lowered into a ...

Down hole apparatus for sensing and storing values of physical parameters

It is a primary object of this invention to provide a subsurface, self-contained, self-powered, ...

Optical analog to digital converter

According to the teachings of the present invention, environmental condition responsive apparatus ...

Digital to analog converter for sigma delta modulator

Details

Inventors: Fattaruso, John W.;
Assignee: Texas Instruments Incorporated (Dallas, TX)
Primary Examiner: Young; Brian K.
Assistant Examiner:
Attorney, Agent or Firm: Garner; Jacqueline J., Donaldson; Richard L., Hiller; William E.

A second order sigma delta modulator (10) includes a digital to analog converter (26) that provides feedback for system modulation. The digital to analog converter (26) employs a dynamic element matching circuit (72) which randomly selects among main capacitors (C.sub.j) to reduce the effect of capacitor value mismatching. The digital to analog converter (26) also employs a self calibration circuit (80) to trim the values of the main capacitors (C.sub.j) to obtain better capacitor matching. During self calibration, a clock signal (f.sub.rand) driving a pseudo random number generator (74) of the dynamic element matching circuit (72) is reduced to assist in minimizing variance in a digital output signal for accurate calibration of the main capacitors (C.sub.j). Upon completion of calibration, the clock signal (f.sub.rand) is returned to a frequency coinciding with the modulator clock rate.

DETAILED DESCRIPTION In accordance with the present invention, a digital to analog converter is provided which substantially eliminates or reduces disadvantages and problems associated with prior digital to analog converters within sigma delta modulator systems.
The present invention includes a plurality of main circuit elements wherein each main circuit element corresponds to a separate bit of a received digital signal.
Dynamic element matching circuitry randomly selects among the main circuit elements in response to the received digital signal for generation of an analog signal.
Self calibration circuitry matches the main circuit elements such that they are calibrated to identical values.
The present invention provides various technical advantages over other digital to analog converters within the prior art.
For example, one technical advantage is in performing both circuit element calibration and circuit element matching to reduce the effect of component mismatching and achieve linearity for a multi-bit converter.
Another technical advantage is in providing a highly accurate, stable, and linear digital to analog converter for sigma delta modulation.
Other technical advantages are readily apparent to one skilled in the art from the following descriptions, Figures, and claims.

Related patents

	Digital-to-analog converter with digital linearity correction In accordance with a basic aspect of the present invention, there is provided a method of operating a digital-to-analog converter. The method includes the steps of: ...
	Pulse generating circuit for dynamic random access memory device Accordingly, the present invention is directed to a pulse generating circuit for dynamic random access memory device that substantially obviates one or more of problems ...
	Low voltage latch with uniform stack height According to one embodiment of the invention, latch components are comprised of low threshold transistors. In addition, according to one embodiment of the invention, to ...
	Remote controlled thermostat OF THE PREFERRED EMBODIMENT The present invention is a method and apparatus for remotely adjusting the temperature of a building. Referring to FIG. 1, the apparatus ...
	*WITHDRAWN PATENT AS PER THE LATEST USPTO WITHDRAWN LIST* * NO IMAGES AVAILABLE* Description:...
	A/D signal conversion based on a comparison of voltage-divided signals FIG. 1 is a block diagram of portions of flash analog-to-digital (A/D) converter 1 according to some embodiments. A/D converter 1 includes resistor string 10, which in ...
	Rectangular wave pulse generators The circuit illustrated in FIG. 1 comprises an oscillator 10 which provides a periodic output signal (waveform (a) in FIGS. 2A and 2B) which is stable in frequency, as ...
	Method of making master slice type integrated circuit device It is hence a primary object of this invention to present master slice type integrated circuit device and manufacturing method thereof capable of solving the above-...
	Circuit and method for generating a clock signal In accordance with the teachings of the present invention, a circuit and method for generating a clock signal are provided. The clock generator circuit includes a ...
	Dynamic voltage reference which compensates for process variations The present invention concerns a dynamic voltage reference circuit for generating one or more control signals for use in controlling a delay circuit or other circuit ...

0.004
Archive: All patents - Links Copyright (c)2006 Eipa-patents.org - All rights reserved