1
David Norris, Jeffrey M Blumenthal, Geoffrey E Brehmer, Glen W Brown, Carlin Dru Cabler, Ryan Feemster, David Guercio, Dale E Gulick, Larry D Hewitt, Michael Hogan, Alfredo R Linz, Paul G Schnizlein, Martin P Soques, Michael E Spak, David N Suggs, Alan T Torok: Monolithic PC audio circuit with enhanced digital wavetable audio synthesizer. Advanced Micro Devices, Fulbright & Jaworski L, August 19, 1997: US05659466 (159 worldwide citation)

A digital wavetable audio synthesizer is described. The synthesizer can generate up to 32 high-quality audio digital signals or voices, including delay-based effects, at either a 44.1 KHz sample rate or at sample rates compatible with a prior art wavetable synthesizer. The synthesizer includes an ad ...


2
Carlin Dru Cabler, Alfredo R Linz: Delta-sigma ADC with multi-stage decimation filter and gain compensation filter. Advanced Micro Devices, Fulbright & Jaworski L, July 8, 1997: US05646621 (107 worldwide citation)

An analog-to-digital conversion circuit is described which includes a front end sigma-delta modulator circuit, a multi-stage digital decimation filter circuit, and a digital compensation filter circuit. An overrange detect circuit is also provided.


3
Safdar M Asghar, Alfredo R Linz: Frequency controlled recursive oscillator having sinusoidal output. Advanced Micro Devices, Foley & Lardner, April 20, 1993: US05204642 (91 worldwide citation)

An apparatus is disclosed for generating an output signal in response to an input signal having a variable input level. The output signal has an output frequency which varies to represent variations in the input level. The apparatus comprises a processing circuit for implementing a digital signal pr ...


4
Alfredo R Linz: Arrangement for asynchronous decimation using a frequency ratio estimator and method thereof. Advanced Micro Devices, Merchant & Gould P C, December 21, 1999: US06005901 (50 worldwide citation)

A communication system includes a data sampling rate converter that uses a closed-loop control arrangement to convert an input signal at a first sampling rate to a second, asynchronous, sampling rate without requiring extensive output buffering. A small number of data registers in a first-in-first-o ...


5
Carlin D Cabler, Alfredo R Linz: Multi-stage digital to analog conversion circuit and method. Advanced Micro Devices, Fulbright & Jaworski L, December 17, 1996: US05585802 (44 worldwide citation)

This invention is for a digital-to-analog conversion circuit (DAC) which includes an interpolation filter circuit, a noise shaper circuit and a semi-digital FIR filter circuit. The entire DAC circuit provides noise shaping, analog filtering and oversampling functions.


6
Alfredo R Linz: Digital interpolation circuit for a digital-to-analog converter circuit. Advanced Micro Devices, Fulbright & Jaworski L, November 26, 1996: US05579004 (38 worldwide citation)

A digital interpolation circuit is described which has a first interpolation stage, a second interpolation stage, a third interpolation stage and a noise shaping stage. The first stage oversamples a multi-bit digital input signal to twice the sample rate of the multi-bit signal. The second stage ove ...


7
Alfredo R Linz: Frequency ratio estimation arrangement and method thereof. Advanced Micro Devices, Williams Morgan & Amerson, May 9, 2000: US06061410 (35 worldwide citation)

A communication system includes a data sampling rate converter that uses a closed-loop control arrangement to convert an input signal at a first sampling rate to a second, asynchronous, sampling rate without requiring extensive input buffering. A number of data registers in a first-in-first-out inpu ...


8
Alfredo R Linz, Glen Brown: Digital decimation and compensation filter system. Advanced Micro Devices, Fulbright & Jaworski L, April 15, 1997: US05621675 (21 worldwide citation)

This invention is for a multi-stage digital decimation filter, which includes a sinc.sup.6 filter, a half-band linear phase FIR filter and a symmetric, linear phase, FIR filter and a digital compensation filter. The multi-stage decimation filter down-samples the output of a sigma-delta modulator by ...


9
Alfredo R Linz: Digital noise shaper circuit. Advanced Micro Devices, Fulbright & Jaworski L, January 28, 1997: US05598158 (21 worldwide citation)

A digital noise shaper circuit is provided which includes a signal transfer function and a noise transfer function, with associated coefficients and gain scaling factors, which ensures a predetermined frequency response, signal passband and noise stopband, and which converts a multi-bit digital sign ...


10
Alfredo R Linz: Method and apparatus for generating tones in a multi-tone modem. Legerity, Williams Morgan & Amerson, April 17, 2001: US06219377 (15 worldwide citation)

A method and modem is provided for communicating data using a plurality of tones. The modem includes an IFFT unit capable of providing a signal comprising a plurality of tones, an interpolator capable of interpolating the signal to produce an interpolated signal, and a tone adder capable of adding a ...