Patents by Inventor David S. P. Ho
David S. P. Ho has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7783275Abstract: A direct conversion satellite tuner is fully integrated on a common substrate. The integrated tuner receives an RF signal having a plurality of channels and down-converts a selected channel directly to baseband for further processing. The integrated tuner includes on-chip local oscillator generation, tunable baseband filters, and DC Offset cancellation. The integrated tuner can be implemented in a completely differential I/Q configuration for improved electrical performance. The entire direct conversion satellite tuner can be fabricated on a single semiconductor substrate using standard CMOS processing, with minimal off-chip components. The tuner configuration described herein is not limited to processing TV signals, and can be utilized to down-convert other RF signals to an IF frequency or baseband.Type: GrantFiled: October 13, 2006Date of Patent: August 24, 2010Assignee: Broadcom CorporationInventors: Myles Wakayama, Dana Vincent Laub, Frank Carr, Afshin Mellati, David S. P. Ho, Hsiang-Bin Lee, Chun-Ying Chen, James Y. C. Chang, Lawrence M. Burns, Young Joon Shin, Patrick Pai, Iconomos A. Koullias, Ron Lipka, Luke Thomas Steigerwald, Alexandre Kral
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Patent number: 7139547Abstract: A direct conversion satellite tuner is fully integrated on a common substrate. The integrated tuner receives an RF signal having a plurality of channels and down-converts a selected channel directly to baseband for further processing. The integrated tuner includes on-chip local oscillator generation, tunable baseband filters, and DC Offset cancellation. The integrated tuner can be implemented in a completely differential I/Q configuration for improved electrical performance. The entire direct conversion satellite tuner can be fabricated on a single semiconductor substrate using standard CMOS processing, with minimal off-chip components. The tuner configuration described herein is not limited to processing TV signals, and can be utilized to down-convert other RF signals to an IF frequency or baseband.Type: GrantFiled: November 29, 2001Date of Patent: November 21, 2006Assignee: Broadcom CorporationInventors: Myles Wakayama, Dana Vincent Laub, Frank Carr, Afshin Mellati, David S. P. Ho, Hsiang-Bin Lee, Chun-Ying Chen, James Y. C. Chang, Lawrence M. Burns, Young Joon Shin, Patrick Pai, Iconomos A. Koullias, Ron Lipka, Luke Thomas Steigerwald, Alexandre Kral
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Patent number: 6950049Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.Type: GrantFiled: October 4, 2004Date of Patent: September 27, 2005Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller
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Patent number: 6930626Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: GrantFiled: July 20, 2004Date of Patent: August 16, 2005Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller, Eric Fogleman
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Publication number: 20040252042Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: ApplicationFiled: July 20, 2004Publication date: December 16, 2004Inventors: Todd L. Brooks, David S.P. Ho, Kevin L. Miller, Eric Fogleman
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Patent number: 6816097Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.Type: GrantFiled: March 6, 2003Date of Patent: November 9, 2004Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller
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Patent number: 6771199Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: GrantFiled: April 8, 2003Date of Patent: August 3, 2004Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller, Eric Fogleman
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Publication number: 20040021596Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: ApplicationFiled: April 8, 2003Publication date: February 5, 2004Applicant: Broadcom CorporationInventors: Todd L. Brooks, David S.P Ho, Kevin L. Miller, Eric Fogleman
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Patent number: 6628218Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: GrantFiled: September 12, 2001Date of Patent: September 30, 2003Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller, Eric Fogleman
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Publication number: 20030156051Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.Type: ApplicationFiled: March 6, 2003Publication date: August 21, 2003Applicant: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller
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Patent number: 6577261Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, a range signal is produced based on the digital input code. The range signal specifies which one of a plurality of ranges the digital input code is within. A density code is also produced, preferably, using a shuffling algorithm. The density code specifies a level within the range expressed by the range signal. The range signal and the density code are then combined to produce a plurality of sub-codes, a sum of the plurality of sub-codes equaling the digital input code.Type: GrantFiled: September 12, 2001Date of Patent: June 10, 2003Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller, Eric Fogleman
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Patent number: 6531973Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.Type: GrantFiled: September 12, 2001Date of Patent: March 11, 2003Assignee: Broadcom CorporationInventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller
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Publication number: 20020080053Abstract: The present invention is directed to a sigma-delta digital to analog converted (DAC) including a digital-sigma delta modulator, a decimation filter, and a multi-bit DAC. The digital sigma-delta modulator receives a digital input signal and produces a quantized digital signal therefrom. The decimation filter receives the quantized digital signal and produces a decimated digital signal therefrom. The multi-bit DAC receives the decimated digital signal and produces an analog output signal therefrom. The analog output signal is representative of the digital input signal.Type: ApplicationFiled: September 12, 2001Publication date: June 27, 2002Inventors: Todd L. Brooks, David S.P. Ho, Kevin L. Miller
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Publication number: 20020070887Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, a range signal is produced based on the digital input code. The range signal specifies which one of a plurality of ranges the digital input code is within. A density code is also produced, preferably, using a shuffling algorithm. The density code specifies a level within the range expressed by the range signal. The range signal and the density code are then combined to produce a plurality of sub-codes, a sum of the plurality of sub-codes equaling the digital input code.Type: ApplicationFiled: September 12, 2001Publication date: June 13, 2002Inventors: Todd L. Brooks, David S. P. Ho, Kevin L. Miller, Eric Fogleman
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Publication number: 20020063647Abstract: Methods and apparatuses for spectrally shaping mismatch errors in a multi-bit digital to analog converter (DAC). In an embodiment, the multi-bit DAC is constructed from K separate multi-element sub-DACs, where K and the number of elements in each sub-DAC are each preferably greater than two. A received digital input code is split into a set of K sub-codes corresponding to the digital input code. The set of K sub-codes can have one of at least N different sub-code orders that specify an order of each of the K sub-codes with respect to one another, where N>2. A sum of the K sub-codes equals the digital input code. One of the at least N different sub-code orders is selected using a shuffling algorithm. Then, each sub-code in the set of K sub-codes is output in accordance with the selected sub-code order.Type: ApplicationFiled: September 12, 2001Publication date: May 30, 2002Inventors: Todd L. Brooks, David S.P Ho, Kevin L. Miller, Eric Fogleman