Patents by Inventor Richard Schreier
Richard Schreier 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: 8536939Abstract: An operational amplifier can include a plurality of amplifiers connected to form a plurality of amplification paths extending from an input terminal to an output terminal of the operational amplifier. An amplifier in one of the amplification paths can include an intrinsic amplification-transistor capacitance connected between a first amplifier input and a first amplifier output, and a cross-coupling capacitor connected between the first amplifier input and a second amplifier output. A plurality of the amplification paths can include series-connected amplifiers connected in parallel with the cross-coupled amplifier. The cross-coupling capacitor can have a capacitance value selected as a function of the intrinsic capacitance and a gain experienced between the amplifier inputs and outputs. The operational amplifier can include an AC coupling capacitor connected in series with the cross-coupled amplifier. The operational amplifier can be arranged in feedback configuration.Type: GrantFiled: November 9, 2011Date of Patent: September 17, 2013Assignee: Analog Devices, Inc.Inventors: Hajime Shibata, Richard Schreier, Wenhua Yang
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Publication number: 20130113569Abstract: An operational amplifier can include a plurality of amplifiers connected to form a plurality of amplification paths extending from an input terminal to an output terminal of the operational amplifier. An amplifier in one of the amplification paths can include an intrinsic amplification-transistor capacitance connected between a first amplifier input and a first amplifier output, and a cross-coupling capacitor connected between the first amplifier input and a second amplifier output. A plurality of the amplification paths can include series-connected amplifiers connected in parallel with the cross-coupled amplifier. The cross-coupling capacitor can have a capacitance value selected as a function of the intrinsic capacitance and a gain experienced between the amplifier inputs and outputs. The operational amplifier can include an AC coupling capacitor connected in series with the cross-coupled amplifier. The operational amplifier can be arranged in feedback configuration.Type: ApplicationFiled: November 9, 2011Publication date: May 9, 2013Applicant: ANALOG DEVICES, INC.Inventors: Hajime SHIBATA, Richard SCHREIER, Wenhua YANG
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Patent number: 8410962Abstract: An active RC resonator includes a first operational amplifier having first and second inputs and first and second outputs, a second operational amplifier having first and second inputs and first and second outputs, a first resistor coupled between the first input of the first operational amplifier and the second output of the second operational amplifier, a second resistor coupled between the second input of the first operational amplifier and the first output of the second operational amplifier, a third resistor coupled between the first output of the first operational amplifier and the first input of the second input of the second operational amplifier, a fourth resistor coupled between the second output of the first operational amplifier and the second input of the second operational amplifier, and at least one of 1) a first capacitor coupled between the first input of the first operational amplifier and the first output of the second operational amplifier, and a second capacitor coupled between the secondType: GrantFiled: January 19, 2011Date of Patent: April 2, 2013Assignee: Analog Devices, Inc.Inventors: Hajime Shibata, Richard Schreier
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Publication number: 20120182168Abstract: An active RC resonator includes a first operational amplifier having first and second inputs and first and second outputs, a second operational amplifier having first and second inputs and first and second outputs, a first resistor coupled between the first input of the first operational amplifier and the second output of the second operational amplifier, a second resistor coupled between the second input of the first operational amplifier and the first output of the second operational amplifier, a third resistor coupled between the first output of the first operational amplifier and the first input of the second input of the second operational amplifier, a fourth resistor coupled between the second output of the first operational amplifier and the second input of the second operational amplifier, and at least one of 1) a first capacitor coupled between the first input of the first operational amplifier and the first output of the second operational amplifier, and a second capacitor coupled between the secondType: ApplicationFiled: January 19, 2011Publication date: July 19, 2012Applicant: Analog Devices, Inc.Inventors: Hajime Shibata, Richard Schreier
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Patent number: 7358879Abstract: A ?? modulator system with start up transient suppression includes a ?? analog to digital converter having predetermined internal signal limits; an envelope control circuit for attenuating the input signal to the ?? analog to digital converter and a control circuit responsive to a start/reset signal to enable for a limited time the envelope control circuit to attenuate the input signal to maintain the ?? analog to digital converter internal signal substantially within the predetermined internal signal limits.Type: GrantFiled: July 26, 2006Date of Patent: April 15, 2008Assignee: Analog Devices, Inc.Inventors: Richard Schreier, Nazmy Abaskharoun
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Patent number: 7342614Abstract: Methods and apparatus for tuning are disclosed. One embodiment of the invention is directed to a tuner formed on a substrate. The tuner comprises a first die that receives an analog input signal and processes the analog input signal using analog processing circuitry to form analog output signals, and a second die that receives the analog output signals, converts the analog output signals to digital signals, and processes the digital signals to form output signals. Another embodiment of the invention is directed to a multi-chip module comprising a tuner adapted to process television signals of a plurality of types and of a plurality of standards to form output signals.Type: GrantFiled: May 20, 2004Date of Patent: March 11, 2008Assignee: Analog Devices, Inc.Inventors: Iuri Mehr, Sergei Nesterenko, Richard Schreier, David Robertson
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Publication number: 20070035429Abstract: A ?? modulator system with start up transient suppression includes a ?? analog to digital converter having predetermined internal signal limits; an envelope control circuit for attenuating the input signal to the ?? analog to digital converter and a control circuit responsive to a start/reset signal to enable for a limited time the envelope control circuit to attenuate the input signal to maintain the ?? analog to digital converter internal signal substantially within the predetermined internal signal limits.Type: ApplicationFiled: July 26, 2006Publication date: February 15, 2007Inventors: Richard Schreier, Nazmy Abaskharoun
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Publication number: 20070035430Abstract: An improved ?? analog to digital converter system with automatic gain control response to out-of-band interferers including a ?? multibit analog to digital converter responsive to an analog input for providing a digital output including the in-band signal and out-of-band interferers and quantization noise and a signal peak estimator circuit responsive to the out-of-band interferers for generating a gain control signal for adjusting the gain of a variable gain element which may be an independent element such as a variable gain amplifier or it may be the analog to digital converter itself by virtue of its having an adjustable full-scale.Type: ApplicationFiled: August 2, 2006Publication date: February 15, 2007Inventors: Richard Schreier, Hassan L'Bahy
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Publication number: 20070035426Abstract: A continuous time ?? modulation system with automatic timing adjustment includes a loop filter having continuous time elements for receiving an input; and an ADC for sampling the output from the loop filter in response to an ADC clock; a DAC responsive to the output from the ADC for feeding back an input to the loop filter in response to a DAC clock; a timing measurement circuit for detecting a difference in the timing of the ADC sampling time and the DAC update time and a timing adjustment circuit responsive to the timing measurement circuit for adjusting the timing of at least one of the DAC and ADC clocks for aligning their respective update and sampling times.Type: ApplicationFiled: May 19, 2006Publication date: February 15, 2007Inventors: Richard Schreier, Donald Paterson
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Publication number: 20070035427Abstract: An improved quadrature bandpass ?? converter includes a loop filter, an ADC responsive to the loop filter, and a first feedback DAC responsive to the ADC; a first summing circuit is responsive to the first DAC and an analog input for providing an input to the loop filter; a second feedback DAC is responsive to the ADC for providing an input to the loop filter; the loop filter includes a plurality of signal resonators, at least one image resonator, a second summing circuit, and a feed forward circuit connecting at least two of the resonators to the second summing circuit for reducing the quantization noise from the ADC; the image resonator is responsive to the second DAC for reducing the image quantization noise.Type: ApplicationFiled: June 1, 2006Publication date: February 15, 2007Inventors: Richard Schreier, Wenhua Yang, Hajime Shibata
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Patent number: 7079063Abstract: A system is disclosed for processing digital signals in a data converter. The system includes a thermometer encoder for receiving signed binary data and for providing signed thermometer data. The signed thermometer data includes positive thermometer data and negative thermometer data. The system also includes a shuffler that receives positive input data responsive to the positive thermometer data and receives negative input data responsive to the negative thermometer data. The system also includes a decoder for receiving output data from the shuffler and providing decoded data to an analog output stage.Type: GrantFiled: April 18, 2005Date of Patent: July 18, 2006Assignee: Analog Devices, Inc.Inventors: Khiem Quang Nguyen, Richard Schreier
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Publication number: 20050259186Abstract: Methods and apparatus for tuning are disclosed. One embodiment of the invention is directed to a tuner formed on a substrate. The tuner comprises a first die that receives an analog input signal and processes the analog input signal using analog processing circuitry to form analog output signals, and a second die that receives the analog output signals, converts the analog output signals to digital signals, and processes the digital signals to form output signals. Another embodiment of the invention is directed to a multi-chip module comprising a tuner adapted to process television signals of a plurality of types and of a plurality of standards to form output signals.Type: ApplicationFiled: May 20, 2004Publication date: November 24, 2005Applicant: Analog Devices, Inc.Inventors: Iuri Mehr, Sergei Nesterenko, Richard Schreier, David Robertson
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Patent number: 6737999Abstract: Mismatch-shaping for a digital-to-analog converter (DAC) involves allocating elements from an element array to multiple DAC channels. Various state variables are used to keep track of element usage, and the number of state variables is preferably less than the number of elements in the element array. The element array may be treated like a bi-directional circular array, in which case the array elements may be allocated to the two DAC channels as needed in opposite directions with reference to a common anchor point such that the array elements for each channel are contiguous within the circular array. All array elements are available for allocation to both DAC channels, although no array element can be allocated to both DAC channels simultaneously. A collision resolution scheme is used to prevent overlapping allocations of array elements. Pointers may be used to keep track of the array elements allocated to each channel, making implementation relatively simple.Type: GrantFiled: September 3, 2002Date of Patent: May 18, 2004Assignee: Analog Devices, Inc.Inventor: Richard Schreier
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Publication number: 20040041719Abstract: Mismatch-shaping for a digital-to-analog converter (DAC) involves allocating elements from an element array to multiple DAC channels. Various state variables are used to keep track of element usage, and the number of state variables is preferably less than the number of elements in the element array. The element array may be treated like a bi-directional circular array, in which case the array elements may be allocated to the two DAC channels as needed in opposite directions with reference to a common anchor point such that the array elements for each channel are contiguous within the circular array. All array elements are available for allocation to both DAC channels, although no array element can be allocated to both DAC channels simultaneously. A collision resolution scheme is used to prevent overlapping allocations of array elements. Pointers may be used to keep track of the array elements allocated to each channel, making implementation relatively simple.Type: ApplicationFiled: September 3, 2002Publication date: March 4, 2004Inventor: Richard Schreier
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Patent number: 6567025Abstract: A multi-bit sigma-delta analog to digital converter has a quantizer, a loop filter circuit, and a digital to analog feedback circuit. The quantizer, loop filter, and digital to analog feedback circuit have a loop gain associated therewith. The quantizer and loop filter have a combined gain associated therewith. The full-scale of the digital to analog feedback circuit is varied. The combined gain of the quantizer and loop filter is also varied. More specifically, the combined gain of the quantizer and loop filter is varied in inverse proportion to the full-scale of the digital to analog feedback circuit to maintain the loop gain at a substantially constant level.Type: GrantFiled: February 5, 2002Date of Patent: May 20, 2003Assignee: Analog Devices, Inc.Inventors: Richard Schreier, Lawrence Singer, Jennifer A. Lloyd
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Publication number: 20020105449Abstract: A multi-bit sigma-delta analog to digital converter has a quantizer, a loop filter circuit, and a digital to analog feedback circuit. The quantizer, loop filter, and digital to analog feedback circuit have a loop gain associated therewith. The quantizer and loop filter have a combined gain associated therewith. The full-scale of the digital to analog feedback circuit is varied. The combined gain of the quantizer and loop filter is also varied. More specifically, the combined gain of the quantizer and loop filter is varied in inverse proportion to the full-scale of the digital to analog feedback circuit to maintain the loop gain at a substantially constant level.Type: ApplicationFiled: February 5, 2002Publication date: August 8, 2002Inventors: Richard Schreier, Lawrence Singer, Jennifer A. Lloyd