Patents Assigned to Broadcom
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Publication number: 20050093531Abstract: A bandgap voltage generator generates an output reference voltage and is configured to operate from a low voltage power supply and consumes low power. The bandgap voltage generator includes a non-cascode current mirror that is directly connected to a power supply input and that produces current mirror outputs in response to the power supply input. A differential amplifier senses two of the current mirror outputs, and generates an output that controls the non-cascode current mirror so that the current mirror outputs produce substantially the same current and voltage at the sensed current mirror outputs. A bandgap core circuit includes first and second bipolar devices that receive the constant current from the two current mirror outputs. The first bipolar device is scaled in size relative to the second bipolar device so as to produce an output voltage at a third current mirror output that is multiple of the characteristic bandgap voltage of the bipolar devices.Type: ApplicationFiled: June 30, 2004Publication date: May 5, 2005Applicant: Broadcom CorporationInventors: Pieter Vorenkamp, Venugopal Gopinathan
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Patent number: 6887741Abstract: An electrically and thermally enhanced die-up ball grid array (BGA) package is described. An integrated circuit (IC) package includes a first substrate, a second substrate, and a stiffener. A surface of the first substrate is attached to a first surface of the stiffener. A surface of the second substrate is attached to a second surface of the stiffener. An IC die may be attached to a second surface of the second substrate or to the second surface of the stiffener. Additional electronic devices may be attached to the second surface of the second substrate.Type: GrantFiled: December 9, 2003Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Sam Ziqun Zhao, Reza-ur Rahman Khan, Imtiaz Chaudhry
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Patent number: 6888410Abstract: A power amplifier includes an input transistor, an input bias circuit, an output transistor, and a power down circuit. The input transistor includes a gate, a drain, and a source, wherein the source of the input transistor is coupled to a supply voltage return and the gate of the input transistor is operably coupled to receive an outbound radio frequency (RF) signal. The input bias circuit is operably coupled to provide an enabling bias voltage to the gate of the input transistor during transmit mode and to provide a disabling bias voltage to the gate of the input transistor during power down mode. The output transistor includes a gate, a drain, and a source, wherein the drain of the output transistor is coupled to provide an output of the power amplifier and the source of the output transistor is coupled to the drain of the input transistor.Type: GrantFiled: October 10, 2003Date of Patent: May 3, 2005Assignee: Broadcom Corp.Inventor: Qiang (Thomas) Li
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Patent number: 6888562Abstract: A two-way visual communication device and methods for operating such a device are disclosed. An embodiment of the disclosed invention may comprise a visual display device and one or more pinhole imaging devices positioned within the active display area of the visual display. An image processor may be used to analyze the displayed image, and to select the output signal from one of the pinhole imaging devices. The image processor may also modify the displayed image in order to optimize the degree of eye contact as perceived by the far-end party.Type: GrantFiled: March 26, 2003Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Darwin Rambo, Philip Houghton
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Patent number: 6888381Abstract: Various methods and circuits for implementing high speed peak amplitude comparison. The invention achieves higher speed of operation by eliminating the slow feedback loop commonly employed in peak detection. In one embodiment, the invention directly compares a signal that represents the peak amplitude of the input signal minus a small voltage drop, to a modified reference voltage. The modified reference voltage corresponds to the reference voltage that is adjusted to compensate for the small voltage drop in the maximum input voltage. In another embodiment, the invention implements a differential version of the peak amplitude comparator to obtain better noise rejection and reduced effective offset among other advantages.Type: GrantFiled: October 1, 2001Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Afshin Momtaz, Wee-Guan Tan, Armond Hairapetian
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Patent number: 6888578Abstract: A method and system for correcting luma data and chroma data from a composite signal for a plurality of lines are disclosed. The method and system include correlating line data of the composite signal from a portion of the plurality of lines to provide a plurality of correlation signals. The method and system also include generating a chroma suppression signal based on the plurality of correlation signals. The chroma suppression signal indicates whether to suppress a portion of the chroma data. The chroma suppression signal indicates that the portion of the chroma data should be suppressed when a large luma transition and the chroma data being beneath a threshold are detected.Type: GrantFiled: May 13, 2002Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Aleksandr M. Movshovich, Brad A. Delanghe, Darren Neuman
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Patent number: 6888761Abstract: A system-on-chip (SOC) device or a random access memory (RAM) chip includes a RAM block. The RAM block includes memory cells, each of which has three transistors. Each memory cell is coupled to both a read bit line and a write bit line. A transparent continuous refresh mechanism has been implemented to read the content of a memory cell and re-write it back to the memory cell without disturbing the access (read/write) cycle, making refresh operations transparent to the system level. The continuous refresh mechanism includes a collision detection mechanism to prevent writing and reading the same memory cell at the same time.Type: GrantFiled: January 27, 2004Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Cyrus Afghahi, Sami Issa
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Patent number: 6888844Abstract: A method for selecting an operating mode for a frame-based communications network consisting of a plurality of stations attached to a transmission medium. The plurality of stations include both a first type station and a second type station. The first type station is capable of transmitting and receiving first protocol frames in accordance with a first protocol. The second type station is capable of transmitting and receiving both first protocol frames and second protocol frames in accordance with a second protocol. The first protocol and the second protocol each use different signals on the transmission medium. The first type station is not capable of reliably detecting second protocol frames. The first protocol has a first protocol frame format containing at least two reserved bits in a first protocol frame header which are ignored in received frames by first type stations and always sent with a same fixed value by first type stations.Type: GrantFiled: April 4, 2001Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Tracy D. Mallory, John T. Holloway, Henry S. Ptasinski
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Patent number: 6888411Abstract: A multi-stage, variable gain amplifier whose linearity is relatively insensitive to variations in gain control is disclosed. The amplifier includes a primary cascoded pair of transistors for producing a primary output current from an input voltage as a function of a primary cascode control voltage. The amplifier further includes one or more secondary cascoded pairs of transistors coupled to the primary cascoded pair of transistors for producing one or more secondary output currents from the input voltage as a function of one or more secondary cascode control voltages.Type: GrantFiled: June 6, 2003Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Arya Reza Behzad, Li Lin
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Patent number: 6888778Abstract: A decoder providing asynchronous reset, redundancy, or both, an asynchronously-resettable decoder with redundancy. The decoder has a synchronous portion, responsive to a clocked signal; an asynchronous portion coupled with an asynchronous circuit; a feedback-resetting portion, which substantially isolates the synchronous portion from the asynchronous portion coupled with, and interposed between the synchronous portion in response to a asynchronous reset signal; a signal input; a first memory output coupled with a first memory cell group; a second memory output coupled with a second memory cell group; and a selector coupled between the signal input, the first memory output, and the second memory output. This decoder can be memory row-oriented, and thus provide an asynchronously-resettable row decoder with row redundancy, or an asynchronously-resettable column decoder with column redundancy.Type: GrantFiled: February 26, 2004Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Esin Terzioglu, Morteza Cyrus Afghahi
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Patent number: 6888405Abstract: A programable gain amplifier (PGA) has an amplifier and a variable resistor that is connected to the output of the amplifier. The variable resistor includes a resistor that is connected to a reference voltage and multiple parallel taps that tap off the resistor. A two-stage switch network having fine stage switches and coarse stage switches connects the resistor taps to an output node of the PGA. The taps and corresponding fine stage switches are arranged into two or more groups, where each group has n-number of fine stage switches and corresponding taps. One terminal of each fine stage switch is connected to the corresponding resistor tap, and the other terminal is connected to an output terminal for the corresponding group. The coarse stage switches select from among the groups of fine stage switches, and connect to the output of the PGA.Type: GrantFiled: February 26, 2003Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventors: Felix Cheung, Kevin T. Chan, Siavash Fallahi
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Patent number: 6888483Abstract: An input stage includes a plurality of arrays of autozero amplifiers arranged in series in each array, wherein each autozero amplifier receives an output of a preceding autozero amplifier, wherein a first autozero amplifier in each array amplifiers receives an input signal and a corresponding reference voltage at its inputs, and wherein at least one of the autozero amplifiers includes a circuit that receives the signal corresponding to the output signal, the circuit substantially passing the signal corresponding to the output signal and the reference voltages to the amplifiers during the clock phase ?2 and substantially rejecting the signal corresponding to the output signal during the clock phase ?1.Type: GrantFiled: July 20, 2004Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventor: Jan Mulder
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Patent number: 6889037Abstract: A mixer is disclosed that includes first and second transconductance modules that, in one embodiment, includes MOSFETs configured to receive a plurality of signals that are to be mixed and a selectively coupled auxiliary current source to inject an auxiliary current into the second transconductance module approximately at or near a zero-crossing point in order to reduce flicker noise and other noise introduced into an output signal during switching. Accordingly, as a first transconductance module approaches a zero-crossing, auxiliary current is injected to reduce the current produced therefrom thereby reducing flicker noise. In a differential mixer, the amount of current produced from a transistor pair to which the signal cycle is being switched is also reduced thereby reducing noise from the transistor pair that is turning on for the next portion of a signal cycle.Type: GrantFiled: August 20, 2002Date of Patent: May 3, 2005Assignee: Broadcom CorporationInventor: Hooman Darabl
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Publication number: 20050091048Abstract: A method for performing packet loss concealment (PLC) and/or frame erasure concealment (FEC) in a speech decoder of a voice communication system. In accordance with the method, if a segment of an encoded speech signal is determined to be bad, an excitation signal is derived by scaling a random sequence of samples, and long-term and short-term predictive parameters are derived based on parameters associated with a previously-decoded segment. The excitation signal is then filtered by a long-term synthesis filter and a short-term synthesis filter under the control of the respective long-term and short-term predictive parameters. If the number of consecutively-received bad segments exceeds a predetermined threshold, the decoded speech signal is gradually reduced.Type: ApplicationFiled: October 20, 2004Publication date: April 28, 2005Applicant: Broadcom CorporationInventors: Jes Thyssen, Juin-Hwey Chen
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Publication number: 20050091046Abstract: A method for adaptive long-term filtering of an audio signal, such as a decoded speech signal. The method includes measuring a smoothed periodicity of an audio signal segment, such as an audio frame, wherein the smoothed periodicity is measured by low-pass filtering an instantaneous periodicity of the audio signal segment. The periodicity of the audio signal segment is then increased in a manner that depends upon whether the smoothed periodicity is less than a predetermined threshold. By utilizing a smoothed periodicity measurement in this fashion, more accurate control of the post-filter is provided as compared to conventional solutions. Additionally, the method includes deriving filters by interpolating between filter responses of adjacent audio signal segments to minimize distortion at segment boundaries.Type: ApplicationFiled: October 20, 2004Publication date: April 28, 2005Applicant: Broadcom CorporationInventors: Jes Thyssen, Juin-Hwey Chen
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Patent number: 6885988Abstract: A method of concealing bit errors in a signal is provided. The method comprises encoding a signal parameter according to a set of constraints placed on a signal parameter quantizer. The encoded signal parameter is decoded and compared against the set of constraints. Finally, the method includes declaring the decoded signal parameter invalid when the set of constraints is violated. Training binned ranges of gain values provide a threshold for selecting data segments to examine for violation of constraints on gain differences. Further, an additional method comprises training a threshold function T(qlg(m?1), ?qlg(m?1) used in a codec bit error detecting technique. The threshold function is based upon a first training file having N signal segments. The method includes encoding the first training file and determining gain values qlg(m) of each of the N signal segments within the encoded first training file. The gain values form a range and the range is divided into bins.Type: GrantFiled: August 19, 2002Date of Patent: April 26, 2005Assignee: Broadcom CorporationInventor: Juin-Hwey Chen
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Patent number: 6885236Abstract: A reference ladder is configured to have improved feedback stability. The reference ladder includes a resistor ladder having a plurality of taps that produce a plurality of reference voltages. The resistor ladder is driven by a first current source at a first tap of the plurality of taps and by a second current source at a second tap of the plurality of taps. A first feedback network senses a voltage at the first tap and controls the first current source based on the first sensed voltage. A second feedback network senses a voltage at the second tap and controls the second current source based on the second sensed voltage. The first and second taps each operate as both a force tap and a sense tap of the resistor ladder. Differential input stages that are connected to the plurality of taps are at least partially isolated from the feedback networks by converging the force and sense taps, thereby improving the stability of the feedback networks.Type: GrantFiled: October 30, 2002Date of Patent: April 26, 2005Assignee: Broadcom CorporationInventor: Pieter Vorenkamp
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Patent number: 6885657Abstract: The present invention includes a network telephone having a microphone coupled to provide voice data to a network, a speaker coupled to facilitate listening to voice data from the network, a dialing device coupled to facilitate routing of voice data upon the network, a first port configured to facilitate communication with a first network device, a second port configured to facilitate communication with a second network device and a prioritization circuit coupled to apply prioritization to voice data provided by the microphone.Type: GrantFiled: November 30, 1999Date of Patent: April 26, 2005Assignee: Broadcom CorporationInventors: Ted F. Rabenko, Ian Crayford, David L. Hartman, Jr.
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Patent number: 6885859Abstract: A process of controlling and monitoring a wireless hotspot by a wireless service provider is disclosed. Data is received from an access point of a wireless hotspot for wireless portable devices and is translated into wireless network data having a format intelligible by a wireless service provider. The wireless network data is sent to the wireless service provider and wireless service provider data is received from the wireless service provider. The wireless service provider data is translated into access point data having a format intelligible by the access point and the access point data is forwarded to the access point.Type: GrantFiled: December 9, 2002Date of Patent: April 26, 2005Assignee: Broadcom CorporationInventors: Jeyhan Karaoguz, Nambi Seshadri
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Patent number: 6885275Abstract: An integrated circuit inductor includes a spiral pattern disposed upon a substrate. The track of the spiral is divided into multiple tracks to form a multi-track inductor. The individual tracks are disposed side by side and in different layers. Tracks that are aligned vertically are coupled by feed throughs, or vias. Multiple vias are used along the length of each of the multiple tracks. Tracks disposed in the same layer are joined together at their beginning, and at their termination. A patterned shield is fabricated from conductive fingers of n+ salicided material that is separated by non conducting polysilicon that fills the gaps between the fingers. The conductive fingers are coupled together in groups, which are in turn tied to a single point ground. In tying the groups together, a gap in the conducting path is provided to prevent ground loop currents. The shield is disposed between the multi-track inductor and the substrate.Type: GrantFiled: January 28, 2000Date of Patent: April 26, 2005Assignee: Broadcom CorporationInventor: James Y. C. Chang