Patents Represented by Attorney, Agent or Law Firm John W. Branch
  • Patent number: 6826385
    Abstract: A method and system for increasing the number of geographical addresses for mobile devices in regions of the Earth nearer to the equator than those regions closer to the North and South poles and without significantly increasing the size (number of bits) of the addresses is provided. Typically, regions nearer to the equator have higher populations and a greater need for large amounts of geographical addresses than those regions found closer to the South and North poles. By using the sine of a latitude coordinate for a particular location instead of the actual latitude coordinate, the range of available geographical addresses for mobile devices in the most densely populated regions on Earth can be significantly increased while decreasing the number of addresses available in regions closer to the South or North poles.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: November 30, 2004
    Assignee: Nokia Corporation
    Inventor: Jouni Kujala
  • Patent number: 6822600
    Abstract: A method and circuit for terminating a pre-amplification array for stable linearity of a folding or flash analog-digital-converter (ADC) circuit over a temperature range. Termination resistors with pre-selected temperature coefficients are coupled between outputs of a first and a last amplifier of an amplifier bank in an averaged pre-amplification stage and a termination voltage source. The termination resistors and the termination voltage provide a current that compensates temperature dependent changes in the current flowing from other amplifiers outputs towards the output of the first and last amplifiers stabilizing linearity when temperature changes. Multiple termination resistors with different temperature coefficients may be employed to better approximate the desired temperature coefficient for optimum performance.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: November 23, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Robert C. Taft, Christopher A. Menkus
  • Patent number: 6763019
    Abstract: A method and system for fast channel changes of media that is provided by carriers over an xDSL connection to a home. Each customer's subscriber information is stored at the DSLAM that supports the xDSL connection to the home. Also, each DSLAM supports multicast protocols so that only one instance of a channel is provided on the core network regardless of how many customers have requested access to the channel.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: July 13, 2004
    Assignee: Nokia Corporation
    Inventors: Hemang Mehta, Don Camacho, Gabor Fencsik, Greg Bathrick
  • Patent number: 6750638
    Abstract: A linear regulator includes at least two control loops that monitor different control variables of the output signal. The error signal of the first control loop serves as the reference signal for the second control loop. The conversion of one control variable to the other increases phase margin and improves stability of the frequency response. Also, a capacitor can be coupled to the output of the linear regulator to improve small signal and transient response.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: June 15, 2004
    Assignee: National Semiconductor Corporation
    Inventor: Elliot Lawrence Gang
  • Patent number: 6724251
    Abstract: A circuit with low noise and reduced offset that feeds an input of an opamp with a programmable feedback resistor that provides variable gain settings. Input biasing currents are varied using control bits that are also used to adjust the gain. When the input signal is small (gain at higher setting), a minimum bias current is provided to source the input voltage swing. This scheme reduces the noise and offset generated by the lower transconductance of a biasing transistor while maintaining a constant SNR and fixed offset even in the presence of relatively small input swings. Also, when the input signal is large (gain at lower setting), a maximum bias current can be provided to accommodate the relatively large input swing level. Although the overall noise and offset current are increased for large input swings, the overall SNR and offset is maintained for relatively lower input swings.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: April 20, 2004
    Assignee: National Semiconductor Corp.
    Inventors: Ramsin M. Ziazadeh, Jitendra Mohan, Abu-Hena Mostafa Kamal
  • Patent number: 6720592
    Abstract: The present invention is directed to a photogate based pixel cell with an electronic shutter and which provides relatively low lag and high sensitivity for sensing infrared light reflected from objects. Additionally, this invention eliminates the need for a transfer gate in the pixel cell. In one embodiment, the reset and shutter transistors are implemented with PMOS transistors so that the pixel cell can have an increased dynamic range and a relatively high voltage swing. In another embodiment, the actual size of each pixel cell can be further reduced when the reset gate and the electronic shutter are implemented with NMOS transistors. Also, when a P− well is not disposed beneath the photogate, the ability of the pixel cell to sense infrared light is improved. Correlated double sampling can be used to improve the accuracy of the signal read out from the pixel cell.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: April 13, 2004
    Assignee: National Semiconductor Corp.
    Inventors: Willem Johannes Kindt, Philipp Lindorfer
  • Patent number: 6707425
    Abstract: A method and system is directed to aligning a point-to-multipoint access terminal to an access point. The access terminal provides an output signal, including first and second components, to a readout port. Signal strength that is associated with a received signal is encoded in the first component, while the authentication status of the communication link is encoded in the second component. The antenna alignment is adjusted while monitoring the signal strength via the readout port. The antenna is substantially aligned when the signal strength reaches a peak level. In one example, the signal strength is encoded in a DC component of the output signal, while the authentication status is encoded in an AC component of the output signal. The AC component of an AC encoded signal may have a varied amplitude and/or frequency.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: March 16, 2004
    Assignee: Nokia Corporation
    Inventor: Jyrki Tapio Louhi
  • Patent number: 6639778
    Abstract: A shunt regulator circuit and method for protecting the circuit having a plurality of fuses parallely arranged in a bank so that lower rated fuse can be used while improving the control characteristics of activating the fuse elements. The circuit operates in one of two modes, a shunt regulator mode and a fuse activation mode. In the shunt regulator mode, a feedback circuit prevents any fuse that has blown open form loading a feedback signal to the regulator amplifier of the circuit. In fuse activation mode, each fuse is selectively activated so that a large amount of current is caused to flow through the fuse element until it blows open. This continues for each fuse element in the bank until the safety concern has been eliminated.
    Type: Grant
    Filed: July 22, 2002
    Date of Patent: October 28, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Gregory J. Smith
  • Patent number: 6625848
    Abstract: Striking implements that have an improved ability to store and quickly release significant energy during flexure and at the same time have significant vibration damping capability to impart a desired “feel” to the user. A shape memory alloy element is inserted at a specific flex point along the length of the sports or utility striking implement to permit a desired degree of flexure, with an enhanced leverage effect, and to absorb undesired vibrational energy. Typical sports or utility striking implements utilizing the invention include, but are not limited to, golf clubs, hockey sticks, polo clubs, tennis rackets, racket ball rackets, baseball bats, pole vaults, rowing oars, picks, axes, hammers, and the like.
    Type: Grant
    Filed: October 5, 2000
    Date of Patent: September 30, 2003
    Inventor: Terry L. Schneider
  • Patent number: 6624994
    Abstract: A multiple over current protection circuit for regulating current through an analog switch coupled between a power supply and a load. In a first circuit, a comparator monitors a voltage drop across the analog switch. When the voltage drop exceeds a reference voltage, the comparator momentarily activates a first transistor and causes an amplifier to enter a current limiting mode. The activated first transistor causes the analog switch to momentarily turn off. In a second circuit, the comparator activates a second transistor. During the current limiting mode of the amplifier, a constant voltage is maintained at the source of the second transistor and the load side of the analog switch. A current source draws a current through the second transistor. Also, the current flowing through the analog switch tracks the current flowing through the second transistor.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: September 23, 2003
    Assignee: National Semiconductor Corporation
    Inventors: James Charles Schmoock, Jeffrey P. Kotowski
  • Patent number: 6573783
    Abstract: An open loop offset trim system for use with a differential amplifier includes a reference generator, an offset detector and a trim circuit. To reduce offset, the differential amplifier is placed in an open loop configuration, with both input terminals connected to receive a common reference signal from the reference generator. In response to an offset, the differential amplifier's output signal will essentially rail to either the supply voltage or the ground. In response to the logic level of the differential amplifier's output signal, the offset detector provides a control signal to the trim circuit to adjust the current conducted by one leg of the differential pair to reduce current mismatch in the legs of the differential pair. This process may be performed iteratively to control the trim circuit to incrementally adjust the current conducted by a leg of the differential pair during the trimming process.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: June 3, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Jeromy R. Gray
  • Patent number: 6563322
    Abstract: The present invention relates to an apparatus and a method for detecting an open circuit fault condition in a differential signal, and generating a fault detection signal. An open circuit fault condition is detected by employing weak current sources to pull the differential signal paths outside the valid ac common-mode range and toward the supply rails. If both signal paths can be pulled within a predetermined proximity to the supply rails by their respective weak current sources, an open condition fault is defined to exist and a fault detection signal is generated. The fault detection signal can be used by another device to report the fault condition.
    Type: Grant
    Filed: August 22, 2001
    Date of Patent: May 13, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Douglas Michael Hannan
  • Patent number: 6518847
    Abstract: A method and apparatus is directed to generating an oscillation frequency utilizing the thermal heat transfer properties of semiconductor material as a feedback loop in an oscillator. The oscillator includes a comparator that compares two input signals and enables one of two heater circuits. Each heater circuit is thermally coupled to a sensor and reference circuit. Each sensor and reference circuit pair is arranged such that the reference circuit is heated while the sensor cools. The combination of each sensor and reference circuit produces input signals for the comparator. The frequency of the oscillator is determined by the heat transfer rate between the heater circuit and the corresponding sensor, and the thermal cooling rate of the other sensor. Changing the biasing currents, and distances between the heat sources and the thermal sensors adjust the duty cycle and frequency.
    Type: Grant
    Filed: June 12, 2001
    Date of Patent: February 11, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Don R. Sauer
  • Patent number: 6496345
    Abstract: A circuit for regulating current is disclosed. The circuit includes a current sensor, a controller, and a current limiter. The current sensor is formed from resistance inherent to the current limiter. The controller receives a signal from the current sensor and sends a control signal to the current limiter. The current limiter responds to the control signal by limiting current, if necessary, through the circuit.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: December 17, 2002
    Assignee: National Semiconductor Corporation
    Inventor: Gregory J. Smith
  • Patent number: 6489640
    Abstract: An integrated circuit is provided that has a fuse element incorporated in the circuit. The circuit includes a substrate, a layer of metal disposed on the substrate, a plurality of openings formed through the layer of metal wherein the plurality of openings encircle a region of the layer of metal, and a contact pad coupled to the region of the layer of metal wherein the region of the layer of metal and the contact pad form the fuse element. The fuse element has a low resistance and has the advantage that the fuse element isolates multiple nodes within the integrated circuit from an external contact pad without disrupting the connectivity of the internal nodes to each other.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: December 3, 2002
    Assignee: National Semiconductor Corporation
    Inventor: Gregory J. Smith
  • Patent number: 6473802
    Abstract: A method and system for inserting and examining Cookies in the data streams of HTTP connections for the purpose of persistently directing HTTP connections to the same destination. The invention enables a network device to direct subsequent HTTP connections from the same client to the same server (destination) for accessing the requested resources. There are four modes for employing the Cookie to persistently direct HTTP connections. The associative mode inserts a Cookie that uniquely identifies the client into an HTTP response. The passive mode inserts Cookie information that uniquely identifies a previously selected destination into an HTTP response. In the rewrite mode, a network device manages the destination information that is rewritten over blank Cookie information generated by the destination producing the HTTP response. The insert mode inserts and removes Cookie information in the data packets for HTTP requests and responses prior to processing by the destination.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: October 29, 2002
    Assignee: F5 Networks, Inc.
    Inventor: Richard R. Masters
  • Patent number: 6456123
    Abstract: A translation circuit for transferring a differential voltage to a ground referenced voltage includes a differential input circuit, a sample/hold (S/H) circuit, and a compensation circuit. The S/H circuit includes a S/H capacitor, a series capacitor and a switch. The S/H and series capacitors are connected in series between an output line and a source of ground potential (GROUND). The switch shorts the bottom electrode of the S/H capacitor to GROUND when executing a translation operation. The differential input circuit receives the differential voltage and selectively provides the differential voltage across the S/H capacitor so that the top and bottom electrodes of the S/H capacitor have voltages V+ and V−, respectively. Parasitic capacitance tends to add charge to the S/H capacitor during the translation operation. The compensation circuit compensates for parasitic capacitance by removing, ideally, the same amount of charge from the S/H capacitor by the end of the translation operation.
    Type: Grant
    Filed: August 8, 2000
    Date of Patent: September 24, 2002
    Assignee: National Semiconductor Corporation
    Inventors: Dale A. Oakeson, Don R. Sauer
  • Patent number: 6452766
    Abstract: An over-current protection circuit for a power regulation circuit includes a reference generator that provides a reference level that is related to the level of the power source output that is controlled by the power regulation circuit in providing a regulated output. During normal operating conditions, the over-current protection circuit is isolated from the control signal provided to the pass element by other circuitry of the power regulation circuit. When the output current exceeds a predetermined level, the over-current protection circuit alters the control signal to the pass element to reduce the output current to a level below the predetermined value. If the over-current condition is removed, the over-current protection circuit detects this condition and again isolates itself from the control signal.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: September 17, 2002
    Assignee: National Semiconductor Corporation
    Inventor: Scott Douglas Carper
  • Patent number: 6449719
    Abstract: There is disclosed a process for encrypting a data stream to secure the data stream for single viewing and to protect copyrights of the data stream. Specifically, there is disclosed a process for protecting streaming multimedia, entertainment and communications in an Internet type transmission. There is further disclosed a streaming server component operably connected with a streaming server that interacts with a client system to effect the inventive process.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: September 10, 2002
    Assignee: Widevine Technologies, Inc.
    Inventor: Brian Baker
  • Patent number: 6424972
    Abstract: A method and system for compressing and decompressing read only data in records that have a fixed size. A plurality of records are divided into segments having a predetermined size. For each segment, the records are arranged in a table with rows for each record and a column for each field in each record. The width of each column of repeated data is compressed to zero bits and the repeated data is referenced in a header of the segment. The width of each column of integer data is compressed to the minimum number of bits required to represent the largest integer value in the fields of the column. Floating point data in each column is converted to integer data and the width of the each column with converted integer data is set to the minimum width necessary to represent the largest converted integer in each column. The conversion to integer data is calculated for floating point and real numbers with a minimum precision exponent that is stored in the header for the segment.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: July 23, 2002
    Assignee: Microsoft Corporation
    Inventors: Alexander Berger, Amir Netz, Cristian Petculescu