Patents Examined by Rajnikant B. Patel
  • Patent number: 7795854
    Abstract: A voltage regulating circuit including an error signal generator, a comparator, a switch unit, a low-pass filter and a modulating unit is provided. The error signal generator respectively receives a reference voltage signal and a feedback signal, and generates an error signal. The comparator respectively receives the error signal and a comparing signal, and generates a pulse width modulation signal. The switch unit regulates an input voltage signal to generate an output voltage signal according the pulse width modulation signal. The low-pass filter filters out the high frequency of the output signal and produces the feedback signal. The modulating unit is coupled to the low-pass filter and the error signal generator for regulating a transient voltage of the output voltage signal.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: September 14, 2010
    Assignee: Inventec corporation
    Inventors: Chun-Hua Xia, Xiao-Ru Wu, Li Zeng, Da-Wei Hu, Shih-Hao Liu
  • Patent number: 7795857
    Abstract: A band gap voltage reference circuit includes a first band gap circuit configured to generate a first band gap voltage potential. A second band gap circuit includes a variable resistance. The second band gap circuit is configured to output a second band gap voltage potential based on a value of the variable resistance. A calibration circuit is configured to adjust the variable resistance of the second band gap circuit based on the first band gap voltage potential and the second band gap voltage potential. The first band gap circuit is shut down in response to the second band gap voltage potential being within a predetermined range of the first band gap voltage potential.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: September 14, 2010
    Assignee: Marvell International Ltd.
    Inventors: Sehat Sutardja, Jiancheng Zhang
  • Patent number: 7791915
    Abstract: The invention concerns an electric converter for fuel cell (P) comprising current inverter means (2), the electric converter comprising a voltage step-down chopper (1) mounted between the fuel cell (P) and the current inverter means (2), wherein, under the action of a command signal applied to the voltage step-down chopper (1): the value of the mean voltage at the input of the current inverter means is lowered to a threshold value (Vs) in the cell electrode activation zone, the value of the mean voltage at the input of the current inverter means (2) is maintained at the voltage value at the cell terminals (Vp) in the cell resistance zone, and the output current of the converter is limited when the output current from the current inverter means (2) reaches a maximum set value (Imax).
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: September 7, 2010
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Daniel Chatroux, Severine Marc, Yvan Lausenaz
  • Patent number: 7791903
    Abstract: A DC-DC flyback converter, includes a three-winding transformer; a primary power circuit having a first MOSFET connected to a first winding of the transformer; a secondary power circuit connected to a second winding of the transformer terminals; and a self-driven circuit connected to a third winding of the transformer. The secondary power circuit includes a synchronous rectifier in the form of a second MOSFET and the self-driven circuit further includes a delay drive circuit, an isolation differential circuit, a negative removal circuit having a third MOSFET and a synchronous rectifier trigger switch-off circuit for switching the synchronous rectifier to an off condition.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: September 7, 2010
    Assignee: Bel Power (Hangzhou) Co., Ltd.
    Inventors: Congfeng Zhang, Hao Zhang, Guichao Hua
  • Patent number: 7786716
    Abstract: A solar cell regulator in a nanosatellite includes a pulse width modulated DC-DC boost converter and a peak power tracking controller for converting solar cell power to bus power for charging of system batteries and powering loads while the controller controls the pulse width modulation operation of the converter for sensing solar cell currents and voltages along a power characteristic curve of the solar cell for peak power tracking, for determining any power data point, including a peak power point, an open circuit voltage point, and a short circuit current point along the power characteristic curve of the solar cell, and for communicating the power data to a satellite processor for monitoring the performance of the solar cell during operational use of the satellite.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: August 31, 2010
    Assignee: The Aerospace Corporation
    Inventors: Edward J. Simburger, Daniel L. Rumsey, Peter J. Carian
  • Patent number: 7787271
    Abstract: A power supply device including a diode bridge, a converter module, and an inrush control module. The diode bridge is configured to rectify an input voltage. The converter module is coupled to the diode bridge and is configured to convert the input voltage into a direct current regulated output voltage. The inrush control module is connected to the diode bridge and is configured to gradually activate a transistor and to limit an inrush current peak value based upon a zero crossing being detected in the input voltage. A method for limiting the inrush current peak value is also disclosed.
    Type: Grant
    Filed: January 8, 2008
    Date of Patent: August 31, 2010
    Assignee: Dell Products, LP
    Inventors: Lucian Popescu, Constantin D. Livescu
  • Patent number: 7786714
    Abstract: In the field of step-down voltage conversion, it is known to regulate an output of a DC-DC converter circuit with both a Pulse Wave Modulation voltage signal or a Pulse Frequency Modulation voltage signal, depending upon a current demand made upon the DC-DC converter circuit. Typically, circuits to generate both voltage signals are provided and selection of the appropriate regulation mode is achieved by means of a pin and decision software controlling the pin. However, the use of the pin and the software is an overhead that is desirably avoided. Consequently, the present invention provides a voltage conversion apparatus comprising a signal analyzer to analyze a load current signal and compare a characteristic of the load current signal to at least one predetermined criterion. Regulation by the PWM signal or the PFM signal is selected in response to the evaluation of the comparison with the at least one criterion.
    Type: Grant
    Filed: April 1, 2005
    Date of Patent: August 31, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Matthew Bacchi, Vincent Teil
  • Patent number: 7787261
    Abstract: A dc-dc converter system comprises a quasi-regulated bus converter and plural regulation stages that regulate the output of the bus converter. The bus converter has at least one controlled rectifier with a parallel uncontrolled rectifier. A control circuit controls the controlled rectifier to cause a normally non-regulated mode of operation through a portion of an operating range of source voltage and a regulated output during another portion. The bus converter may be an isolation stage having primary and secondary transformer winding circuits. For the non-regulated output, each primary winding has a voltage waveform with a fixed duty cycle. The fixed duty cycle causes substantially uninterrupted flow of power during non-regulated operation. Inductors at the bus converter input and in a filter at the output of the bus converter may saturate during non-regulated operation.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: August 31, 2010
    Assignee: SynQor, Inc.
    Inventors: Richard W. Farrington, Martin F. Schlecht
  • Patent number: 7781920
    Abstract: An electrical power-switching circuit controls power to an electronic device. In some embodiments, the circuit consists of only transistors, resistors, and capacitors, making it small, low cost, and functional over a wide range of supply voltages. The circuit may be switched on and off by a momentary-contact switch. The circuit can be constructed so that, except for transistor leakage current, no power is consumed in the off state, and the controlled device can shut off its own power.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: August 24, 2010
    Inventor: Jan Yuki Malá{hacek over (s)}ek
  • Patent number: 7782039
    Abstract: A regulated power supply includes an inverter comprising an upper switch and a lower switch that are connected in series. A control module selectively controls the upper switch and the lower switch in one of a pulse width modulation (PWM) mode and a discrete control mode (DCM), receives a feedback signal from an output of the regulated power supply, and switches between the PWM mode and the DCM based on the feedback signal.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: August 24, 2010
    Assignee: Marvell International Ltd.
    Inventor: Runsheng He
  • Patent number: 7777460
    Abstract: A multi-phase converter has a plurality of switching circuits each controlled by a phase controller and each providing a switched output voltage to an output node of the converter. Each switching circuit sequentially provides a switched output voltage to the output node at which an output voltage of the converter is developed. A clock circuit provides a plurality of out of phase clock signals to determine when each switching circuit provides the switched voltage to the output node. Each switching circuit is connected across a DC bus voltage. A first error amplifier compares a first signal proportional to the output voltage of the converter at the output node with a second signal comprising a first reference voltage and produces a first error signal. A PWM generator compares the first error signal with a third signal comprising a ramp signal from a ramp signal generator circuit and produces a pulse width modulated signal to control the on-times of a switch of the connected switching circuit.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: August 17, 2010
    Assignee: International Rectifier Corporation
    Inventor: George Schuellein
  • Patent number: 7777455
    Abstract: A switching circuit coupled to one or more input sources and having one or more switching elements controlled to produce an output for charging a battery. A first control circuit is responsive to current of the switching circuit for producing a first control signal to drive the switching element so as to control the current. A second control circuit is responsive to voltage at the battery for producing a second control signal to drive the switching element so as to control voltage developed across the battery. A selector circuit is responsive to the first and second control signals for selectively controlling the switching element.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: August 17, 2010
    Assignee: Linear Technology Corporation
    Inventors: Steven Leo Martin, Trevor Wayne Barcelo
  • Patent number: 7773400
    Abstract: A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.
    Type: Grant
    Filed: August 27, 2007
    Date of Patent: August 10, 2010
    Assignee: Fuji Electric Systems Co., Ltd.
    Inventors: Akira Nakamori, Kazunori Oyabe, Manabu Watanabe
  • Patent number: 7772822
    Abstract: A power supply apparatus having a soft start function that enables a startup without any overshoot within an appropriate startup time regardless of whether the load is heavy or light. Even when output direct current voltage Vo has not yet risen upon startup, switch circuit (4) is turned ON within a count time of timer (7), and clamping circuit (5) clamps error signal (Ve) of error amplifier (2), so that an excessive signal is prevented from entering PWM circuit (6), and electric power supplied to load (13) is controlled. Consequently, supply power as the power supply apparatus is limited, and any inrush current can be prevented from being generated. By controlling the count time of timer (7) when this error signal is clamped, it is possible to realize a startup within an appropriate startup time without any overshoot.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: August 10, 2010
    Assignee: Panasonic Corporation
    Inventors: Yoshihito Kawakami, Junji Ishiyama
  • Patent number: 7772809
    Abstract: A low dropout (LDO) regulator for generating an output voltage on an output from an input voltage of an input source. The LDO regulator including a switch module to generate the output voltage. The switch module including at least two parallel connected switches responsive to corresponding switch control signals to regulate a flow of energy from the input source to the output. Each of the switches having an on-state and an off-state. A digital controller to sense the output voltage and in response to generate the switch control signals such that the output voltage is regulated to a predetermined amplitude.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: August 10, 2010
    Assignee: Marvell World Trade Ltd.
    Inventor: Sehat Sutardja
  • Patent number: 7768248
    Abstract: Embodiments of the invention describe a reference current generator circuit having a core circuit that includes a first transistor in a first current path for conduct a first current and a second transistor in a second current path for conduct a second current. The second transistor has a threshold voltage that is different from the threshold voltage of the first transistor by at least 10%. The voltage differential between the first and second transistors generate a voltage across a resistive component coupled in series with the second transistor in the second current path.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: August 3, 2010
    Assignee: Impinj, Inc.
    Inventor: John D. Hyde
  • Patent number: 7768244
    Abstract: An electrical energy generation system comprising: a plurality of photovoltaic generators connected in parallel and connected to a common load via respective DC voltage converters; and a regulator configured to vary the transconductances of said respective voltage converters to maximize the power generated by said current generators; wherein: said generators are also connected to a common input of an additional voltage converter the output of which is connected to said common load; and said regulator is also configured to vary the transconductance of said additional voltage converter to maximize the power generated by said current generators.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: August 3, 2010
    Assignee: Agence Spatiale Europeene
    Inventor: Philippe Alfred Perol
  • Patent number: 7768801
    Abstract: A current resonant DC-DC converter of multi-output type is provided which comprises an output-regulatory MOS-FET 40 connected between a secondary winding 5c of a transformer 5 and a smoothing capacitor 16 in a second rectifying smoother 17, and an output control circuit 41 for controlling the on-off operation of output-regulatory MOS-FET 40 based on voltage VO2 from smoothing capacitor 16 in second rectifying smoother 17. By turning the on-off operation of output-regulatory MOS-FET 40 in synchronization with switching frequency of first or second MOS-FETs 1, 2, an ideal cross regulation among respective DC outputs can be obtained, providing the inexpensive converter with simple circuit alteration capable of producing highly stable DC outputs with high power conversion efficiency, high accuracy and less power conversion loss.
    Type: Grant
    Filed: August 10, 2005
    Date of Patent: August 3, 2010
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Hiroshi Usui, Yukihiro Kaminaga, Syohei Osaka
  • Patent number: 7760525
    Abstract: A regulator for converting energy from an input source to a voltage of an output. The regulator comprising at least two conduction switches to conduct energy from the input source to the output. Each of the conduction switches operated at approximately 50% duty cycle. At least two inductors in communication with the at least two conduction switches, the at least two inductors wound together on a common core and each inductor having a polarity such that DC currents in the inductors cancel each other. The inductors having a coefficient of coupling approximately greater than 0.99. At least two freewheeling switches in communication with the at least two conduction switches to provide a path for current during non-conduction periods. A drive signal generator to generate drive signals for controlling the at least two conduction switches.
    Type: Grant
    Filed: October 24, 2003
    Date of Patent: July 20, 2010
    Assignee: Marvell World Trade Ltd.
    Inventor: Sehat Sutardja
  • Patent number: 7755344
    Abstract: A low-voltage sub-bandgap reference circuit is disclosed. In one embodiment, the low-voltage sub-bandgap voltage reference circuit includes a differential amplifier and a first bipolar transistor with its base and collector coupled to an electrical ground. The reference circuit further includes a second bipolar transistor with base and collector coupled to the electrical ground. The reference circuit further includes a DC bias circuit supplying a predetermined voltage output between a high and low voltage terminal, the high voltage terminal being coupled to both collectors of the first and second bipolar transistors and the low voltage terminal being coupled to both bases of the first and second bipolar transistors.
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: July 13, 2010
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Chen-Hui Hsieh