Patents Represented by Attorney Farajami & Farajami LLP
  • Patent number: 8022682
    Abstract: A circuit for minimizing voltage inrush upon startup in a switching power converter having a switching stage including high and low switches connected at a common node, a feedback loop for maintaining a target output voltage, an output capacitor connected between an output node and the ground, an inductor connected between the common node and the output node, and a control circuit having a first error amplifier for providing a first signal based on a comparison of a reference voltage and voltage provided by the feedback loop, the control circuit including a level switch connected between the ground and the common node, the level switch being controlled in accordance with the first signal, wherein a large inrush current flowing into the output capacitor when the circuit is starting up is minimized.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: September 20, 2011
    Assignee: International Rectifier Corporation
    Inventors: Jun Honda, Xiao-chang Cheng
  • Patent number: 7800399
    Abstract: According to one exemplary embodiment, a termination circuit includes a number of drivers configured to receive source data on an input bus and to drive an output bus including a number of output lines. In the termination circuit the output lines are terminated by resistors, where one resistor is coupled between each output line and a common capacitor node. The termination circuit further includes a virtual regulator at the drivers, configured to control a termination voltage at the capacitor node by inputting compensation data into the drivers during idle cycles to achieve a net average 50% duty cycle. The virtual regulator can determine which cycles are idle by detecting an idle code in the source data.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: September 21, 2010
    Assignee: Broadcom Corporation
    Inventor: Reinhard Schumann
  • Patent number: 7593200
    Abstract: A circuit for detecting faults in a converter, the converter including a switching stage having high- and low-side series switches connected together at a switching node and fault circuitry for managing a plurality of fault conditions, an input voltage source being provided at one terminal of the high-side switch. The circuit including a gate driver circuit connected to gate terminals of the high- and low-side switches for providing PWM signals to control the switching stage; a comparator circuit for comparing a voltage at the switching node to the input voltage and providing an output signal, the comparator circuit having output, positive and negative terminals; a capacitor connected to the output terminal of the comparator circuit to generate an AC component of the comparator circuit output signal; and a rectifier circuit connected to the capacitor for rectifying the AC component of the comparator circuit output signal and providing a fault-indicating signal to the gate driver circuit.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: September 22, 2009
    Assignee: International Rectifier Corporation
    Inventors: Wenkai Wu, George Schuellein
  • Patent number: 7592770
    Abstract: A method and system for controlling a current regulator motor control for parking a motor rotor in a predetermined position, wherein a first current command and a first angle command are supplied to a current regulator for a first parking time, to move the rotor to an intermediate position; and a second current command and a second angle command are supplied to the current regulator for a second parking time, to move the rotor to a predetermined position. The current regulator may have a normal voltage output range, and a circuit may be provided for limiting a voltage output of the current regulator to a reduced voltage output range for at least a portion of the parking time. Advantageously the motor is a permanent-magnet synchronous motor with sinusoidal back-EMF.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: September 22, 2009
    Assignee: International Rectifier Corporation
    Inventor: Eddy Ying Yin Ho
  • Patent number: 7589604
    Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: September 15, 2009
    Assignee: Broadcom Corporation
    Inventors: Lukose Ninan, Stephen E. Krafft