Patents Assigned to Fairchild Semiconductor Corporation
  • Switching techniques to reduce current overshoot in a DC to DC converter
    Patent number: 9312746
    Abstract: A DC/DC converter system includes gate control circuitry, a transformer, a second stage, and soft start control circuitry. The gate control circuitry is configured to generate a first and a second gate control signal configured to open and close first and second switches of an inverter circuitry, respectively, to generate an AC signal from a DC input signal. The transformer transforms the AC signal and the second stage rectifies the AC signal to a DC output signal. The soft start control circuitry generates a signal to delay a closing of the first switch during an initial portion (Td) of a first cycle of the first switch. A method of soft-starting a DC/DC converter includes generating first and second gate control signals and delaying closing of the first switch during Td.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: April 12, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Hangseok Choi
  • Method and apparatus for electrostatic discharge protection
    Patent number: 9312255
    Abstract: This application discusses, among other things, apparatus and methods for electrostatic discharge (ESD) protection. In an example, an ESD protection circuit can include an ESD control circuit, and a driver-off circuit, wherein the ESD control circuit is configured to send an enable signal to the driver-off circuit and to perform electrostatic discharge to a ground node when detecting occurrence of electrostatic charges, and wherein the driver-off circuit is configured to disable a driving device upon reception of the enable signal.
    Type: Grant
    Filed: April 25, 2013
    Date of Patent: April 12, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventor: Guangchun Tian
  • Trench-based power semiconductor devices with increased breakdown voltage characteristics
    Patent number: 9293526
    Abstract: Exemplary power semiconductor devices with features providing increased breakdown voltage and other benefits are disclosed.
    Type: Grant
    Filed: November 2, 2012
    Date of Patent: March 22, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Joseph A. Yedinak, Ashok Challa, Dean Probst
  • Detection and GSM noise filtering
    Patent number: 9294857
    Abstract: This document discusses, among other things, a GSM noise detection system configured to detect GSM noise at a pole of a four-pole audio jack using first and second comparators. The GSM noise detection system can include first and second comparators configured to compare a value of the pole to respective first and second thresholds and to provide an output indicative of the comparisons and a detection circuit configured to count changes in the output over a first period of time and to detect GSM noise at the pole of the four-pole audio jack using the count.
    Type: Grant
    Filed: August 8, 2012
    Date of Patent: March 22, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Seth M. Prentice
  • Reverse current blocking comparator
    Patent number: 9294080
    Abstract: An apparatus comprises at least one transistor configured as analog switch, a well biasing circuit configured to provide a dynamic electrical bias to a bulk region of the at least one transistor, and a comparator circuit in electrical communication with the well biasing circuit and the transistor. The comparator circuit is configured to detect a first operating condition of the transistor and a second operating condition of the transistor. The well biasing circuit is configured to apply a first electrical bias to the bulk region of a transistor when the first operating condition is detected and apply a second electrical bias to the bulk region of the transistor when the second operating condition is detected, and wherein the comparator is configured to apply hysteresis to detection of the first and second operating conditions.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: March 22, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Tyler Daigle, Julie Lynn Stultz
  • Battery charging system including current observer circuitry to avoid battery voltage overshoot based on battery current draw
    Patent number: 9287731
    Abstract: According to one aspect of the present disclosure, there is provided a battery charging system. The battery charging system includes battery charging circuitry configured to provide charging current to a battery. The battery charging system further includes feedback circuitry configured to generate a feedback signal indicative of a battery charging condition, wherein the battery charging system is configured to control the battery charging current based on, at least in part, the feedback signal. The battery charging system further includes feed forward circuitry configured to adjust the feedback signal to decrease battery charging current when a decrease in battery current draw exceeds a threshold, and wherein the feed forward circuitry is configured to decrease the battery charging current faster than the feedback circuitry.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: March 15, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Rendon Holloway, Qinghung (Michelle) Lee, Jonathan Klein
  • Method and system that determines the value of a resistor in linear and non-linear resistor sets
    Patent number: 9279840
    Abstract: The present subject matter refers to apparatus and methods for identifying a resistance level of a resistor. In an example, circuit configured to identify a resistor can include a plurality of current sources, each current source selectively coupled to the resistor to generate a resistor voltage, a comparator configured to compare the resistor voltage and a reference voltage, and to provide an output indicative of the comparison, and a controller configured to selectively couple a first one or more current sources of the plurality of current sources to the resistor, and to selectively couple a second one or more current sources of the plurality of current sources to the resistor in response to the output indicative of the comparison.
    Type: Grant
    Filed: May 11, 2012
    Date of Patent: March 8, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Hrvoje Jasa, Gregory A. Maher
  • MEMS multi-axis gyroscope Z-axis electrode structure
    Patent number: 9278845
    Abstract: Various examples include microelectromechanical die for sensing motion that includes symmetrical proof-mass electrodes interdigitated with asymmetrical stator electrodes. Some of these examples include electrodes that are curved around an axis orthogonal to the plane in which the electrodes are disposed. An example provides vertical flexures coupling an inner gimbal to a proof-mass in a manner permitting flexure around a horizontal axis.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: March 8, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventor: Cenk Acar
  • Micromachined monolithic 6-axis inertial sensor
    Patent number: 9278846
    Abstract: The device layer of a 6-degrees-of-freedom (6-DOF) inertial measurement system can include a single proof-mass 6-axis inertial sensor formed in an x-y plane, the inertial sensor including: a main proof-mass section suspended about a single, central anchor; a central suspension system configured to suspend the 6-axis inertial sensor from the single, central anchor; and a drive electrode including a moving portion and a stationary portion, the moving portion coupled to the radial portion. The drive electrode and the central suspension system are configured to oscillate the 6-axis inertial sensor about a z-axis normal to the x-y plane.
    Type: Grant
    Filed: September 18, 2011
    Date of Patent: March 8, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Cenk Acar
  • Power switching system with control signal driven supply voltage
    Patent number: 9273626
    Abstract: Generally, this disclosure provides systems and methods for a power switching system with a switching control circuit powered by a supply voltage derived from an input control signal. The system may include a power switch configured to electrically couple a device between a battery voltage and a ground, the device to be powered by the battery when the power switch is closed; a control circuit coupled to a gate port of the power switch, the control circuit configured to open and close the power switch by adjusting a gate driving signal provided to the gate port in response to a switching control signal provided to the control circuit; and a voltage conditioning circuit configured to generate a supply voltage based on the switching control signal, such that the supply voltage powers the control circuit.
    Type: Grant
    Filed: December 26, 2012
    Date of Patent: March 1, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: James E. Gillberg
  • Photovoltaic system power optimization
    Patent number: 9276402
    Abstract: An example system may comprise at least one solar panel including a plurality of photovoltaic cells, wherein the photovoltaic cells are grouped into at least a first group of cells and a second group of cells. The first and second groups of cells may be coupled in series to a DC bus to deliver DC voltage and power to the DC bus. The system may further include first power conversion circuitry configured to generate power from the first group of cells and second power conversion circuitry configured to generate power from the second group of cells, and inverter circuitry coupled to the DC bus and configured to generate AC power from the DC bus. The first power conversion circuitry may be configured to automatically adjust at least one of an output voltage or power delivered to the DC bus based on an operating point of the second power conversion circuitry.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: March 1, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Van Niemela
  • Apparatus related to a diode device including a JFET portion
    Patent number: 9263438
    Abstract: In one general aspect, an apparatus can include an anode terminal, and a cathode terminal. The apparatus can include a junction field-effect transistor (JFET) portion having a channel disposed within a semiconductor substrate and defining a first portion of an electrical path between the anode terminal and the cathode terminal. The apparatus can also include a diode portion formed within the semiconductor substrate and defining a second portion of the electrical path between the anode terminal and the cathode terminal. The diode portion can be serially coupled to the channel of the JFET device.
    Type: Grant
    Filed: March 22, 2012
    Date of Patent: February 16, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Sunglyong Kim, Jongjib Kim
  • Method and apparatus for integrated circuit protection
    Patent number: 9263431
    Abstract: In certain examples an integrated circuit protection circuit can include a circuit module, and an isolation device. The isolation device can be configured to couple a ground node of the circuit module to a power ground in an on state, and to isolate the ground node of the circuit module from the power ground in an off state, wherein the isolation module is configured to enter the off state when the IC receives a negative input voltage.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: February 16, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Sam Zheng, Gary Sun, Steven M. Leibiger, Tyler Daigle, Julie Lynn Stultz
  • Noise-canceling headphone depletion-mode switch
    Patent number: 9253564
    Abstract: This document discusses, among other things, systems and methods including a depletion-mode switch configured to pass an audio signal from an input to an output in a low-impedance state when a power source is below a threshold and to isolate the input from the output in a high-impedance state when the power source is above the threshold and a noise-cancelation circuit configured to receive the audio signal from the input and to provide a modulated audio signal at the output when the power source is above the threshold.
    Type: Grant
    Filed: June 18, 2013
    Date of Patent: February 2, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventor: Seth M. Prentice
  • Micromachined monolithic 3-axis gyroscope with single drive
    Patent number: 9246018
    Abstract: This document discusses, among other things, a cap wafer and a via wafer configured to encapsulate a single proof-mass 3-axis gyroscope formed in an x-y plane of a device layer. The single proof-mass 3-axis gyroscope can include a main proof-mass section suspended about a single, central anchor, the main proof-mass section including a radial portion extending outward towards an edge of the 3-axis gyroscope sensor, a central suspension system configured to suspend the 3-axis gyroscope from the single, central anchor, and a drive electrode including a moving portion and a stationary portion, the moving portion coupled to the radial portion, wherein the drive electrode and the central suspension system are configured to oscillate the 3-axis gyroscope about a z-axis normal to the x-y plane at a drive frequency.
    Type: Grant
    Filed: September 18, 2011
    Date of Patent: January 26, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Cenk Acar
  • Audio amplifier performance while maintaining USB compliance and power down protection
    Patent number: 9246445
    Abstract: An apparatus comprises a first audio amplifier circuit configured to provide an analog audio signal and an analog switch circuit including a first input configured to receive the analog audio signal, a second input configured to receive a first digital data signal, and a first output configured to provide one of the digital data signal or the analog audio signal. The apparatus also includes a first feedback circuit coupled to the first audio amplifier circuit and the analog switch circuit output, the feedback circuit configured to bias the first audio amplifier circuit.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: January 26, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Julie Lynn Stultz, Earl Schreyer
  • Early warning strobe for mitigation of line and load transients
    Patent number: 9235221
    Abstract: This document discusses apparatus and methods associated with an early warning strobe input of a boost converter. In an example, a method of increasing a set point of a boost converter configured to provide power to a mobile device can include receiving an indication that the mobile device will transition from the first low-power mode to a second higher-power mode; and increasing the set point of the boost converter in response to the indication.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: January 12, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Juha Joonas Oikarinen, Juha-Matti Kujala, Jonathan Klein
  • Load switch with true reverse current blocking
    Patent number: 9236375
    Abstract: Devices, systems and methods are provided for switching a load with true reverse current blocking (TRCB). The device may include an input port coupled to a supply voltage; an output port coupled to the load; a TRCB circuit coupled to the input port and the output port; and a switch control port coupled to the TRCB circuit. The TRCB circuit may be configured to couple the input port to the output port in response to a switch close signal applied to the switch control port and to de-couple the input port from the output port in response to a switch open signal applied to the switch control port. The TRCB circuit may further be configured to block current flow from the output port to the input port in response to both the switch open signal and the switch close signal.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: January 12, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Ni Sun
  • Dual input single output power multiplexer for near field communication application
    Patent number: 9236912
    Abstract: Generally, this disclosure provides systems, methods and platforms for power multiplexer switching operations. The system may include a near field communication (NFC) module configured to receive power through a radio frequency (RF) channel; a subscriber identity module (SIM) circuit configured with a supply voltage port; and a power multiplexer circuit configured to controllably couple the SIM circuit supply voltage port to the NFC module, wherein the NFC module provides a supply voltage to the SIM circuit such that the SIM circuit is operable in the absence of primary device power source.
    Type: Grant
    Filed: November 23, 2012
    Date of Patent: January 12, 2016
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Ni Sun, Jeongil Lee, Sam Zheng
  • Successive approximation resistor detection
    Patent number: 9229833
    Abstract: An apparatus comprises a connector configured to receive an electrical contact of an accessory device that is electrically coupled to a resistor of the accessory device, a current source configured to apply a specified current to the resistor to generate a resulting voltage, a comparator configured to receive and compare the resulting voltage to a reference voltage, and a controller configured to store an outcome of the comparison as a bit in a register, to adjust the applied current using the outcome of the comparison, and to determine a resistance value for the resistor using the bit stored in the register.
    Type: Grant
    Filed: January 26, 2012
    Date of Patent: January 5, 2016
    Assignee: FAIRCHILD SEMICONDUCTOR CORPORATION
    Inventors: Randall Wetzel, Kenneth P. Snowdon, Kenneth O'Brien