Patents by Inventor Zhaohui He

Zhaohui He has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170271996
    Abstract: A method may include controlling switches of a switching full-bridge of a signal processing system to commutate polarity of a capacitor with respect to the first processing path output and a second processing path output of the signal processing system in response to a condition for commutating connectivity of the switching full-bridge and inserting a feedforward compensation that bypasses a loop filter of the second processing path in order to prevent discontinuities caused by commutating polarity of the capacitor from being compensated by the loop filter.
    Type: Application
    Filed: September 30, 2016
    Publication date: September 21, 2017
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Eric J. KING, Zhaohui HE, Siddharth MARU, John L. MELANSON
  • Publication number: 20170207759
    Abstract: A switching power stage for producing a load voltage may include a first processing path having a first output, a second processing path having a second output, a first plurality of switches comprising at least a first switch coupled between the first output and a first load terminal and a second switch coupled between the first output and the second load terminal, a second plurality of switches comprising at least a third switch coupled between the second output and the first load terminal and a fourth switch coupled between the second output and the second load terminal, and a controller configured to control switches in order to generate the load voltage as a function of an input signal such that one of the first switch and the second switch operates in a linear region of operation and one of the third switch and the fourth switch operates in a saturated region of operation for a predominance of a dynamic rage of the load voltage.
    Type: Application
    Filed: September 20, 2016
    Publication date: July 20, 2017
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Zhaohui HE, Eric J. KING, Siddharth MARU, John L. MELANSON
  • Publication number: 20170207755
    Abstract: A switching power stage for producing a load voltage at a load output of the switching power stage, wherein the load output comprises a first load terminal having a first load voltage and a second load terminal having a second load voltage such that the load voltage comprises a difference between the first and the second load voltages, that may include: a power converter comprising a power inductor and a plurality of switches, wherein the power converter is configured to drive a power converter output terminal; a linear amplifier configured to drive a linear amplifier output terminal; and a controller for controlling the plurality of switches and the linear amplifier in order to generate the load voltage as a function of an input signal to the controller such that energy delivered to the load output is supplied predominantly by the power converter.
    Type: Application
    Filed: May 31, 2016
    Publication date: July 20, 2017
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Zhaohui HE, Eric J. KING, Siddharth MARU, John L. MELANSON
  • Patent number: 9577538
    Abstract: A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: February 21, 2017
    Assignee: Koninklijke Philips N.V.
    Inventors: Yanhui Xie, Michael A. Kost, John L. Melanson, Zhaohui He, Chris M. Franklin
  • Patent number: 9520794
    Abstract: An electronic system and method include a controller to operate in a start-up mode to accelerate driving a load to an operating voltage and then operates in a post-start-up mode. A start-up condition occurs when the controller detects that a load voltage is below a predetermined voltage threshold level. The predetermined voltage threshold level is set so that the controller will boost the voltage to an operating value of a load voltage at a faster rate than during normal, steady-state operation. The controller causes a switching power converter to provide charge to the load at a rate in accordance with a start-up mode until reaching an energy-indicating threshold. When the energy-indicating threshold has been reached, the controller causes the switching power converter to (i) decrease the amount of charge provided to the load relative to the charge provided during the start-up mode and (ii) operate in a distinct post-start-up-mode.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: December 13, 2016
    Assignee: PHILIPS LIGHTING HOLDING B.V
    Inventors: Siddharth Maru, Zhaohui He, Mohit Sood, Prashanth Drakshapalli, Rahul Singh
  • Patent number: 9515485
    Abstract: A power control system provides immunity from power supply dropout for a controller without compromising a startup time of the controller. In at least one embodiment, the power control system includes separate startup and dropout immunity capacitors. In at least one embodiment, selection of the capacitance of the startup capacitor is independent of selection of the capacitance of the dropout immunity capacitance. In at least one embodiment, the startup capacitance can be minimized to provide sufficient energy for the controller to normally operate during one missed cycle of an input voltage and, thus, provide a minimum startup time for the controller. The capacitance of the dropout immunity capacitor can be maximized to provide sufficient energy for the controller to operate normally during a time period longer than one cycle of the input voltage.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: December 6, 2016
    Assignee: PHILIPS LIGHTING HOLDING B.V.
    Inventors: William A. Draper, John L. Melanson, Zhaohui He
  • Patent number: 9502984
    Abstract: An electronic system includes a controller to provide at least dual-mode conduction control of a switching power converter. In at least one embodiment, the controller is capable to control transitions between discontinuous conduction mode (DCM) and critical conduction mode (CRM) of the switching power converter using a measured switching time parameter having a value corresponding with an approximately peak voltage of a time-varying supply voltage supplied to the switching power converter. In at least one embodiment, the controller dynamically compensates for changing parameters of the electronic system by dynamically determining a minimum non-conductive time of the control switch of the switching power converter using the measured switching time parameter value at approximately the peak of the supply voltage of the supply voltage.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: November 22, 2016
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventors: John L. Melanson, Zhaohui He
  • Patent number: 9351356
    Abstract: An electronic system includes controller to control a switching power converter to provide power to a load. To control the amount of power provided to the load, in at least one embodiment, the controller senses a current value representing a current in the switching power converter and detects when the current value reaches a target peak value. However, due to delays in the controller and/or the switching power converter, the detected target peak value will not be the actual current peak value generated by the switching power converter. In at least one embodiment, the controller adjusts the detected target peak value with a post-detection delay compensation factor to generate a delay compensated current value that more accurately represents an actual peak current value associated with the current in the switching power converter.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: May 24, 2016
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventors: Zhaohui He, Robert T. Grisamore, Michael A. Kost
  • Patent number: 9313840
    Abstract: A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the controller determines the one or more switching power converter control parameters using a resonant period factor from a reflected secondary-side voltage and an occurrence of an approximate zero voltage crossing of the secondary-side voltage during a resonant period of the secondary-side voltage. In at least one embodiment, the switching power converter control parameters include (i) an estimated time of a minimum value of the secondary-side voltage during the resonant period and (ii) an estimated time at which a current in the secondary-side of the transformer decayed to approximately zero.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: April 12, 2016
    Assignee: Cirrus Logic, Inc.
    Inventors: Robert T. Grisamore, Zhaohui He
  • Patent number: 9307601
    Abstract: An electronic lighting system and method described herein control energy provided to an electronic lighting device, such as one or more light-emitting diodes (LEDs) and/or compact fluorescent lamps (CFLs), of the electronic lighting system. A triac-based dimmer phase cuts a line voltage provided to the electronic lighting system. A controller of the electronic lighting system utilizes a probing system to overcome idiosyncrasies of the triac-based dimmer to allow the controller to probe and sense the line voltage. To reduce energy consumption, rather than probing each cycle of the output voltage of the triac-based dimmer, the controller periodically or intermittently probes the output voltage of the triac-based dimmer.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: April 5, 2016
    Assignee: Koninklijke Philips N.V.
    Inventors: Zhaohui He, Rahul Singh, Eric J. King, John L. Melanson, William A. Draper
  • Publication number: 20150351178
    Abstract: In at least one embodiment, an electronic system adapts current control timing for half line cycle of a phase-cut input voltage and responsively controls a dimmer current in a power converter system. The adaptive current control time and responsive current control provides, for example, interfacing with a dimmer. The electronic system and method include a dimmer, a switching power converter, and a controller to control the switching power converter and controls a dimmer current. In at least one embodiment, the controller determines a predicted time period from a zero crossing until a leading edge of a phase-cut input voltage and then responsively controls the dimmer current to, for example, reduce current and voltage perturbations (referred to as “ringing”), improve efficiency, and reduce an average amount of power handled by various circuit components.
    Type: Application
    Filed: June 2, 2015
    Publication date: December 3, 2015
    Applicant: Cirrus Logic, Inc.
    Inventor: Zhaohui He
  • Publication number: 20150340955
    Abstract: An electronic system includes a controller to provide at least dual-mode conduction control of a switching power converter. In at least one embodiment, the controller is capable to control transitions between discontinuous conduction mode (DCM) and critical conduction mode (CRM) of the switching power converter using a measured switching time parameter having a value corresponding with an approximately peak voltage of a time-varying supply voltage supplied to the switching power converter. In at least one embodiment, the controller dynamically compensates for changing parameters of the electronic system by dynamically determining a minimum non-conductive time of the control switch of the switching power converter using the measured switching time parameter value at approximately the peak of the supply voltage of the supply voltage.
    Type: Application
    Filed: May 1, 2015
    Publication date: November 26, 2015
    Applicant: CIRRUS LOGIC, INC.
    Inventors: John L. Melanson, Zhaohui He
  • Publication number: 20150340956
    Abstract: A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load.
    Type: Application
    Filed: May 1, 2015
    Publication date: November 26, 2015
    Applicant: Cirrus Logic, Inc.
    Inventors: Yanhui Xie, Michael A. Kost, John L. Melanson, Zhaohui He, Chris M. Franklin
  • Patent number: 9184666
    Abstract: A system and method include a controller that reduces power dissipated by a switch, such as a source-controlled field effect transistor, when an estimated amount of power dissipated by the switch exceeds a predetermined threshold. Reducing the power dissipated by the switch prevents damage to the switch due to overheating. The controller determines the estimated amount of power dissipated by the switch using actual drain-to-source current and drain voltage data. In at least one embodiment, the controller includes a fail-safe, estimated power dissipation determination path that activates when the drain voltage data fails a reliability test. Additionally, in at least one embodiment, the controller includes a model of thermal characteristics of the switch. In at least one embodiment, the controller utilizes real-time estimated power dissipation by the switch and the model to determine when the estimated power dissipated by the switch exceeds a power dissipation protection threshold.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: November 10, 2015
    Inventors: Mohit Sood, Spencer Isaacson, Rahul Singh, Zhaohui He
  • Patent number: 9178415
    Abstract: A power control system includes a switching power converter and a controller. The controller is configured to detect an over-current condition of an inductor current in the switching power converter using at least one non-inductor-current signal. In at least one embodiment, the switching power converter does not have a resistor or resistor network to sense the inductor current. In at least one embodiment, the controller indirectly determines a state of the inductor current using at least one non-inductor-current signal. Potentially damaging inductor current values that are, for example, greater than a normal maximum value or at a value that causes a discontinuous conduction mode system to operate in continuous conduction mode represent exemplary inductor over-current conditions addressed by one embodiment of the power control system.
    Type: Grant
    Filed: March 31, 2010
    Date of Patent: November 3, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Michael A. Kost, John L. Melanson, Rahul Singh, Mohit Sood, Zhaohui He
  • Patent number: 9178444
    Abstract: In at least one embodiment, an electronic system and method includes a controller to control a switching power converter in at least two different modes of operation depending on whether the controller detects a dimmer or not and/or whether a load requests more power than either of the two operational modes can provide. In at least one embodiment, the controller detects whether a dimmer is phase cutting an input voltage to a switching power converter. The controller operates the switching power converter in a first mode if the dimmer is detected, and the controller operates the switching power converter in a second mode if the dimmer is not detected. The controller also transitions between operating the switching power converter in the first mode and the second mode if a status of detection of the dimmer changes.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: November 3, 2015
    Inventors: Siddharth Maru, Zhaohui He, Mohit Sood
  • Patent number: 9166485
    Abstract: An electronic system and method includes a controller to control a switching power converter in at least two different modes of operation, a normal mode and an error reduction mode. The controller controls an amount of charge pushed (i.e. delivered) by the switching power converter to a load to reduce a charge quantization error. The charge quantization error represents an amount of charge pushed to the load beyond a target charge amount. The controller determines an amount of charge to be pushed to the load. Based on the amount of charge to be pushed to the load, the controller generates a current control signal that controls a current control switch in the switching power converter. Determination of the control signal depends on whether the controller is operating in normal mode or error reduction mode. The controller attempts to reduce the charge quantization error to avoid power fluctuations.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: October 20, 2015
    Inventors: Siddharth Maru, Zhaohui He
  • Patent number: 9071144
    Abstract: In at least one embodiment, an electronic system adapts current control timing for half line cycle of a phase-cut input voltage and responsively controls a dimmer current in a power converter system. The adaptive current control time and responsive current control provides, for example, interfacing with a dimmer. The electronic system and method include a dimmer, a switching power converter, and a controller to control the switching power converter and controls a dimmer current. In at least one embodiment, the controller determines a predicted time period from a zero crossing until a leading edge of a phase-cut input voltage and then responsively controls the dimmer current to, for example, reduce current and voltage perturbations (referred to as “ringing”), improve efficiency, and reduce an average amount of power handled by various circuit components.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: June 30, 2015
    Assignee: Cirrus Logic, Inc.
    Inventor: Zhaohui He
  • Patent number: 9025347
    Abstract: An electronic system includes a controller to provide at least dual-mode conduction control of a switching power converter. In at least one embodiment, the controller is capable to control transitions between discontinuous conduction mode (DCM) and critical conduction mode (CRM) of the switching power converter using a measured switching time parameter having a value corresponding with an approximately peak voltage of a time-varying supply voltage supplied to the switching power converter. In at least one embodiment, the controller dynamically compensates for changing parameters of the electronic system by dynamically determining a minimum non-conductive time of the control switch of the switching power converter using the measured switching time parameter value at approximately the peak of the supply voltage of the supply voltage.
    Type: Grant
    Filed: December 16, 2011
    Date of Patent: May 5, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: John L. Melanson, Zhaohui He
  • Patent number: 9024541
    Abstract: A power distribution system includes controller of a switching power converter to control the switching power converter and determine one or more switching power converter control parameters. In at least one embodiment, the switching power converter utilizes a transformer to transfer energy from a primary-side of the transformer to a secondary-side of the transformer. In at least one embodiment, the switching power converter control parameters includes a secondary-side conduction time delay that represents a time delay between when the primary-side ceases conducting a primary-side current and the secondary-side begins to conduct a secondary-side current. In at least one embodiment, determining and accounting for this secondary-side conduction time delay increases the prediction accuracy of the secondary-side current value and accurate delivery of energy to a load when the controller does not directly sense the secondary-side current provided to the load.
    Type: Grant
    Filed: March 7, 2014
    Date of Patent: May 5, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Yanhui Xie, Michael A. Kost, John L. Melanson, Zhaohui He, Chris M. Franklin