Patents Assigned to Monolithic Power Systems
  • Patent number: 8270185
    Abstract: In accordance with the teachings described herein, systems and methods are provided for a switching mode power supply. In one example, the switching mode power supply may include a transformer, a switching circuit and a switching control circuit. The transformer receives a DC input voltage on a primary winding and generates a DC output voltage on a secondary winding. The switching circuit, which may include a MOSFET switch, is coupled to the transformer and is configured to switch the transformer on and off. The switching control circuit generates a switching control signal to control the switching circuit in order to regulate the DC output voltage of the transformer.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: September 18, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Jin Hu, Junming Zhang, Yuancheng Ren
  • Patent number: 8269423
    Abstract: Various embodiments of LED drivers and associated methods of are described below. In one embodiment, a method for controlling an LED driver includes receiving a reference voltage, receiving a feedback voltage from said LED driver, receiving said input voltage as a first feed forward voltage and said output voltage as a second feed forward voltage, generating a hysteretic width based on said first feed forward voltage and said second feed forward voltage, and generating a hysteretic band voltage using said hysteretic width and said reference voltage. The method also includes generating a first control signal for controlling said LED driver based on said hysteretic band voltage and said feedback voltage, inverting said first control signal to generate a second control signal for controlling said LED driver, and achieving a generally fixed frequency for said LED driver.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: September 18, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Kaiwei Yao, Naixing Kuang, Edward Deng
  • Patent number: 8268697
    Abstract: A silicon-on-insulator device with a with buried depletion shield layer.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: September 18, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Donald R. Disney
  • Patent number: 8247984
    Abstract: An LED circuit is disclosed. The circuit senses the average current flowing through the LED. The sensed signal is compensated and modulated. The modulated signal is then used to control the ON/OFF state of a switch that supplies power to the LED.
    Type: Grant
    Filed: April 6, 2010
    Date of Patent: August 21, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Lei Du, Yong Huang
  • Patent number: 8238124
    Abstract: Dual-mode AC/DC power converters and associated methods of operation are disclosed herein. In one embodiment, the AC/DC converter includes a primary winding, a switching transistor coupled to the primary winding, the switching transistor configured to carry a drain-source current, and a feedback voltage port configured to carry a feedback voltage. The feedback voltage port is coupled to the switching transistor to switch off the switching transistor when the drain-source current reaches a peak current limit. The peak current limit increases with increasing feedback voltage if and only if the feedback voltage satisfies an ordered relationship with a threshold.
    Type: Grant
    Filed: December 9, 2009
    Date of Patent: August 7, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Huanyu Lu, En Li
  • Patent number: 8238123
    Abstract: A frequency limitation method used in quasi-resonant control of a switching regulator is disclosed. The switching frequency is limited through setting a minimum time limit, such as a minimum switching period or a minimum OFF time. The minimum time limit may be a first time limit or a second time limit. The minimum time limit is changed into another value if the minimum voltage point approaches the minimum time limit point, so as to eliminate the audible noise.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: August 7, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Junming Zhang, Yuanchang Ren, Jin Hu, Huanyu Lu, Yang Shi
  • Patent number: 8222879
    Abstract: A circuit is disclosed that includes a buck voltage regulator electrically coupled to an active current modulator. The active current modulator is operable to detect a negative current in the low-side switch of the buck voltage regulator circuit during a light mode operation. Whenever the negative current is detected, the active negative current modulator causes the low-side switch to stay ON in a linear mode and limits the negative current to a predetermined current level.
    Type: Grant
    Filed: April 19, 2011
    Date of Patent: July 17, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • Patent number: 8207714
    Abstract: A switching regulator integrated circuit (IC) is disclosed that includes a switch circuit that further includes a first switch and a second switch, a mode selector circuit controlled by external circuitry to select between a first mode and a second mode, and a control circuit. In response to a feedback signal from the switch circuit, when the first mode is selected, the control circuit toggles the first switch and the second switch ON and OFF alternately at a fixed first frequency. When a second mode is selected, the control circuit causes the second switch to turn OFF completely and the first switch to switch ON and OFF at a variable second frequency.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: June 26, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Wei Chen
  • Patent number: 8198880
    Abstract: The present invention discloses a control circuit for constant on-time converter and a control method thereof. The proposed constant on-time DC/DC converter stabilizes the system and improves the performance of the load transient response without large equivalent series resistance of the output capacitor.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: June 12, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Qian Ouyang
  • Patent number: 8198679
    Abstract: High voltage NMOS devices with low on resistance and associated methods of making are disclosed herein. In one embodiment, a method for making N typed MOSFET devices includes forming an N-well and a P-well with twin well process, forming field oxide, forming gate comprising an oxide layer and a conducting layer, forming a P-base in the P-well, the P-base being self-aligned to the gate, side diffusing the P-base to contact the N-well, and forming N+ source pickup region and N+ drain pickup region.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: June 12, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Ji-Hyoung Yoo
  • Publication number: 20120104467
    Abstract: According to one embodiment, a self-aligned trench structure junction gate field-effect transistor (JFET) includes a silicon substrate, two or more trenches having a P-type polysilicon gate region near a bottom portion of the trench and an interlayer dielectric layer (ILDL) above the P-type polysilicon gate region, a channel region separating each trench including epitaxial silicon, an N+ source region above the channel region extending between a top of each trench, and a source metal above the N+ source region. In another embodiment, a self-aligned trench structure JFET includes a silicon substrate, two or more trenches having an N-type polysilicon gate region near a bottom portion of the trench and an ILDL above the N-type polysilicon gate region, a channel region separating each trench including epitaxial silicon, a P+ source region above the channel region extending between a top of each trench, and a source metal above the P+ source region.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 3, 2012
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Tiesheng Li, Ognjen Milic, Lei Zhang
  • Patent number: 8169088
    Abstract: For a DC to DC converter circuit integrated on a packaged die, the relative positions of various die pads and power MOSFETs on the die for a small outline integrated circuit package are described.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: May 1, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • Patent number: 8169801
    Abstract: Voltage converters with integrated low power leaker device and associated methods are disclosed herein. In one embodiment, a voltage converter includes a switch configured to convert a first electrical signal into a second electrical signal different than the first electrical signal. The voltage converter also includes a controller operatively coupled to the switch and a leaker device electrically coupled to the controller. The controller is configured to control the on and off gates of the switch, and the leaker device is configured to deliver power to the controller. The leaker device and the switch are formed on a first semiconductor substrate, and the controller is formed on second semiconductor substrate separate from the first semiconductor substrate.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: May 1, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Michael R. Hsing, Ognjen Milic, Tiesheng Li
  • Patent number: 8164218
    Abstract: SIMO power converters and associated methods of control are disclosed herein. In one embodiment, a method of converting a signal input signal into multiple output signals includes supplying power to a plurality of output terminals based on a signal input signal, detecting a voltage at individual output terminals, determining an arithmetic relationship between the detected voltages of the output terminals, and adjusting the power supplied to the plurality of output terminals based at least in part on the determined arithmetic relationship between the detected voltages of the output terminals.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: April 24, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Naixing Kuang, Lei Du, Junming Zhang, Yuancheng Ren
  • Patent number: 8159141
    Abstract: Methods and apparatus for driving discharge lamps are disclosed herein. In one embodiment, a method for driving a discharge lamp includes generating a switching signal to drive a discharge lamp, monitoring a working status of the discharge lamp, and determining whether the discharge lamp is operating abnormally based at least in part on the monitored working status. The method also includes decreasing a duty cycle of the switching signal when the discharge lamp is determined to operate abnormally.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: April 17, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Naixing Kuang, Lei Du, Junming Zhang, Yuancheng Ren
  • Patent number: 8143948
    Abstract: An error amplifier expected to exhibit rail-to-rail operation, high bandwidth, and high slew rate, is described, the error amplifier comprising a first stage to receive an input differential voltage and to provide transconductance gain, an intermediate stage to provide current gain, and an output stage to drive a load.
    Type: Grant
    Filed: February 19, 2010
    Date of Patent: March 27, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Farhood Moraveji
  • Patent number: 8138734
    Abstract: A DC-DC converter includes a switching stage and a control circuit coupled to provide an accurate current limit for peak current mode for the DC-DC converter. The control circuit is operative to provide a peak value of the peak current mode.
    Type: Grant
    Filed: April 6, 2009
    Date of Patent: March 20, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Xiaoyu Xi, Jian Zhou
  • Patent number: 8115402
    Abstract: The present invention provides a method and apparatus for driving multiple parallel discharge lamps, which increases the switching frequency once the open lamp condition is detected to provide an output voltage that is high enough to ignite the lamp again.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: February 14, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Naixing Kuang, Lei Du, Junming Zhang, Yuancheng Ren
  • Patent number: 8102129
    Abstract: Embodiments of the present technology provide short-circuit detection and protection suitable for a discharge lamp system. In several embodiments, the transformer's primary current is sensed and used to provide short-circuit protection of the secondary winding side or high voltage side.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: January 24, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Kaiwei Yao, James C. Moyer, Wei Chen
  • Patent number: 8102680
    Abstract: The present invention discloses a smart driving method for a secondary synchronous rectifier of an isolated converter and its apparatus thereof. The apparatus comprises: a main circuit having a secondary synchronous rectifier Q1; a differentiation filter circuit, filtering the drain-source voltage Vds of the secondary synchronous rectifier, comprising a capacitor and at least one resistor connected in series and outputting a filtered voltage Vf from either between said capacitor and said at least one resistor or between said at least one resistor; a smart driver, receiving Vf and Vds and putting out a driving signal to the gate of the secondary synchronous rectifier. The control approach is fulfilled by comparing Vds to a reference voltage Vthr2 and comparing the absolute value of Vf to another reference voltage Vthr3. When Vds<Vthr2 and |Vf|>Vthr3, Q1 is turned on. When Vds>Vthr1, Q1 is turned off, where Vthr1 is a predetermined reference voltage.
    Type: Grant
    Filed: April 23, 2009
    Date of Patent: January 24, 2012
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Yuancheng Ren, Junming Zhang, Lei Miao, Zhaoqi Mao