Patents Assigned to Monolithic Power Systems
  • LOW LEAKAGE AND/OR LOW TURN-ON VOLTAGE SCHOTTKY DIODE
    Publication number: 20110156199
    Abstract: A Schottky diode and a method of manufacturing the Schottky diode are disclosed. The Schottky diode has an N-well or N-epitaxial layer with a first region, a second region substantially adjacent to an electron doped buried layer that has a donor electron concentration greater than that of the first region, and a third region substantially adjacent to the anode that has a donor electron concentration that is less than that of the first region. The second region may be doped with implanted phosphorus and the third region may be doped with implanted boron.
    Type: Application
    Filed: September 3, 2009
    Publication date: June 30, 2011
    Applicant: Monolithic Power Systems, Incc
    Inventors: Ji-Hyoung Yoo, Martin E. Garnett
  • System and method for implementing a single-wire serial protocol
    Patent number: 7944807
    Abstract: Methods and apparatus for a single-wire serial communication system are disclosed herein. In one embodiment, a method includes defining a predetermined short pulse as data to be transmitted and a predetermined long pulse as a data separator for the data to provide serial communication for a data stream.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: May 17, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Curtis B. Robinson, Jr.
  • Switching regulator with automatic multi mode conversion
    Patent number: 7944191
    Abstract: Methods and apparatus are disclosed for efficient switching regulators that adapt automatically to, and operate with, input voltages that are above, below, or equal to the output voltage. The disclosed switching regulators demonstrate advantages of both buck and boost converters at high efficiency.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: May 17, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Peng Xu
  • Chip scale package for power devices and method for making the same
    Patent number: 7944048
    Abstract: A chip scale package is disclosed that includes a semiconductor die further comprising an array of power buses electrically coupled to a high power integrated circuit, and a plurality of Under Bump Metallization (UBM) multi-layer power buses disposed parallel to one another and spanning substantially across the entire length of the semiconductor die. The plurality of multi-layer UBM power buses, electrically coupled to the array of power buses, further includes a thick metal layer configured in a geometric shape that have interconnection balls completely posited thereupon.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: May 17, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Hunt H. Jiang
  • Method and apparatus for synchronous buck with active negative current modulation
    Patent number: 7928713
    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: March 28, 2008
    Date of Patent: April 19, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • Mode control circuit for switching regulators and method therefor
    Patent number: 7915873
    Abstract: A mode control method and apparatus for a switching regulator is disclosed. The method receives an input signal and amplifying the input signal to get an amplified signal. The amplified signal is sent to a sample circuit to get a sample signal. The sample signal is delivered to an averaging circuit to get an averaged sensed output signal. The averaged sensed output signal is compared with a first pre-determined threshold or an second pre-determined threshold to get a PWM enable signal. The appropriate mode is determined based on the PWM enable signal.
    Type: Grant
    Filed: February 5, 2009
    Date of Patent: March 29, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Tami Yen
  • Single-ended DC to AC power inverter
    Patent number: 7915833
    Abstract: An inverter comprising a low-side switching element in series with a first primary winding; a high-side switching element in series with a second primary winding, where the combination of the low-side switching element and first primary winding is connected in parallel with the combination of the high-side switching element and the second primary winding; and a clamping capacitor having one terminal connected to the first primary winding and having a second terminal connected to the second primary winding. Other embodiments are described and claimed.
    Type: Grant
    Filed: February 25, 2008
    Date of Patent: March 29, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Wei Chen, Yuancheng Ren, Junming Zhang, Lei Du
  • Method and apparatus for controlling a discharge lamp in a backlighted display
    Patent number: 7911150
    Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: March 22, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: John Robert Shannon, James Copland Moyer, Michael Ren Hsing
  • Method and apparatus for fault detection scheme for cold cathode fluorescent lamp (CCFL) integrated circuits
    Patent number: 7894174
    Abstract: A fault detection circuit and a short-circuit detection circuit for a Cold Cathode Fluorescent Lamp (CCFL) driver integrated circuit having a power bridge and a CCFL load are disclosed that includes a reference circuit operable to generate a reference current in response to an external component, a replica component having a dimension substantially less than the components of the power bridge, a multiplexer circuit, and a comparator circuit. The replica component and the multiplexer circuit pass the reference current and the replica current to the comparator circuit respectively.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: February 22, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: James C. Moyer, Paul Ueunten
  • Method and apparatus for synchronous boost voltage regulators with active negative current modulation
    Patent number: 7893677
    Abstract: A switch-mode synchronous boost voltage regulator is disclosed that includes a boost voltage regulator and an active current modulator. The active current modulator detects a negative current flowing through the high-side switch during a light load condition. When the negative current is detected, the active current modulator is operable to maintain the high-side switch “on” in a linear mode and to limit the negative current to a predetermined current level.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: February 22, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • DC/DC voltage regulator with automatic current sensing selectability for linear and switch mode operation utilizing a single voltage reference
    Patent number: 7880456
    Abstract: A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator disabled, also maximizing the efficiency. Each regulator senses load current to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators to minimize the voltage transients.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: February 1, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Christopher T. Falvey, Andrew Wu
  • Short circuit current ratcheting in switch mode DC/DC voltage regulators
    Patent number: 7880455
    Abstract: A regulator with a high side pass device and a low side pass device coupled in series to the high side pass device is disclosed. The apparatus further includes a control module coupled to the high side pass device and the low side pass device. The control module is coupled to the high side pass device and the low side pass device to control the high side pass device and the low side pass device. The control module is operable to lock out the high side pass device under certain conditions.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: February 1, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Andrew Wu
  • Layout schemes and apparatus for high performance DC-DC output stage
    Patent number: 7882482
    Abstract: A layout method that enables a high power switch mode voltage regulator integrated circuit to generate a large output current and achieve substantially low switching loss is disclosed. The layout method includes forming an array of switching elements on a semiconductor die, each switching element including a plurality of discrete transistors configured to have a substantially reduced ON resistance; and forming a plurality of gate driver circuits on the same die among the switching elements, all using a single metal process. Each gate driver circuit placed substantially close to and dedicated to drive only one switching element so that the gate coupling capacitance resistance product is substantially reduced.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: February 1, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Paul Ueunten
  • Method for starting a discharge lamp using high energy initial pulse
    Patent number: 7880397
    Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). Additionally, during striking of the CCFL, a higher energy initial energy pulse is used. During normal operation, a lower energy pulse is used.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: February 1, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Timothy J. Rust, James C. Moyer, David Joseph Christy
  • Double-edge PWM controller and its control method thereof
    Patent number: 7880522
    Abstract: The present invention discloses a double-edge pulse width modulation (PWM) controller based on the output current and output voltage which is modulated in real time by the output current and the output voltage. The controller uses an extra first adder to sum up the compensation signal and a triangular signal (or a saw-tooth signal); a second adder to sum up the output current signal to a bias value; a PWM comparator, with its non-inverting input receiving the output of said first adder, its inverting input receiving the output of said second adder and outputs the PWM signal.
    Type: Grant
    Filed: June 2, 2009
    Date of Patent: February 1, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Qian Ouyang, Xiaoli Kong, Yuancheng Ren, Eric Yang
  • High-impedance level-shifting amplifier capable of handling input signals with a voltage magnitude that exceeds a supply voltage
    Patent number: 7876152
    Abstract: A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: January 25, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James Copland Moyer
  • Low-power voltage reference
    Patent number: 7872455
    Abstract: A circuit provides a voltage reference using very low power. It can also be used as a shut regulator for a quiescent current as low as 1.5 ?A. It includes a transconductance amplifier, a gain stage, and a power transistor. One embodiment of this invention utilizes a work function difference between p+ gate and n+ gate to generate a predetermined reference voltage. In another embodiment of this invention, the predetermined reference voltage can be pre-adjusted using gate materials with different work functions.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: January 18, 2011
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Farhood Moraveji, Michael Hsing
  • Method and apparatus for high performance class D audio amplifiers
    Patent number: 7843260
    Abstract: The present disclosure provides a method and apparatus for high performance class D audio amplifier circuit that includes: a modulator circuit for receiving a PWM input signal and generating a control signal, a driver control circuit, a switching circuit, and a feedback circuit. The driver control circuit is adapted to generate a drive signal for the switching circuit. The driving signal provides compensation for noise and distortions in a PWM output signal at each cycle by selecting either a first pulse signal or a second pulse signal based on the information of the control signal.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: November 30, 2010
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Jeff Kotowski, Qizhang Yin
  • Switching regulator circuit for operation as a switching device in a switching mode and a passive device in a passive mode
    Patent number: 7830128
    Abstract: A switching regulator circuit is provided for operation as a switching device in a switching mode and as a passive device in a passive mode. A controller is provided for operating the circuit in a switching mode and a passive mode. Additionally, a single transistor is provided for operating as a switching device in the switching mode and for further operating as a passive device in the passive mode.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: November 9, 2010
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Peng Xu
  • Method for controlling a universal backlight inverter
    Patent number: 7825883
    Abstract: The present invention introduces methods to modify the burst frequency of an inverter in a given LCD panel without any component change on the inverter board. The present invention also introduces methods to adjust the setting of a sensing system for duty cycles and accept Display Power Saving Technology (DPST) input signals with different frequencies. The universal inverter module with the present invention can be applied for different DPST technologies.
    Type: Grant
    Filed: April 13, 2007
    Date of Patent: November 2, 2010
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Kaiwei Yao