Patents Assigned to Monolithic Power Systems, Inc.
  • Bootstrap refresh control circuit, power converter and associated method
    Patent number: 9312773
    Abstract: A power converter having a bootstrap refresh control circuit and a method for controlling the power converter. The bootstrap refresh control circuit is configured to monitor a bootstrap voltage across a bootstrap capacitor and to provide an enhanced high side driving signal to a high side switch of the power converter. The bootstrap refresh control circuit is further configured to controlling the charging of the bootstrap capacitor through regulating the on and off switching of the high side switch and a low side switch based on the bootstrap voltage. The bootstrap refresh control circuit can refresh the bootstrap voltage in time to support driving the high side switch normally, without causing large spikes in an output voltage of the power converter and without influencing the power conversion efficiency of the power converter.
    Type: Grant
    Filed: August 30, 2013
    Date of Patent: April 12, 2016
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Yike Li
  • Constant on-time switching converter with internal ramp compensation and control method thereof
    Patent number: 9270176
    Abstract: A switching converter includes a main transistor, an inductor coupled to the main transistor, a feedback circuit configured to generate a feedback signal indicative of the output voltage and a controller configured to generate a control signal to control the main transistor. The controller has an on timer, a ramp generator, a comparing circuit and a logic circuit. The on timer is configured to generate an on-time control signal. The ramp generator is configured to generate a ramp signal, wherein the level of the ramp signal is regulated to be equal to the level of a common mode voltage when the status of the main transistor is changed from OFF to ON. The comparing circuit generates a comparison signal based on the ramp signal, the common mode voltage, a reference signal and the feedback signal. The logic circuit generates the control signal based on the on-time control signal and the comparison signal.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: February 23, 2016
    Assignee: Monolithic Power Systems, Inc.
    Inventors: James H. Nguyen, Jinghai Zhou
  • Short protection circuit for power switch and associated protection method
    Patent number: 9263937
    Abstract: A short protection circuit for protecting a power switch. The short protection circuit has a transistor and compares a differential voltage between a first end of the power switch and a second end of the power switch to a threshold voltage of the transistor only when the power switch is in an ON state; and wherein when the differential voltage is higher than the threshold voltage, the short protection circuit turns off the power switch.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: February 16, 2016
    Assignee: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • Power converter with active bleeding and ramp up-down delay and the method thereof
    Patent number: 9246404
    Abstract: The present disclosure discloses a power converter providing a low output voltage from an offline AC. The power converter defines a voltage window for the input AC signal. Inside the voltage window, the rectified DC waveform is passed through to the output and the storage capacitor; outside the voltage window, the power converter is idle (or the output is blocked from input) and let the output storage capacitor alone supply the load.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: January 26, 2016
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Joseph Urienza, Yiqing Jin
  • High voltage circuit layout structure
    Patent number: 9231121
    Abstract: A high voltage circuit layout structure has a P-type substrate; a first N-type tub, a second N-type tub, a third N-type tub, a first P-type tub with a first width and a second P-type tub with a second width formed on the P-type substrate; wherein the first P-type tub is formed between the first N-type tub and the second N-type tub; and the second P-type tub is formed between the second N-type tub and the third N-type tub.
    Type: Grant
    Filed: January 17, 2013
    Date of Patent: January 5, 2016
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Joseph Urienza
  • Junction field effect transistors and associated fabrication methods
    Patent number: 9230956
    Abstract: A JFET having a semiconductor substrate of a first doping type, an epitaxial layer of the first doping type located on the semiconductor substrate, a body region of a second doping type located in the epitaxial layer, a source region of the first doping type located in the epitaxial layer, a gate region of the second doping type located in the body region, and a shielding layer of the second doping type located in the epitaxial layer, wherein the semiconductor substrate is configured as a drain region, the shielding layer is in a conductive path formed between the source region and the drain region.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: January 5, 2016
    Assignee: Chengdu Monolithic Power Systems, Inc.
    Inventors: Rongyao Ma, Tiesheng Li, Lei Zhang, Daping Fu
  • High voltage PMOS and the method for forming thereof
    Patent number: 9219146
    Abstract: A high voltage PMOS replacing the lightly doped region of the drain region with a low voltage P-well adopted in the low voltage devices, so as to save a mask. In order to achieve the high breakdown voltage and the low on resistance, a thick gate oxide applied in the DMOS is inserted. The N-type well region surrounding the source region may be replaced by a low voltage N-well adopted in the low voltage device to further save a mask.
    Type: Grant
    Filed: December 27, 2013
    Date of Patent: December 22, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Ji-Hyoung Yoo, Yanjie Lian
  • Current detection and emulation circuit, and method thereof
    Patent number: 9184651
    Abstract: A current detection circuit for detecting a current in a SMPS which has a first switch and a second switch; a current sensing circuit sensing a second switch current flowing through the second switch and providing a current sensing signal; and a current emulation circuit which generates a first current according to the current sensing signal and generate a second current according to the first current source, and the current emulation circuit further providing a current emulation signal based on the first current source and the second current source; wherein a current detection signal during a first period is proportional to the current emulation signal, and the current detection signal during a second period is proportional to the current sensing signal.
    Type: Grant
    Filed: January 31, 2014
    Date of Patent: November 10, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: James H. Nguyen, Francis C. Yu
  • High side DMOS and the method for forming thereof
    Patent number: 9159795
    Abstract: A high side DMOS provides high breakdown voltage with small termination area. The high side DMOS has three parts which may comprise a stair-field plate in the termination part of the poly gate.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: October 13, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Ji-Hyoung Yoo, Lei Zhang, Daping Fu, Yanjie Lian
  • Power converter with voltage window and the method thereof
    Patent number: 9093903
    Abstract: The present disclosure discloses a power converter providing a low output voltage from an offline AC. The power converter defines a voltage window for the input AC signal. Inside the voltage window, the rectified DC waveform is passed through to the output and the storage capacitor; outside the voltage window, the power converter is idle (or the output is blocked from input) and let the output storage capacitor alone supply the load.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: July 28, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Rajesh Swaminathan, Joseph Urienza
  • LDMOS device with short channel and associated fabrication method
    Patent number: 9087774
    Abstract: A method of fabricating an LDMOS device includes: forming a gate of the LDMOS device on a semiconductor substrate; performing tilt body implantation by implanting dopants of a first conductivity type in the semiconductor substrate using a mask, wherein the tilt body implantation is implanted at an angle from a vertical direction; performing zero tilt body implantation by implanting dopants of the first conductivity type using the same mask, wherein the zero tilt body implantation is implanted with zero tilt from the vertical direction, and wherein the tilt body implantation and the zero tilt body implantation are configured to form a body region of the LDMOS device; and forming a source region and a drain contact region of the LDMOS device, wherein the source region and the drain contact region are of a second conductivity type.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: July 21, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Jeesung Jung, Joel M. McGregor, Ji-Hyoung Yoo
  • HIGH VOLTAGE PMOS AND THE METHOD FOR FORMING THEREOF
    Publication number: 20150187931
    Abstract: A high voltage PMOS replacing the lightly doped region of the drain region with a low voltage P-well adopted in the low voltage devices, so as to save a mask. In order to achieve the high breakdown voltage and the low on resistance, a thick gate oxide applied in the DMOS is inserted. The N-type well region surrounding the source region may be replaced by a low voltage N-well adopted in the low voltage device to further save a mask.
    Type: Application
    Filed: December 27, 2013
    Publication date: July 2, 2015
    Applicant: Monolithic Power Systems, Inc.
    Inventors: Ji-Hyoung Yoo, Yanjie Lian
  • Multi-phase SMPS with load transient control and associated control method
    Patent number: 9071142
    Abstract: The present invention discloses a multi-phase switch-mode power supply (SMPS). The multi-phase SMPS may comprise a plurality of comparing circuits and a controller. Wherein each comparing circuit comprises a first input coupled to a threshold voltage, a second input coupled to a feedback signal of the output voltage, and an output configured to provide a load indication signal. The controller may have a plurality of inputs coupled to the outputs of the comparing circuit, and a plurality of outputs configured to provide control signals for driving a plurality of switches of the multi-phase SMPS. And the controller is configured to selectively turn on a plurality of the switches according to the load indication signals.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: June 30, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Eric Yang, Lijie Jiang, Qian Ouyang, Xiaokang Wu, Bo Zhang
  • Microelectronic flip chip packages with solder wetting pads and associated methods of manufacturing
    Patent number: 9070671
    Abstract: Processes of assembling microelectronic packages with lead frames and/or other suitable substrates are described herein. In one embodiment, a method for fabricating a semiconductor assembly includes forming an attachment area and a non-attachment area on a lead finger of a lead frame. The attachment area is more wettable to the solder ball than the non-attachment area during reflow. The method also includes contacting a solder ball carried by a semiconductor die with the attachment area of the lead finger, reflowing the solder ball while the solder ball is in contact with the attachment area of the lead finger, and controllably collapsing the solder ball to establish an electrical connection between the semiconductor die and the lead finger of the lead frame.
    Type: Grant
    Filed: September 9, 2014
    Date of Patent: June 30, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Hunt Hang Jiang
  • A SWITCHING CIRCUIT AND THE METHOD THEREOF
    Publication number: 20150171855
    Abstract: A switching circuit having a low side driver providing a three-level low side drive signal keeps a low side power switch slightly on during a dead time between the low side power switch turn off and a high side power switch turn on, thus a current flowing through a body diode is mostly distributed to the slightly on low side power switch instead of the body diode.
    Type: Application
    Filed: December 13, 2013
    Publication date: June 18, 2015
    Applicant: Monolithic Power Systems, Inc.
    Inventor: Eric Braun
  • Energy harvest system and the method thereof
    Patent number: 9059633
    Abstract: The present disclosure discloses an energy harvest system converting an AC source provided by an energy harvester to a desired voltage. The AC source is boosted to the desired voltage by a bi-directional booster converter comprising fourth controllable transistors configured in an H-bridge, and stored by a storage capacitor. The desired voltage is then used to power various loads.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: June 16, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Eric Yang
  • Power device with integrated Schottky diode and method for making the same
    Patent number: 9059329
    Abstract: The present invention discloses a power device with integrated power transistor and Schottky diode and a method for making the same. The power device comprises a power transistor having a drain region, a Schottky diode in the drain region of the power transistor, and a trench-barrier near the Schottky diode. The trench-barrier is provided to reduce a reverse leakage current of the Schottky diode and minimizes the possibility of introducing undesired parasitic bipolar junction transistor in the power device.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: June 16, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Donald R. Disney
  • SHORT PROTECTION CIRCUIT FOR POWER SWITCH AND ASSOCIATED PROTECTION METHOD
    Publication number: 20150162819
    Abstract: A short protection circuit for protecting a power switch. The short protection circuit has a transistor and compares a differential voltage between a first end of the power switch and a second end of the power switch to a threshold voltage of the transistor only when the power switch is in an ON state; and wherein when the differential voltage is higher than the threshold voltage, the short protection circuit turns off the power switch.
    Type: Application
    Filed: December 11, 2013
    Publication date: June 11, 2015
    Applicant: Monolithic Power Systems, Inc.
    Inventor: James H. Nguyen
  • Power transistor and associated method for manufacturing
    Patent number: 9041102
    Abstract: The present disclosure discloses a lateral transistor and associated method for making the same. The lateral transistor comprises a gate formed over a first portion of a thin gate dielectric layer, and a field plate formed over a thick field dielectric layer and extending atop a second portion of the thin gate dielectric layer. The field plate is electrically isolated from the gate by a gap overlying a third portion of the thin gate dielectric layer and is electrically coupled to a source region. The lateral transistor according to an embodiment of the present invention may have reduced gate-to-drain capacitance, low specific on-resistance, and improved hot carrier lifetime.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: May 26, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventor: Joel M. McGregor
  • Light emitting diode driver systems and associated methods of control
    Patent number: 9035566
    Abstract: Light emitting diode (LED) dimming and driver systems and associated methods of control are disclosed herein. In one embodiment, a system comprises a PFC stage and an LED driver stage. The LED driver stage comprises an isolated converter and a controller responsive to a dimming signal to dim LED strings for backlight. The controller also regulates an output current of the isolated converter.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: May 19, 2015
    Assignee: Monolithic Power Systems, Inc.
    Inventors: Lei Du, Bairen Liu, Kaiwei Yao, Junming Zhang, Yuancheng Ren