Patents by Inventor Serban-Mihai Popescu
Serban-Mihai Popescu 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).
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Publication number: 20090309562Abstract: A power regulator for converting an input voltage to an output voltage includes a pass device, a reference signal circuit and an error amplifier. The pass device receives the input voltage and provides the output voltage at an output terminal of the power regulator. The reference signal circuit coupled to the output terminal is powered by the output voltage to provide a reference signal. The error amplifier coupled to the pass device is powered by the output voltage to compare the reference signal with a feedback signal indicative of the output voltage. The error amplifier can generate a control signal according to a result of the comparison to drive the pass device.Type: ApplicationFiled: May 26, 2009Publication date: December 17, 2009Inventors: Laszlo LIPCSEI, Serban Mihai POPESCU
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Patent number: 7598718Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.Type: GrantFiled: April 10, 2007Date of Patent: October 6, 2009Assignee: O2Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20090184380Abstract: A transistor comprises a substrate of a first conductivity type, a drain region and a source region of a second conductivity type, a gate, a gate oxide layer, an adjustment implant region of the first conductivity type and a planar junction. The drain region and the source region are disposed in the substrate. The gate is placed over the substrate between the source region and the drain region. The gate is separated from the substrate by the gate oxide layer. The adjustment implant region is disposed under the gate oxide layer and in the substrate. A second doping concentration of the adjustment implant region is higher than a first doping concentration of the substrate. The adjustment implant region and the drain region in a predetermined shape form the planar junction with a surface curvature pointing towards the drain region to relax electrical field intensity at a location of the planar junction.Type: ApplicationFiled: January 16, 2009Publication date: July 23, 2009Inventors: Marian Udrea Spenea, Serban Mihai Popescu, Laszlo Lipcsei
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Patent number: 7501886Abstract: An amplifier that receives an input signal and outputs an amplified output signal includes an integration stage, a comparison stage, and a full bridge circuit. The integration stage is be used for receiving a constant common mode voltage, for receiving a first signal representing the input signal of the amplifier, and for generating a ramp signal. The comparison stage coupled to the integration stage is used for generating a pulse width modulation signal according to the ramp signal and according to a hysteretic signal. The full bridge circuit coupled to the comparison stage is used for receiving a power supply and the pulse width modulation signal, and for generating the output of the amplifier.Type: GrantFiled: January 17, 2008Date of Patent: March 10, 2009Assignee: O2Micro, Inc.Inventors: Marius Padure, Laszlo Lipcsei, Serban-Mihai Popescu
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Patent number: 7466113Abstract: A driver package includes an integrated circuit (IC) comprising pull up circuitry capable of turning ON an associated switch and pull down circuitry capable of turning OFF the associated switch. The pull up circuitry may be coupled to a first bonding pad of the IC, and the pull down circuitry may be coupled to a second bonding pad of the IC. The driver package may further comprise a first conductive path coupled between the first bonding pad and a package pin of the driver package, where the package pin is coupled to the associated switch, and a second conductive path coupled between the second bonding pad and the package pin. The first conductive path may further provide a sensed signal representative of state of the associated switch to break before make control circuitry to assist in minimizing a break before make delay time interval.Type: GrantFiled: July 7, 2004Date of Patent: December 16, 2008Assignee: 02Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20080224681Abstract: A controller for a DC to DC converter. The controller may include a resistor coupled to a switching node of the DC to DC converter. The switching node may be coupled to a high side switch and a low side switch of the DC to DC converter. A current level through the resistor may be responsive to a state of the high side switch and said low side switch. The controller may further include ramp generation circuitry responsive to the current level through the resistor to provide a ramp signal, and pulse width modulation (PWM) circuitry configured to generate a PWM signal in response to at least the ramp signal.Type: ApplicationFiled: March 24, 2008Publication date: September 18, 2008Applicant: O2MICRO, INC.Inventors: Marius Padure, Serban-Mihai Popescu, Laszlo Lipcsei
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Publication number: 20080150628Abstract: An amplifier that receives an input signal and outputs an amplified output signal includes an integration stage, a comparison stage, and a full bridge circuit. The integration stage is be used for receiving a constant common mode voltage, for receiving a first signal representing the input signal of the amplifier, and for generating a ramp signal. The comparison stage coupled to the integration stage is used for generating a pulse width modulation signal according to the ramp signal and according to a hysteretic signal. The full bridge circuit coupled to the comparison stage is used for receiving a power supply and the pulse width modulation signal, and for generating the output of the amplifier.Type: ApplicationFiled: January 17, 2008Publication date: June 26, 2008Inventors: Marius Padure, Laszio Lipcsei, Serban-Mihai Popescu
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Publication number: 20080129522Abstract: A battery pack is disclosed. The battery pack includes a battery cell and a cell monitor. The cell monitor is embedded in the battery cell and is operable for monitoring the battery cell and for generating an alert signal indicative of a predetermined condition of the battery cell.Type: ApplicationFiled: November 30, 2007Publication date: June 5, 2008Inventors: Bill Densham, James Keim, Serban-Mihai Popescu
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Publication number: 20070176587Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.Type: ApplicationFiled: April 10, 2007Publication date: August 2, 2007Applicant: O2MICRO INTERNATIONAL LIMITEDInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Patent number: 7202650Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.Type: GrantFiled: November 9, 2005Date of Patent: April 10, 2007Assignee: O2Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20060284608Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.Type: ApplicationFiled: August 29, 2006Publication date: December 21, 2006Applicant: O2MICRO INTERNATIONAL LIMITEDInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Patent number: 7098642Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.Type: GrantFiled: January 18, 2005Date of Patent: August 29, 2006Assignee: O2Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20060061343Abstract: A DC to DC converter to convert an input voltage to an output voltage. The DC to DC converter may include a pair of switches including a high side switch and a low side switch, an inductor coupled to the pair of switches; and a controller. The controller may be configured to estimate a zero crossing of an inductor current through the inductor without directly measuring said inductor current. An associated method is also provided.Type: ApplicationFiled: November 9, 2005Publication date: March 23, 2006Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20060006932Abstract: A driver package includes an integrated circuit (IC) comprising pull up circuitry capable of turning ON an associated switch and pull down circuitry capable of turning OFF the associated switch. The pull up circuitry may be coupled to a first bonding pad of the IC, and the pull down circuitry may be coupled to a second bonding pad of the IC. The driver package may further comprise a first conductive path coupled between the first bonding pad and a package pin of the driver package, where the package pin is coupled to the associated switch, and a second conductive path coupled between the second bonding pad and the package pin. The first conductive path may further provide a sensed signal representative of state of the associated switch to break before make control circuitry to assist in minimizing a break before make delay time interval.Type: ApplicationFiled: July 7, 2004Publication date: January 12, 2006Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Patent number: 6965221Abstract: A controller for a DC to DC converter is configured to provide a PWM signal in a first state during a first time interval based on an input voltage less a voltage level representative of an output voltage of the DC to DC converter. The controller may provide the PWM signal in the first state based on the time it takes to charge an energy storage element of the controller to a predetermined level. The controller may also provide an estimator of a zero inductor current level in an associated inductor when the energy storage element is completely discharged. The controller may also be a digital controller that counts time pulses to provide the PWM signal. A DC to DC converter including such a controller and associated methods are also provided.Type: GrantFiled: March 14, 2003Date of Patent: November 15, 2005Assignee: O2Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20050134247Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.Type: ApplicationFiled: January 18, 2005Publication date: June 23, 2005Inventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Patent number: 6850039Abstract: A battery pack including at least one battery cell; first and second battery selector switches configured to allow selective coupling of the battery cell to a power source or load for charging/discharging the battery cell; and a switch controller. The switch controller closes both of the switches to allow charging/discharging of the battery cell when a minimum charge/discharge current level is reached. A battery charging/discharging circuit including such a battery pack and a method of controlling the charging and discharging a battery cell in a battery pack are also provided.Type: GrantFiled: May 2, 2003Date of Patent: February 1, 2005Assignee: O2Micro International LimitedInventor: Serban-Mihai Popescu
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Patent number: 6844710Abstract: A switching circuit includes at least one switch, and a controller configured to provide a periodic control signal. The switch is responsive to the periodic control signal to change states with a start of each period, and a frequency of the periodic control signal has a predetermined minimum frequency level greater than an audible frequency limit for humans. The switching circuit may be used to control a high side switch and a low side switch in a DC to DC converter. A controller having an input voltage sensing circuit to sense an input of a DC to DC converter without using an additional input pin is also provided. Related methods are also provided. A dual phase controller having a phase selection circuit to select between phases is also provided.Type: GrantFiled: September 23, 2003Date of Patent: January 18, 2005Assignee: O2Micro International LimitedInventors: Laszlo Lipcsei, Serban-Mihai Popescu
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Publication number: 20040217737Abstract: A battery pack including at least one battery cell; first and second battery selector switches configured to allow selective coupling of the battery cell to a power source or load for charging/discharging the battery cell; and a switch controller. The switch controller closes both of the switches to allow charging/discharging of the battery cell when a minimum charge/discharge current level is reached. A battery charging/discharging circuit including such a battery pack and a method of controlling the charging and discharging a battery cell in a battery pack are also provided.Type: ApplicationFiled: May 2, 2003Publication date: November 4, 2004Inventor: Serban-Mihai Popescu
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Publication number: 20040114398Abstract: A switching circuit includes at least one switch, and a controller configured to provide a periodic control signal. The switch is responsive to the periodic control signal to change states with a start of each period, and a frequency of the periodic control signal has a predetermined minimum frequency level greater than an audible frequency limit for humans. The switching circuit may be used to control a high side switch and a low side switch in a DC to DC converter. A controller having an input voltage sensing circuit to sense an input of a DC to DC converter without using an additional input pin is also provided. Related methods are also provided. A dual phase controller having a phase selection circuit to select between phases is also provided.Type: ApplicationFiled: September 23, 2003Publication date: June 17, 2004Inventors: Laszlo Lipcsei, Serban-Mihai Popescu