Patents by Inventor Osvaldo Enrico Zambetti

Osvaldo Enrico Zambetti 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: 20160087527
    Abstract: A method is provided for controlling a converter of the multiphase interleaving type. According to the method, there is detected when a change of the load applied to an output terminal of the converter occurs. All the phases of the converter are simultaneously turned off, and a driving interleaving phase shift is recovered so as to restart a normal operation of the converter. A controller for carrying out such a method is also provided.
    Type: Application
    Filed: November 30, 2015
    Publication date: March 24, 2016
    Inventors: Alessandro Zafarana, Osvaldo Enrico Zambetti
  • Publication number: 20150222193
    Abstract: A resonant converter includes a primary switching circuit having a primary winding and a primary switching stage configured to drive the primary winding; a secondary resonant circuit having a secondary winding magnetically coupled to the primary winding, a resonance capacitor connected in parallel to the secondary winding, and first and second secondary inductors respectively coupled between an output terminal of the converter and respective terminals of the resonance capacitor; a rectification stage connected in parallel with the resonance capacitor, and having first and second switches coupled to form a half-bridge; and a feedback command circuit. The command circuit is configured to receive feedback signals representing an output voltage and an output current at the output terminal of the resonant converter, receive voltages at the terminals of the resonance capacitor, and turn on/off, independently with respect to each other, the switches of the rectification stage and the primary switching stage.
    Type: Application
    Filed: February 2, 2015
    Publication date: August 6, 2015
    Inventors: Osvaldo Enrico Zambetti, Stefano Saggini
  • Patent number: 9097592
    Abstract: A sensing device includes a first current mirror configured to mirror a current flowing through a thermistor, a second current mirror configured to mirror a current flowing through a reference resistor a comparator configured to compare voltages on the thermistor and the resistor, and a counter configured to generate a control signal representative of a temperature difference based on the comparison. The control signal controls a mirroring ratio of the second current mirror. The sensing device may be employed to generate a droop current of a voltage regulator.
    Type: Grant
    Filed: August 31, 2012
    Date of Patent: August 4, 2015
    Assignee: STMicroelectronics S.r.l.
    Inventors: Osvaldo Enrico Zambetti, Dario Zambotti
  • Patent number: 9018930
    Abstract: A current generator includes a thermistor configured to receive an input current, a reference resistor having a resistance substantially corresponding to a resistance of said thermistor at a reference temperature, a current mirror configured to generate a mirrored current proportional to said input current, a feedback circuit configured to generate an output compensation current proportional to a difference between voltages on said reference resistor and on said thermistor, and a first adder configured to force through said reference resistor a difference current between said mirrored replica current and said output compensation current.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: April 28, 2015
    Assignee: STMicroelectronics S.r.l.
    Inventor: Osvaldo Enrico Zambetti
  • Patent number: 8981743
    Abstract: A switching voltage regulator including a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal corresponding to a difference between the reference voltage and the feedback voltage, an offset module configured to generate an offset signal based on a number of active phases of the voltage regulator, an adder configured to generate a control signal based on the comparison signal and the offset signal, a plurality of pulse-width-modulated (PWM) power stages, and a control module configured to control the plurality of PWM power stages based at least in part on the control signal generated by the adder.
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: March 17, 2015
    Assignee: STMicroelectronics S.r.l.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Patent number: 8970195
    Abstract: A method is provided for controlling turn-on of phases of a multiphase regulator. According to the method, there are tested the conditions necessary for the turn-on of a phase to be turned-on indicated by a first cell of the phase register, and in response to a positive result a corresponding ramp signal is reset. There is then tested the conditions necessary for the turn-on of a phase successive to the phase to be turned on according to the list of priorities of the phase register, and corresponding ramp signals are reset if there is a positive result. In response to no positive results of testing conditions necessary for the turn-on of all phases successive to the phase to be turned on, there is reset a ramp signal corresponding to a phase successive to a last turned on phase indicated by a last cell of the phase register.
    Type: Grant
    Filed: June 10, 2010
    Date of Patent: March 3, 2015
    Assignee: STMicroelectronics S.r.l.
    Inventors: Osvaldo Enrico Zambetti, Alessandro Zafarana
  • Patent number: 8963519
    Abstract: A switching voltage regulator includes a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage, and a control module configured to generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage. The control module may be configured to control a duration of a PWM pulse based on the at least one of the reference voltage and the feedback voltage. The feedback voltage may a regulated output voltage of the switching voltage regulator. The switching voltage regulator may be implemented in an analog or a digital manner.
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: February 24, 2015
    Assignee: STMicroelectronics S.r.l.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Patent number: 8878503
    Abstract: The voltage regulators are capable of limiting undershoots of the output voltage without having a similar effect on overshoots because of the presence of a current cancellation network, input with the reference voltage and coupled to the second input of the error amplifier. This current cancellation network is adapted to inject into the second input a unidirectional compensation current of the first and second currents injected by the first and second feedback networks, respectively, the compensation current being determined by time variations of the difference between a replica of the output regulated voltage and the reference voltage and/or by time variations of the reference voltage.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: November 4, 2014
    Assignee: STMicroelectronics S.R.L.
    Inventors: Alessandro Zafarana, Osvaldo Enrico Zambetti
  • Publication number: 20140062430
    Abstract: In a multi-phase power supply voltage regulator functioning at a nominal switching frequency, one or more phases are kept off for optimizing energy efficiency at relatively low load conditions. Reactivation of stand-by phases in response to a load increase transient is made more efficiently by exploiting information already present in the output voltage control loop. The technique comprises a) deriving from the control loop information on the equivalent nominal switching frequency given by the product of the nominal switching frequency by the number of active phases; b) updating at every beat of a clock signal the instantaneous value of the equivalent switching frequency; c) determining the band of equivalent switching frequency values to which the instantaneous value belongs; d) logically combining the equivalent switching frequency information with a determined band of output current level, for switching on one or more stand-by phases in response to a load increase transient.
    Type: Application
    Filed: August 30, 2013
    Publication date: March 6, 2014
    Applicant: STMicroelectronics S.r.I.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti, Alessandro Zafarana
  • Patent number: 8432656
    Abstract: A feedback control method of a pulse width modulator (PWM) voltage converter may include generating a control voltage as a sum of an offset voltage and an error signal representing a difference between a scaled replica of a regulated output voltage of the voltage converter and a reference voltage, comparing the control voltage with a ramp signal, the comparing operation generating PWM driving signals for the voltage converter, comparing the regulated output voltage of the voltage converter with an overshoot threshold, and reducing the control voltage when the overshoot threshold is exceeded.
    Type: Grant
    Filed: June 9, 2010
    Date of Patent: April 30, 2013
    Assignee: STMicroelectronics S.r.l.
    Inventor: Osvaldo Enrico Zambetti
  • Patent number: 8400132
    Abstract: A circuit may generate a clock signal with a variable period given by a ratio between an initial switching period and a number of phase circuits through which a current of a multi-phase PWM voltage converter flows. The circuit may include an adjustable current generator driven by a signal representing the number of phase circuits through which the current flows and configured to generate a current proportional to the number of phase circuits through which the current flows, and a tank capacitor charged by the adjustable current generator. The circuit may include a comparator of a voltage on the tank capacitor with a threshold value configured to generate a pulse of the clock signal when the threshold value is attained, and a discharge path of the tank capacitor, the discharge path being enabled during the pulses of the clock signal.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: March 19, 2013
    Assignee: STMicroelectronics S.R.L.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Publication number: 20130057242
    Abstract: A switching voltage regulator including a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal corresponding to a difference between the reference voltage and the feedback voltage, an offset module configured to generate an offset signal based on a number of active phases of the voltage regulator, an adder configured to generate a control signal based on the comparison signal and the offset signal, a plurality of pulse-width-modulated (PWM) power stages, and a control module configured to control the plurality of PWM power stages based at least in part on the control signal generated by the adder.
    Type: Application
    Filed: July 9, 2012
    Publication date: March 7, 2013
    Applicant: STMICROELECTRONICS S.R.L.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Publication number: 20130058378
    Abstract: A sensing device includes a first current mirror configured to mirror a current flowing through a thermistor, a second current mirror configured to mirror a current flowing through a reference resistor a comparator configured to compare voltages on the thermistor and the resistor, and a counter configured to generate a control signal representative of a temperature difference based on the comparison. The control signal controls a mirroring ratio of the second current mirror. The sensing device may be employed to generate a droop current of a voltage regulator.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 7, 2013
    Applicant: STMicroelectronics S.r.I.
    Inventors: Osvaldo Enrico Zambetti, Dario Zambotti
  • Publication number: 20130057240
    Abstract: A switching voltage regulator includes a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage, and a control module configured to generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage. The control module may be configured to control a duration of a PWM pulse based on the at least one of the reference voltage and the feedback voltage. The feedback voltage may a regulated output voltage of the switching voltage regulator. The switching voltage regulator may be implemented in an analog or a digital manner.
    Type: Application
    Filed: July 9, 2012
    Publication date: March 7, 2013
    Applicant: STMicroelectronics S.r.l.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Publication number: 20120313605
    Abstract: A circuit may generate a clock signal with a variable period given by a ratio between an initial switching period and a number of phase circuits through which a current of a multi-phase PWM voltage converter flows. The circuit may include an adjustable current generator driven by a signal representing the number of phase circuits through which the current flows and configured to generate a current proportional to the number of phase circuits through which the current flows, and a tank capacitor charged by the adjustable current generator. The circuit may include a comparator of a voltage on the tank capacitor with a threshold value configured to generate a pulse of the clock signal when the threshold value is attained, and a discharge path of the tank capacitor, the discharge path being enabled during the pulses of the clock signal.
    Type: Application
    Filed: August 22, 2012
    Publication date: December 13, 2012
    Applicant: STMICROELECTRONICS S.R.L.
    Inventors: OSVALDO ENRICO ZAMBETTI, DANIELE GIORGETTI
  • Patent number: 8305062
    Abstract: An embodiment of method is described for controlling a voltage regulator of the type comprising at least one modulator of the PWM type, the method comprising: 1) generation of a control voltage signal for said PWM modulator; 2) frequency modulation of said control voltage signal obtaining a modulated control voltage signal having an harmonic at a switching frequency of said voltage regulator of reduced entity with respect to said control voltage signal; and 3) application of said modulated control voltage signal to said PWM modulator for generating a driving signal for said voltage regulator.
    Type: Grant
    Filed: June 11, 2009
    Date of Patent: November 6, 2012
    Assignee: STMicroelectronics S.r.l.
    Inventors: Alessandro Zafarana, Osvaldo Enrico Zambetti, Andrea Cappelletti
  • Patent number: 8258769
    Abstract: A circuit may generate a clock signal with a variable period given by a ratio between an initial switching period and a number of phase circuits through which a current of a multi-phase PWM voltage converter flows. The circuit may include an adjustable current generator driven by a signal representing the number of phase circuits through which the current flows and configured to generate a current proportional to the number of phase circuits through which the current flows, and a tank capacitor charged by the adjustable current generator. The circuit may include a comparator of a voltage on the tank capacitor with a threshold value configured to generate a pulse of the clock signal when the threshold value is attained, and a discharge path of the tank capacitor, the discharge path being enabled during the pulses of the clock signal.
    Type: Grant
    Filed: June 9, 2010
    Date of Patent: September 4, 2012
    Assignee: STMicroelectronics S.R.L.
    Inventors: Osvaldo Enrico Zambetti, Daniele Giorgetti
  • Publication number: 20120161741
    Abstract: A current generator includes a thermistor configured to receive an input current, a reference resistor of a value substantially corresponding to a resistance of said thermistor at a reference temperature, a current mirror configured to generate a mirrored current proportional to said input current, a feedback circuit configured to generate an output compensation current proportional to a difference between voltages on said reference resistor and on said thermistor, and a first adder configured to force through said reference resistor a difference current between said mirrored replica current and said output compensation current.
    Type: Application
    Filed: December 21, 2011
    Publication date: June 28, 2012
    Applicant: STMicroelectronics S.r.l
    Inventor: Osvaldo Enrico Zambetti
  • Publication number: 20120081090
    Abstract: The voltage regulators are capable of limiting undershoots of the output voltage without having a similar effect on overshoots because of the presence of a current cancellation network, input with the reference voltage and coupled to the second input of the error amplifier. This current cancellation network is adapted to inject into the second input a unidirectional compensation current of the first and second currents injected by the first and second feedback networks, respectively, the compensation current being determined by time variations of the difference between a replica of the output regulated voltage and the reference voltage and/or by time variations of the reference voltage.
    Type: Application
    Filed: September 21, 2011
    Publication date: April 5, 2012
    Applicant: STMicroelectronics S.r.I.
    Inventors: Alessandro ZAFARANA, Osvaldo Enrico Zambetti
  • Publication number: 20120049900
    Abstract: A DC-DC converter based switching voltage regulator circuit is for powering a microprocessor including regulated power supplies configured to produce different output voltages. The DC-DC converter has an output power stage configured to generate a regulated DC supply voltage and comprising a plurality of power transistors. A driver circuit is configured to drive the plurality of power transistors at an adjustable drive voltage in response to a drive control signal. Circuitry is configured to adaptively adjust the adjustable drive voltage and has a voltage selector configured to select between at least two different output voltages for the regulated power supplies of the microprocessor to be coupled to the driver circuit. The voltage selector is controlled by a state logic signal generated based upon logic signals generated by the microprocessor, the state logic signal indicating whether the microprocessor is entering a given power state.
    Type: Application
    Filed: August 23, 2011
    Publication date: March 1, 2012
    Applicant: STMicroelectronics S.r.l.
    Inventors: Alessandro ZAFARANA, Cristian Porta, Osvaldo Enrico Zambetti