Patents by Inventor Stefano Pietri

Stefano Pietri 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).

  • Patent number: 11709517
    Abstract: A bias current generator circuit includes a current path and a leakage control circuit. The current path is connected between a supply voltage and a ground level. The current path includes a transistor and a resistor. The transistor has a current channel connected in the current path. The resistor has an upper terminal and a lower terminal connected in the current path, and a well contact to allow a reverse leakage current of the resistor to flow through. The leakage control circuit is connected to the supply voltage. The leakage control circuit includes a driving transistor to provide a driving voltage to the well contact of the resistor, and to allow the reverse leakage current of the resistor to flow into the leakage control circuit.
    Type: Grant
    Filed: March 10, 2021
    Date of Patent: July 25, 2023
    Assignee: NXP USA, Inc.
    Inventors: Jiawei Fu, Jianzhou Wu, Jie Jin, Yikun Mo, Stefano Pietri
  • Patent number: 11619961
    Abstract: A bandgap reference correction circuit comprising a bandgap reference circuit comprising a first resistor; a first oscillator comprising a second resistor, wherein a frequency of a first oscillator output signal of the first oscillator depends on a resistance of the second resistor; and a compensation module configured to: receive the first oscillator output signal from the first oscillator and a reference frequency signal from a reference oscillator; determine the frequency of the first oscillator output signal using the reference frequency signal; and set a resistance of the first resistor based on the frequency of the first oscillator output signal.
    Type: Grant
    Filed: December 23, 2021
    Date of Patent: April 4, 2023
    Assignee: NXP USA, Inc.
    Inventors: Stefano Pietri, John Pigott
  • Publication number: 20230066987
    Abstract: A self-calibrating digital-to-analog converter (DAC) is disclosed. The self-calibrating DAC includes a DAC including a least significant bit (LSB) side resistor network and a most significant bit (MSB) side resistor network. At least the MSB side resistor network includes a plurality of trimmable resistors. A resistance to frequency converter coupled with an output of the DAC is included to generate a frequency fL based on a value of the LSB side resistor network or the MSB side resistor network. A monitor is included to generate a counter value by comparing fL with a high frequency clock having a constant frequency fH.
    Type: Application
    Filed: August 11, 2022
    Publication date: March 2, 2023
    Inventors: Yizhong Zhang, Jie Jin, Stefano Pietri, Michael Todd Berens, Hongyan Yao, Jiawei Fu
  • Patent number: 11588495
    Abstract: During a sampling phase, an analog front end circuit connects input of a first sampling capacitor to an analog input signal and input of a second sampling capacitor to a reference signal, and connects first and second hold capacitors to ground. During a partial tracking phase, input of the first sampling capacitor is connected to the reference voltage and the input of the second sampling capacitor is connected to the analog input signal. The first hold capacitor is connected to a first output of a gain amplifier and the second hold capacitor to a second output of the gain amplifier. Output of the first sampling capacitor is coupled to a first input of an amplifier and output of the second sampling capacitor is coupled to a second input of the amplifier.
    Type: Grant
    Filed: July 12, 2021
    Date of Patent: February 21, 2023
    Assignee: NXP USA, Inc.
    Inventors: Stefano Pietri, Michael Todd Berens, Yikun Mo, Ashutosh Jain
  • Publication number: 20230031469
    Abstract: A digital to analog converter (DAC) includes an amplifier including a buffer of the DAC, and a resistor ladder arrangement coupled to a non-inverting input terminal of the amplifier to generate a voltage based on a digital control word. The arrangement includes a first, least-significant bit, segment arranged in one of an R-2R or unit-R configuration, a second, most-significant bit, segment including one or more units each including a second-segment-resistor having a resistor terminal coupled to a respective second switch and having a second resistance, RMSB, and a third segment including one or more third-segment-resistors coupled in parallel to the non-inverting input terminal and connected to a first reference voltage terminal. M2 designates a number of bits in the digital control word for controlling the second switches, and the third segment has a total resistance, Rsp, based on M2.
    Type: Application
    Filed: July 14, 2022
    Publication date: February 2, 2023
    Inventors: Yizhong Zhang, Stefano Pietri, Jie Jin, Michael Todd Berens
  • Patent number: 11368126
    Abstract: A first switch is operable to couple a start-up oscillator circuit to a first crystal pin during operation in a start-up mode and decouple the start-up oscillator circuit from the first crystal pin during operation in a normal mode, and a second switch is operable to couple the start-up oscillator circuit to a second crystal pin during operation in the start-up mode and decouple the start-up oscillator circuit from the second crystal pin during operation in the normal mode. A switched oscillator circuit is coupled to the startup oscillator during operation in the startup mode, and to the first and second crystal pins during operation in the start-up and normal modes. The switched oscillator circuit includes a sample and charge circuit which is configured to sample a direct current (DC) level of the first crystal pin and pre-charge a first coupling capacitor during operation in the startup mode.
    Type: Grant
    Filed: August 3, 2021
    Date of Patent: June 21, 2022
    Assignee: NXP B.V.
    Inventors: Ricardo Pureza Coimbra, Stefano Pietri, Vitor Moreira Gomes, Eduardo Ribeiro da Silva
  • Publication number: 20220052707
    Abstract: During a sampling phase, an analog front end circuit connects input of a first sampling capacitor to an analog input signal and input of a second sampling capacitor to a reference signal, and connects first and second hold capacitors to ground. During a partial tracking phase, input of the first sampling capacitor is connected to the reference voltage and the input of the second sampling capacitor is connected to the analog input signal. The first hold capacitor is connected to a first output of a gain amplifier and the second hold capacitor to a second output of the gain amplifier. Output of the first sampling capacitor is coupled to a first input of an amplifier and output of the second sampling capacitor is coupled to a second input of the amplifier.
    Type: Application
    Filed: July 12, 2021
    Publication date: February 17, 2022
    Inventors: Stefano Pietri, Michael Todd Berens, Yikun Mo, Ashutosh Jain
  • Patent number: 11128306
    Abstract: A clock generation circuit includes a switched capacitor circuit for providing a discrete amount of charge to a resonator for sustaining energization of the resonator at specific portions of the clock cycle.
    Type: Grant
    Filed: July 15, 2020
    Date of Patent: September 21, 2021
    Assignee: NXP USA, INC.
    Inventors: Stefano Pietri, Juan Camilo Monsalve, Ricardo Pureza Coimbra, James Robert Feddeler
  • Publication number: 20210286389
    Abstract: A bias current generator circuit includes a current path and a leakage control circuit. The current path is connected between a supply voltage and a ground level. The current path includes a transistor and a resistor. The transistor has a current channel connected in the current path. The resistor has an upper terminal and a lower terminal connected in the current path, and a well contact to allow a reverse leakage current of the resistor to flow through. The leakage control circuit is connected to the supply voltage. The leakage control circuit includes a driving transistor to provide a driving voltage to the well contact of the resistor, and to allow the reverse leakage current of the resistor to flow into the leakage control circuit.
    Type: Application
    Filed: March 10, 2021
    Publication date: September 16, 2021
    Inventors: Jiawei Fu, Jianzhou Wu, Jie Jin, Yikun Mo, Stefano Pietri
  • Patent number: 10819279
    Abstract: A low power crystal oscillator is provided. The crystal oscillator includes a gain control stage, a filter stage, and an output stage. The gain control stage includes an input coupled at a first oscillator terminal configured and arranged for connection to a first terminal of a crystal. The filter stage includes an input coupled to an output of the gain control stage. The output stage includes a first transistor having a first current electrode coupled at a second oscillator terminal configured and arranged for connection to a second terminal of the crystal and a control electrode coupled to receive a voltage signal at the first oscillator terminal and a first bias voltage.
    Type: Grant
    Filed: June 28, 2019
    Date of Patent: October 27, 2020
    Assignee: NXP USA, INC.
    Inventors: Juan Camilo Monsalve, Ricardo Pureza Coimbra, James Robert Feddeler, Stefano Pietri
  • Patent number: 10790848
    Abstract: A digital to analog converter (DAC) that receives a binary coded signal and generates an analog output signal includes a binary-to-thermometer decoder and a resistive network. The decoder receives the binary coded signal, and decodes it into thermometer signals. The resistive network has branches that are coupled to an output terminal of the DAC in response to the thermometer signals. Each of the branches includes first and second resistors, and a switch. The first resistor is coupled between a first reference voltage and the switch, and the second resistor is coupled between a second reference voltage and the switch. The switch couples either the first resistor or the second resistor to the output terminal in response to a corresponding thermometer signal.
    Type: Grant
    Filed: January 1, 2019
    Date of Patent: September 29, 2020
    Assignee: NXP USA, Inc.
    Inventors: Yizhong Zhang, Stefano Pietri, James Robert Feddeler, Michael Todd Berens
  • Patent number: 10784886
    Abstract: A digital to analog converter receives a digital input consisting of first least significant bits, second most significant bits, and third middle significant bits. The digital to analog converter includes first, second, and third sub-DACs. The first sub-DAC receives the first least significant bits, and includes first resistors each contributing a respective voltage, to provide a first output. The second sub-DAC receives the second most significant bits, and includes second resistors each contributing a respective voltage, to provide a second output as an output of the digital to analog converter. The third sub-DAC is connected to the first sub-DAC to receive the first output, and receives the third middle significant bits, and includes third resistors each contributing a respective voltage, to provide a third output to the second sub-DAC. The first and third resistors each has a physical area less than an area of each second resistor.
    Type: Grant
    Filed: February 21, 2020
    Date of Patent: September 22, 2020
    Assignee: NXP USA, Inc.
    Inventors: Yizhong Zhang, Stefano Pietri, James Robert Feddeler, Michael Todd Berens
  • Patent number: 10784783
    Abstract: A DC-DC converter selectively operates in at least a first burst mode having at least one first-mode charge cycle with a first-mode charging phase followed by a first-mode discharging phase or a second burst mode having at least one second-mode charge cycle with a second-mode charging phase followed by a second-mode discharging phase. A first-mode charging phase is terminated when an inductor current flowing through the inductance reaches a first-mode peak-current threshold, and a first-mode discharging phase is terminated when the inductor current reaches a first-mode valley-current threshold.
    Type: Grant
    Filed: January 8, 2020
    Date of Patent: September 22, 2020
    Assignee: NXP B.V.
    Inventors: Jitendra Prabhakar Harshey, Hendrik Johannes Bergveld, Olivier Trescases, Edevaldo Pereira da Silva Junior, Stefano Pietri, Oscar Igor Robles Palacios
  • Patent number: 10763855
    Abstract: A circuit includes a high voltage (HV) transistor having a first current electrode, a second current electrode, and a control electrode coupled to receive a control signal. The HV transistor is configured and arranged to be non-conductive when the control signal is at a first state and conductive when the control signal is at a second state. A low voltage (LV) transistor is coupled to the first current electrode of the HV transistor. An HV pad is coupled to the second current electrode of the HV transistor. An operating voltage rating of the HV pad exceeds an operating voltage rating of the LV transistor. A secondary electrostatic discharge protection device is coupled between the second current electrode of the HV transistor and a voltage supply terminal.
    Type: Grant
    Filed: December 16, 2019
    Date of Patent: September 1, 2020
    Assignee: NXP USA, INC.
    Inventors: Ashutosh Jain, Michael A Stockinger, Stefano Pietri, Jaideep Banerjee, Ateet Omer
  • Patent number: 10720838
    Abstract: Embodiments provide forced-burst voltage regulation for burst mode direct-current-to-direct-current (DC-DC) converters in integrated circuits. The DC-DC converter generates an output voltage and operates in a burst mode to raise the output voltage to a threshold voltage. A controller is coupled to the DC-DC converter. In operation, the DC-DC converter is configured to perform the burst mode based upon a low-voltage detection for the output voltage. The DC-DC converter is further configured to perform the burst mode when a force-burst command is asserted by the controller to the DC-DC converter regardless of a state for the low-voltage detection. For one embodiment, the force-burst command is asserted as a burst control signal from the controller to the DC-DC converter to generate a long quiet period for sensitive actions. For another embodiment, the force-burst command is asserted using enable and refresh control signals to facilitate low-power operation.
    Type: Grant
    Filed: June 5, 2019
    Date of Patent: July 21, 2020
    Assignee: NXP B.V.
    Inventors: Jitendra Prabhakar Harshey, Olivier Trescases, Edevaldo Pereira Da Silva Junior, Stefano Pietri, Jurgen Geerlings, Hendrik Johannes Bergveld
  • Patent number: 10659038
    Abstract: A method of powering up a circuit includes powering up a latch circuit in a known latch state by applying a first power supply voltage differential of a first voltage domain across power supply terminals of the latch circuit. A current diode inhibits current diode in a current path between a latch node of the latch circuit and a power supply terminal when the power supply voltage differential is below a threshold voltage during the powering up in which the inhibiting prevents the latch circuit from switching from the known latch state during the powering up.
    Type: Grant
    Filed: March 12, 2019
    Date of Patent: May 19, 2020
    Assignee: NXP USA, Inc.
    Inventors: Robert Matthew Mertens, James Robert Feddeler, Stefano Pietri
  • Patent number: 10509428
    Abstract: A first voltage scaling power switch is coupled to a first power supply terminal for providing power to a first circuit portion, and a second voltage scaling power switch is coupled between the first power supply terminal providing power to a second circuit portion. A common power rail is coupled the first and second power input nodes during respective voltage scaling modes of the first and second circuit portions. A feedback circuit coupled to the common power rail provides a feedback signal to a control input of the first voltage scaling power switch to regulate a voltage provided by the first power switch, and to a control input of the second voltage scaling power switch to regulate a voltage provided by the second voltage scaling power switch.
    Type: Grant
    Filed: April 29, 2019
    Date of Patent: December 17, 2019
    Assignee: NXP USA, INC.
    Inventors: Dale John McQuirk, Miten H. Nagda, Nidhi Chaudhry, James Robert Feddeler, Stefano Pietri, Simon Gallimore
  • Publication number: 20190372586
    Abstract: A digital to analog converter (DAC) that receives a binary coded signal and generates an analog output signal includes a binary-to-thermometer decoder and a resistive network. The decoder receives the binary coded signal, and decodes it into thermometer signals. The resistive network has branches that are coupled to an output terminal of the DAC in response to the thermometer signals. Each of the branches includes first and second resistors, and a switch. The first resistor is coupled between a first reference voltage and the switch, and the second resistor is coupled between a second reference voltage and the switch. The switch couples either the first resistor or the second resistor to the output terminal in response to a corresponding thermometer signal.
    Type: Application
    Filed: January 1, 2019
    Publication date: December 5, 2019
    Inventors: Yizhong Zhang, Stefano Pietri, James Robert Feddeler, Michael Todd Berens
  • Patent number: 10394264
    Abstract: A back bias voltage generator circuit includes a first resistive element connected in series with a second resistive element; a first amplifier having a first input coupled to an input voltage, a second input coupled to a first node at a first terminal of the first resistive element, and an output coupled to an N-polarity metal-oxide semiconductor (NMOS) bias voltage node. A second amplifier has a first input coupled to a symmetrical voltage, a second input coupled to a second node between a second terminal of the first resistive element and a first terminal of the second resistive element, and an output coupled to a P-polarity metal-oxide semiconductor (PMOS) bias voltage node and the second terminal of the second resistive element. The symmetrical voltage is between a highest supply voltage and a lowest supply voltage coupled to the first amplifier.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: August 27, 2019
    Assignee: NXP USA, Inc.
    Inventors: Ricardo Pureza Coimbra, Javier Mauricio Olarte Gonzalez, Ivan Carlos Ribeiro do Nascimento, Felipe Ricardo Clayton, Stefano Pietri, Charles Eric Seaberg
  • Publication number: 20190250656
    Abstract: A back bias voltage generator circuit includes a first resistive element connected in series with a second resistive element; a first amplifier having a first input coupled to an input voltage, a second input coupled to a first node at a first terminal of the first resistive element, and an output coupled to an N-polarity metal-oxide semiconductor (NMOS) bias voltage node. A second amplifier has a first input coupled to a symmetrical voltage, a second input coupled to a second node between a second terminal of the first resistive element and a first terminal of the second resistive element, and an output coupled to a P-polarity metal-oxide semiconductor (PMOS) bias voltage node and the second terminal of the second resistive element. The symmetrical voltage is between a highest supply voltage and a lowest supply voltage coupled to the first amplifier.
    Type: Application
    Filed: February 9, 2018
    Publication date: August 15, 2019
    Inventors: Ricardo Pureza Coimbra, Javier Mauricio Olarte Gonzalez, Ivan Carlos Ribeiro do Nascimento, Felipe Ricardo Clayton, Stefano Pietri, Charles Eric Seaberg