Patents by Inventor Madan Mohan Reddy Vemula

Madan Mohan Reddy Vemula 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: 10998897
    Abstract: A power switch over current protection system including a power switch transistor configured to deliver a power current from a power source to power load, a power switch driver configured to control and on/off state of the power switch, an over current protection (OCP) circuit to detect a threshold value of the power current, a discharge transistor configured to discharge a parasitic capacitance of the power switch transistor, and a system state machine to receive a signal from the OCP circuit configured to control an action of the power switch driver and discharge transistor depending on the level of the power current.
    Type: Grant
    Filed: October 25, 2018
    Date of Patent: May 4, 2021
    Assignee: NXP B.V.
    Inventors: Xiaoqun Liu, Madan Mohan Reddy Vemula
  • Patent number: 10826386
    Abstract: A multi-stage charge pump including a first stage configured to generate a first output voltage, a last stage configured to receive the first output voltage from the first stage and output a second output voltage, a switch configured to receive the second output voltage from the last stage, and a voltage regulator circuit configured to control the second output voltage of the last stage to maintain a substantially constant on-resistance of the switch.
    Type: Grant
    Filed: October 26, 2018
    Date of Patent: November 3, 2020
    Assignee: NXP B.V.
    Inventors: Xiaoqun Liu, Madan Mohan Reddy Vemula
  • Patent number: 10826290
    Abstract: Embodiments of an electrostatic discharge (ESD) protection device and a method of operating an ESD protection device are described. In one embodiment, the ESD protection circuit is connected between a VDD rail and a VSS rail and includes an internal floating ESD rail located between the VDD rail and the VSS rail, I/O pins connected between the internal floating ESD rail and the VSS rail, ESD diodes corresponding to at least one I/O pin, an internal bias cell corresponding to an I/O pin and configured to short the corresponding I/O pin to the internal floating ESD rail when the I/O pin is pulled high, and an internal bias cell corresponding to a VDD pin of the VDD rail and configured to short the VDD rail to the internal floating ESD rail when the VDD pin is pulled high.
    Type: Grant
    Filed: December 23, 2016
    Date of Patent: November 3, 2020
    Assignee: NXP B.V.
    Inventors: Gijs Jan de Raad, Madan Mohan Reddy Vemula
  • Patent number: 10811963
    Abstract: A multi-stage charge pump circuit including a first stage of the multi-stage charge pump having a first voltage output, a last stage of the multi-stage charge pump having a first voltage input, and an inter-stage limitation circuit configured to protect a voltage drop of the first voltage output of the first stage of the multi-stage charge pump when there is a voltage drop on the first voltage input of the last stage of the multi-stage charge pump.
    Type: Grant
    Filed: October 26, 2018
    Date of Patent: October 20, 2020
    Assignee: NXP B.V.
    Inventors: Xiaoqun Liu, Madan Mohan Reddy Vemula
  • Publication number: 20200161986
    Abstract: A low voltage drop rectifier is provided. The rectifier includes a diode having a first terminal coupled at an input node and a second terminal coupled at an output node. A first transistor having a first current electrode is coupled at the input node and a second current electrode is coupled at the output node. A comparator having a first input is coupled at the input node, a second input is coupled at the output node, and an output is coupled to a control electrode of the first transistor. A bias circuit is coupled to the comparator circuit and is configured to generate a bias current in the comparator.
    Type: Application
    Filed: November 16, 2018
    Publication date: May 21, 2020
    Inventors: Xueyang Geng, Madan Mohan Reddy Vemula, Alma Anderson
  • Publication number: 20200136502
    Abstract: A multi-stage charge pump including a first stage configured to generate a first output voltage, a last stage configured to receive the first output voltage from the first stage and output a second output voltage, a switch configured to receive the second output voltage from the last stage, and a voltage regulator circuit configured to control the second output voltage of the last stage to maintain a substantially constant on-resistance of the switch.
    Type: Application
    Filed: October 26, 2018
    Publication date: April 30, 2020
    Inventors: Xiaoqun LIU, Madan Mohan Reddy VEMULA
  • Publication number: 20200136503
    Abstract: A multi-stage charge pump circuit including a first stage of the multi-stage charge pump having a first voltage output, a last stage of the multi-stage charge pump having a first voltage input, and an inter-stage limitation circuit configured to protect a voltage drop of the first voltage output of the first stage of the multi-stage charge pump when there is a voltage drop on the first voltage input of the last stage of the multi-stage charge pump.
    Type: Application
    Filed: October 26, 2018
    Publication date: April 30, 2020
    Inventors: Xiaoqun LIU, Madan Mohan Reddy VEMULA
  • Publication number: 20200136601
    Abstract: A power switch over current protection system including a power switch transistor configured to deliver a power current from a power source to power load, a power switch driver configured to control and on/off state of the power switch, an over current protection (OCP) circuit to detect a threshold value of the power current, a discharge transistor configured to discharge a parasitic capacitance of the power switch transistor, and a system state machine to receive a signal from the OCP circuit configured to control an action of the power switch driver and discharge transistor depending on the level of the power current.
    Type: Application
    Filed: October 25, 2018
    Publication date: April 30, 2020
    Inventors: Xiaoqun LIU, Madan Mohan Reddy VEMULA
  • Patent number: 10209730
    Abstract: Low power solutions can be provided in a serial bus system with a logic controller circuit. The logic controller circuit can include analog circuitry that includes a plurality of analog components and trimming circuitry for configuring the analog components. Digital circuitry can be configured to switch between an active mode and a hibernation mode, wherein the hibernation mode consumes less current than the active mode. A voltage regulator circuit can be configured to generate a regulated voltage from a supply voltage. A reset generation circuit can be configured to determine that the supply voltage has reached a first threshold voltage level and enable the voltage regulator circuit. When the regulated voltage has reached a second threshold voltage level and the supply voltage has reached a third threshold voltage level, the digital circuitry can be switched to the active mode.
    Type: Grant
    Filed: November 23, 2017
    Date of Patent: February 19, 2019
    Assignee: NXP B.V.
    Inventors: Chiahung Su, Madan Mohan Reddy Vemula, Abjijeet Chandrakant Kulkarni, Kenneth Jaramillo, Siamak Delshadpour, Xueyang Geng
  • Patent number: 10152448
    Abstract: Embodiments of a resistor module of a USB interface device and a method for operating a resistor module of a USB interface device are described. In an embodiment, a resistor module of a USB interface device includes a pull-down resistor connectable to a USB power-sourcing device, a switch connected between the pull-down resistor and a fixed reference voltage, an energy storage unit connectable to the USB power-sourcing device and configured to store electrical energy in response to a current from the USB power-sourcing device, a switch control unit connected to the energy storage unit and configured to control the switch with a control signal in response to a voltage of the energy storage unit, and a glitch filter connected to the switch and to the switch control unit and configured to remove a glitch in the control signal. Other embodiments are also described.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: December 11, 2018
    Assignee: NXP B.V.
    Inventor: Madan Mohan Reddy Vemula
  • Patent number: 10088884
    Abstract: A protocol can specifie a power-sourcing voltage range that indicates power sourcing capabilities. Additional power sourcing capabilities can be communicated using voltage variations within the power-sourcing voltage range. A power-sourcing device can provide power to an external power-sinking device over a wired connection containing a plurality of wires. A voltage control circuit can be configured to drive a voltage over a wire of the plurality of wires. Processing circuitry can communicate, using the voltage control circuit, first power-sourcing capabilities to the external power-sinking device by setting the voltage over the wire to a value within the power-sourcing voltage range. The processing circuitry can also communicate, using the voltage control circuit, the additional power sourcing capabilities of the power-sourcing device using voltage variations on the wire, the voltage variations maintaining voltage on the wire within the power-sourcing voltage range.
    Type: Grant
    Filed: October 23, 2015
    Date of Patent: October 2, 2018
    Assignee: NXP B.V.
    Inventors: Kenneth Jaramillo, Madan Mohan Reddy Vemula, Sharad Murari, Abhijeet Chandrakant Kulkarni, Krishnan Tiruchi Natarajan
  • Patent number: 10019386
    Abstract: One or more characteristics of devices are ascertained in accordance with one or more aspects of the disclosure. As may be consistent with one or more embodiments, the attachment of an external circuit to an input port is detected based on a resistance value presented by the external circuit. A resistance range that includes the resistance value presented at the input port is determined, in response to detecting the attachment, by dynamically coupling one or more of a plurality of resistor-based circuits relative to the input port. A signal presented by the external circuit on the input port is coded based on the determined resistance range, using one or more of the resistor-based circuits, and the code is used to identify a type of the external circuit. These aspects can provide for the communication of power and data with a variety of different types of external circuits.
    Type: Grant
    Filed: May 6, 2015
    Date of Patent: July 10, 2018
    Assignee: NXP B.V.
    Inventors: Chiahung Su, Madan Mohan Reddy Vemula
  • Publication number: 20180183233
    Abstract: Embodiments of an electrostatic discharge (ESD) protection device and a method of operating an ESD protection device are described. In one embodiment, the ESD protection circuit is connected between a VDD rail and a VSS rail and includes an internal floating ESD rail located between the VDD rail and the VSS rail, I/O pins connected between the internal floating ESD rail and the VSS rail, ESD diodes corresponding to at least one I/O pin, an internal bias cell corresponding to an I/O pin and configured to short the corresponding I/O pin to the internal floating ESD rail when the I/O pin is pulled high, and an internal bias cell corresponding to a VDD pin of the VDD rail and configured to short the VDD rail to the internal floating ESD rail when the VDD pin is pulled high.
    Type: Application
    Filed: December 23, 2016
    Publication date: June 28, 2018
    Applicant: NXP B.V.
    Inventors: Gijs Jan de Raad, Madan Mohan Reddy Vemula
  • Publication number: 20180152183
    Abstract: Embodiments of a resistor module of a USB interface device and a method for operating a resistor module of a USB interface device are described. In an embodiment, a resistor module of a USB interface device includes a pull-down resistor connectable to a USB power-sourcing device, a switch connected between the pull-down resistor and a fixed reference voltage, an energy storage unit connectable to the USB power-sourcing device and configured to store electrical energy in response to a current from the USB power-sourcing device, a switch control unit connected to the energy storage unit and configured to control the switch with a control signal in response to a voltage of the energy storage unit, and a glitch filter connected to the switch and to the switch control unit and configured to remove a glitch in the control signal. Other embodiments are also described.
    Type: Application
    Filed: November 29, 2016
    Publication date: May 31, 2018
    Applicant: NXP B.V.
    Inventor: Madan Mohan Reddy Vemula
  • Publication number: 20180095490
    Abstract: Low power solutions can be provided in a serial bus system with a logic controller circuit. The logic controller circuit can include analog circuitry that includes a plurality of analog components and trimming circuitry for configuring the analog components. Digital circuitry can be configured to switch between an active mode and a hibernation mode, wherein the hibernation mode consumes less current than the active mode. A voltage regulator circuit can be configured to generate a regulated voltage from a supply voltage. A reset generation circuit can be configured to determine that the supply voltage has reached a first threshold voltage level and enable the voltage regulator circuit. When the regulated voltage has reached a second threshold voltage level and the supply voltage has reached a third threshold voltage level, the digital circuitry can be switched to the active mode.
    Type: Application
    Filed: November 23, 2017
    Publication date: April 5, 2018
    Inventors: Chiahung Su, Madan Mohan Reddy Vemula, Abjijeet Chandrakant Kulkarni, Kenneth Jaramillo, Siamak Delshadpour, Xueyang Geng
  • Publication number: 20170192446
    Abstract: Low power solutions can be provided in a serial bus system with a logic controller circuit. The logic controller circuit can include analog circuitry that includes a plurality of analog components and trimming circuitry for configuring the analog components. Digital circuitry can be configured to switch between an active mode and a hibernation mode, wherein the hibernation mode consumes less current than the active mode. A voltage regulator circuit can be configured to generate a regulated voltage from a supply voltage. A reset generation circuit can be configured to determine that the supply voltage has reached a first threshold voltage level and enable the voltage regulator circuit. When the regulated voltage has reached a second threshold voltage level and the supply voltage has reached a third threshold voltage level, the digital circuitry can be switched to the active mode.
    Type: Application
    Filed: January 6, 2016
    Publication date: July 6, 2017
    Inventors: Chiahung Su, Madan Mohan Reddy Vemula, Abhijeet Chandrakant Kulkarni, Kenneth Jaramillo
  • Patent number: 9698786
    Abstract: Aspects of the present disclosure are directed to detecting and powering external circuits via a common port. As may be implemented in accordance with one or more embodiments, an accessory detection circuit detects a type of an external circuit based upon a pull-down resistance at an interface port (e.g., where each accessory type provides a discernable pull-down resistance). Power switching circuitry couples power between the interface port and an internal power-based circuit, and operates in an open condition when the accessory detection circuit is active. An adaptive biasing circuit sets a voltage across the power switching circuitry to about zero, based on a voltage level provided on the interface port, thereby mitigating changes in the pull-down resistance due to current leakage. Once the type of external circuit is identified, the power switching circuitry couples power between the external circuit and the internal circuit.
    Type: Grant
    Filed: May 29, 2015
    Date of Patent: July 4, 2017
    Assignee: Nexperia B.V.
    Inventors: Madan Mohan Reddy Vemula, Harold Hanson
  • Publication number: 20170115711
    Abstract: A protocol can specifie a power-sourcing voltage range that indicates power sourcing capabilities. Additional power sourcing capabilities can be communicated using voltage variations within the power-sourcing voltage range. A power-sourcing device can provide power to an external power-sinking device over a wired connection containing a plurality of wires. A voltage control circuit can be configured to drive a voltage over a wire of the plurality of wires. Processing circuitry can communicate, using the voltage control circuit, first power-sourcing capabilities to the external power-sinking device by setting the voltage over the wire to a value within the power-sourcing voltage range. The processing circuitry can also communicate, using the voltage control circuit, the additional power sourcing capabilities of the power-sourcing device using voltage variations on the wire, the voltage variations maintaining voltage on the wire within the power-sourcing voltage range.
    Type: Application
    Filed: October 23, 2015
    Publication date: April 27, 2017
    Inventors: Kenneth Jaramillo, Madan Mohan Reddy Vemula, Sharad Murari, Abhijeet Chandrakant Kulkarni, Krishnan Tiruchi Natarajan
  • Publication number: 20160352323
    Abstract: Aspects of the present disclosure are directed to detecting and powering external circuits via a common port. As may be implemented in accordance with one or more embodiments, an accessory detection circuit detects a type of an external circuit based upon a pull-down resistance at an interface port (e.g., where each accessory type provides a discernable pull-down resistance). Power switching circuitry couples power between the interface port and an internal power-based circuit, and operates in an open condition when the accessory detection circuit is active. An adaptive biasing circuit sets a voltage across the power switching circuitry to about zero, based on a voltage level provided on the interface port, thereby mitigating changes in the pull-down resistance due to current leakage. Once the type of external circuit is identified, the power switching circuity couples power between the external circuit and the internal circuit.
    Type: Application
    Filed: May 29, 2015
    Publication date: December 1, 2016
    Inventors: Madan Mohan Reddy Vemula, Harold Hanson
  • Publication number: 20160328337
    Abstract: One or more characteristics of devices are ascertained in accordance with one or more aspects of the disclosure. As may be consistent with one or more embodiments, the attachment of an external circuit to an input port is detected based on a resistance value presented by the external circuit. A resistance range that includes the resistance value presented at the input port is determined, in response to detecting the attachment, by dynamically coupling one or more of a plurality of resistor-based circuits relative to the input port. A signal presented by the external circuit on the input port is coded based on the determined resistance range, using one or more of the resistor-based circuits, and the code is used to identify a type of the external circuit. These aspects can provide for the communication of power and data with a variety of different types of external circuits.
    Type: Application
    Filed: May 6, 2015
    Publication date: November 10, 2016
    Inventors: Chiahung Su, Madan Mohan Reddy Vemula