Patents by Inventor Ionut C. Cical

Ionut C. Cical 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: 11323108
    Abstract: A low current line termination circuit includes first and second input interfaces each configured to receive a Vreceive+ and a Vreceive? voltage, respectively. The circuit further includes a first diode connected transistor (“DCT”) coupled to the second input interface, a first switching transistor (“ST”) coupled to the first DCT and to the first input interface, and a first delay element coupled between one of the input interfaces and a gate of the first ST. The circuit further includes a second DCT coupled to the one of the two input interfaces, a second ST coupled to the second DCT and to the second input interface, and a second delay element coupled between another of the two input interfaces and a gate of the second ST.
    Type: Grant
    Filed: November 30, 2020
    Date of Patent: May 3, 2022
    Assignee: XILINX, INC.
    Inventors: Bob W. Verbruggen, Christophe Erdmann, Ionut C. Cical
  • Patent number: 11190178
    Abstract: Examples described herein provide an apparatus having a circuit with a grounding circuit and a switch. The apparatus generally includes a gate induced drain leakage (GIDL) protection circuit coupled to the switch and to an output voltage. The GIDL protection circuit may include a switch protection circuit configured to maintain a drain voltage of the switch less than a first supply voltage (Vdd) when the circuit is in an OFF state; and a ground protection circuit configured to maintain a drain voltage of the grounding circuit less than the first supply voltage when the circuit is in an ON state.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: November 30, 2021
    Assignee: XILINX, INC.
    Inventors: Diarmuid Collins, Edward Cullen, Ionut C. Cical
  • Patent number: 11181426
    Abstract: A temperature sensor includes a current source to produce a first bias current and a second bias current, a plurality of diodes, and temperature estimation circuitry. The plurality of diodes includes at least a first diode to receive the first bias current and a second diode to receive the second bias current. The temperature estimate circuitry measures a first voltage bias across the first diode resulting from the first bias current and a second voltage bias across the second diode resulting from the second bias current, and estimates a temperature of an environment of the temperature sensor based at least in part on the first voltage bias and the second voltage bias. The temperature sensor further includes error detection circuitry to measure at least one of the first or second bias currents and determine an amount of error in the temperature estimate based at least in part on the measurement.
    Type: Grant
    Filed: February 5, 2019
    Date of Patent: November 23, 2021
    Assignee: Xilinx, Inc.
    Inventors: Edward Cullen, Umanath R. Kamath, John K. Jennings, Diarmuid Collins, Ionut C. Cical
  • Patent number: 11003204
    Abstract: Examples described herein provide for a relaxation oscillator and corresponding methods of operation. In an example, a circuit includes a dynamically controllable current source, a capacitor, and an oscillator generation circuit. The dynamically controllable current source includes a digitally tunable current mirror configured to generate a current. The digitally tunable current mirror includes multiple transistors configured to be selectively electrically connected in parallel to alter a gain of the digitally tunable current mirror to control the current. The capacitor is selectively electrically connected to the dynamically controllable current source. The oscillator generation circuit is electrically connected to the capacitor. The oscillator generation circuit is configured to generate an oscillation signal in response to a voltage of the capacitor.
    Type: Grant
    Filed: December 11, 2018
    Date of Patent: May 11, 2021
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, Edward Cullen, Brendan Farley
  • Patent number: 10608630
    Abstract: A complementary metal-oxide-semiconductor (CMOS) switching system with increased supply rejection is disclosed. The system comprises a voltage regulator and a CMOS circuit. The voltage regulator receives a supply voltage and generates a regulated voltage by regulating an amplitude of the received supply voltage. The CMOS circuit includes an input terminal to receive a first voltage, switching circuitry to selectively couple the CMOS circuit to the voltage regulator in one of a plurality of configurations, and an output terminal to output a second voltage based at least in part on the first voltage and the regulated voltage when the CMOS circuit is coupled to the voltage regulator in a first configuration of the plurality of configurations.
    Type: Grant
    Filed: June 26, 2018
    Date of Patent: March 31, 2020
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, Diarmuid Collins, John K. Jennings
  • Patent number: 10505444
    Abstract: A voltage divider is described. The voltage divider comprises a pair of input nodes for receiving an input signal; a pair of output nodes configured to generate an output signal; a first capacitor having a first terminal coupled to a first output node of the pair of output nodes and a second terminal coupled to a second output node of the pair of output nodes; and a second capacitor having first terminal and a second terminal; a bypass switch having a first terminal coupled to the first terminal of the second capacitor and a second terminal coupled to the second terminal of the second capacitor; and a charge sharing switch coupled to the second terminal of the second capacitor; wherein the bypass switch and the charge sharing switch enable the sharing of charge between the first capacitor and the second capacitor.
    Type: Grant
    Filed: October 4, 2018
    Date of Patent: December 10, 2019
    Assignee: Xilinx, Inc.
    Inventors: Ionut C. Cical, Diarmuid Collins, Edward Cullen
  • Patent number: 10418994
    Abstract: A circuit for extending the bandwidth of a termination block is described. The circuit comprises an I/O contact configured to receive an input signal; and a termination circuit coupled to the I/O contact, wherein the termination circuit comprises a plurality of trim legs coupled between a power supply and the I/O contact, each trim leg having a switch to control the impedance in the trim leg.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: September 17, 2019
    Assignee: Xilinx, Inc.
    Inventors: Edward Cullen, Ionut C. Cical
  • Publication number: 20190172504
    Abstract: An example voltage reference circuit includes: a reference circuit comprising a first circuit configured to generate a proportional-to-temperature current and corresponding first control voltage and a second circuit configured to generate a complementary-to-temperature current and corresponding second control voltage; a first current source coupled to a first load circuit, the first current source generating a sum current of the proportional-to-temperature current and the complementary-to-temperature current in response to the first and second control voltages, the first load circuit generating a zero temperature coefficient (Tempco) voltage from the sum current; and a second current source coupled to a second load circuit, the second current source generating the sum current of the proportional-to-temperature current and the complementary-to-temperature current in response to the first and second control voltages, the second load circuit generating a negative Tempco voltage from the sum current and the compl
    Type: Application
    Filed: December 5, 2017
    Publication date: June 6, 2019
    Applicant: Xilinx, Inc.
    Inventors: Umanath R. Kamath, John K. Jennings, Edward Cullen, Ionut C. Cical, Darragh Walsh
  • Patent number: 10290330
    Abstract: An example voltage reference circuit includes: a reference circuit comprising a first circuit configured to generate a proportional-to-temperature current and corresponding first control voltage and a second circuit configured to generate a complementary-to-temperature current and corresponding second control voltage; a first current source coupled to a first load circuit, the first current source generating a sum current of the proportional-to-temperature current and the complementary-to-temperature current in response to the first and second control voltages, the first load circuit generating a zero temperature coefficient (Tempco) voltage from the sum current; and a second current source coupled to a second load circuit, the second current source generating the sum current of the proportional-to-temperature current and the complementary-to-temperature current in response to the first and second control voltages, the second load circuit generating a negative Tempco voltage from the sum current and the compl
    Type: Grant
    Filed: December 5, 2017
    Date of Patent: May 14, 2019
    Assignee: XILINX, INC.
    Inventors: Umanath R. Kamath, John K. Jennings, Edward Cullen, Ionut C. Cical, Darragh Walsh
  • Patent number: 10243526
    Abstract: A device may include a voltage-to-current converter circuit having an operational transconductance amplifier (OTA), the voltage-to-current converter circuit for generating a bias current that is proportional to a reference voltage at a reference voltage input port of the OTA, and a bias current feedback path for providing the bias current to a bias current input port of the OTA. The device may further include a startup current generator circuit coupled to the bias current input port of the OTA, the startup current generator circuit controllable to provide a startup current to the bias current input port during a startup of the device and to be deactivated after the startup of the device.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: March 26, 2019
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, John K. Jennings, Diarmuid Collins
  • Patent number: 10236873
    Abstract: In an example, an apparatus includes an analog switch having an n-type metal oxide semiconductor (NMOS) circuit in parallel with a p-type metal oxide semiconductor (PMOS) circuit between a switch input and a switch output. The analog switch is responsive to an enable signal that determines switch state thereof. The NMOS circuit includes a switch N-channel transistor coupled to a buffer N-channel transistor, a gate of the switch N-channel transistor coupled to the enable signal and a gate of the buffer N-channel transistor coupled to a modulated N-channel gate voltage. The PMOS circuit including a switch P-channel transistor coupled to a buffer P-channel transistor, a gate of the switch P-channel transistor coupled to a complement of the enable signal and a gate of the buffer P-channel transistor coupled to a modulated P-channel gate voltage.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: March 19, 2019
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, John K. Jennings, Chandrika Durbha
  • Patent number: 9935597
    Abstract: A circuit for receiving an input signal is described. The receiver comprises a first receiver input configured to receive a first input of a differential input signal; a second receiver input configured to receive a second input of a differential input signal; a differential pair having an inverting input and a non-inverting input; a first impedance matching element coupled to the differential pair, wherein the first impedance matching element provides DC impedance matching from the inverting input and non-inverting input of the differential pair; and a second impedance matching element coupled to the differential pair, wherein the second impedance matching element provides AC impedance matching from the inverting input and non-inverting input of the differential pair.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: April 3, 2018
    Assignee: XILINX, INC.
    Inventors: Christophe Erdmann, Diarmuid Collins, Edward Cullen, Ionut C. Cical
  • Publication number: 20170346455
    Abstract: A circuit for receiving an input signal is described. The receiver comprises a first receiver input configured to receive a first input of a differential input signal; a second receiver input configured to receive a second input of a differential input signal; a differential pair having an inverting input and a non-inverting input; a first impedance matching element coupled to the differential pair, wherein the first impedance matching element provides DC impedance matching from the inverting input and non-inverting input of the differential pair; and a second impedance matching element coupled to the differential pair, wherein the second impedance matching element provides AC impedance matching from the inverting input and non-inverting input of the differential pair.
    Type: Application
    Filed: May 27, 2016
    Publication date: November 30, 2017
    Applicant: Xilinx, Inc.
    Inventors: Christophe Erdmann, Diarmuid Collins, Edward Cullen, Ionut C. Cical
  • Patent number: 9503058
    Abstract: Various example implementations are directed to circuits and methods for generating a clock signal. According to an example embodiment, a circuit arrangement includes a relaxation oscillator configured to output a clock signal. The clock signal has an oscillation frequency dependent on a reference current provided to the relaxation oscillator, an operating temperature of the relaxation oscillator, and a supply voltage used to power the relaxation oscillator. The circuit arrangement also includes a current source coupled to the relaxation oscillator and configured to generate the reference current. The current source is configured to adjust the reference current, in response to a change in one or more of the temperature of the relaxation oscillator and the supply voltage, to inhibit change in the oscillation frequency of the clock signal.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: November 22, 2016
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, John K. Jennings, Edward Cullen
  • Publication number: 20160277019
    Abstract: In an example, an apparatus includes an analog switch having an n-type metal oxide semiconductor (NMOS) circuit in parallel with a p-type metal oxide semiconductor (PMOS) circuit between a switch input and a switch output. The analog switch is responsive to an enable signal that determines switch state thereof. The NMOS circuit includes a switch N-channel transistor coupled to a buffer N-channel transistor, a gate of the switch N-channel transistor coupled to the enable signal and a gate of the buffer N-channel transistor coupled to a modulated N-channel gate voltage. The PMOS circuit including a switch P-channel transistor coupled to a buffer P-channel transistor, a gate of the switch P-channel transistor coupled to a complement of the enable signal and a gate of the buffer P-channel transistor coupled to a modulated P-channel gate voltage.
    Type: Application
    Filed: March 17, 2015
    Publication date: September 22, 2016
    Applicant: Xilinx, Inc.
    Inventors: Ionut C. Cical, John K. Jennings, Chandrika Durbha
  • Patent number: 9377795
    Abstract: In an example, a temperature-corrected voltage reference circuit for use in an integrated circuit (IC) includes a voltage reference circuit, a programmable gain amplifier, and a digital control circuit. The programmable gain amplifier includes a first input coupled to the voltage reference circuit, a second input coupled to receive a control signal, and an output coupled to provide a temperature-corrected voltage reference. The digital control circuit includes an input coupled to receive a temperature signal indicative of temperature of the IC and an output coupled to the second input of the programmable gain amplifier, the digital control circuit generating the control signal in response to the temperature signal.
    Type: Grant
    Filed: November 17, 2014
    Date of Patent: June 28, 2016
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, Edward Cullen
  • Patent number: 9245886
    Abstract: Devices for isolating an input from an output are disclosed. For example, a device includes a first p-type metal oxide semiconductor transistor and a first circuit. A source of the first p-type metal oxide semiconductor transistor is connected to an input of the device. The first circuit is for delivering a signal on the input of the device to a gate of the first p-type metal oxide semiconductor transistor when an enable signal is deactivated and for delivering a ground voltage to the gate of the first p-type metal oxide semiconductor transistor when the enable signal is activated.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: January 26, 2016
    Assignee: XILINX, INC.
    Inventors: John K. Jennings, Ionut C. Cical
  • Patent number: 9184623
    Abstract: A circuit for implementing a charge/discharge switch in an integrated circuit is described. The circuit comprises a supply bias path coupled to a first node, wherein the supply bias path provides a charging bias current to the first node; a charge transistor connected between the first node and a first terminal of a capacitor; a charge switch coupled between the first node and a ground potential, wherein the charge switch enables charging of the capacitor by way of the first node; a discharge transistor connected between the first terminal of the capacitor and a second node; a discharge switch coupled between the second node and a reference voltage, wherein the discharge switch enables discharging of the capacitor by way of the second node; and a ground bias path coupled between the second node and ground, wherein the ground bias path provides a discharging bias current to the second node. A method of implementing a charge/discharge switch in an integrated circuit is also described.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: November 10, 2015
    Assignee: XILINX, INC.
    Inventors: Ionut C. Cical, John K. Jennings
  • Patent number: 9000800
    Abstract: A system for calibrating impedance of an input/output (I/O) buffer on a semiconductor die includes: the I/O buffer; a temperature sensor on the semiconductor die; and a supply sensor on the semiconductor die. The temperature sensor is configured to acquire temperature information for calibrating the I/O buffer. The supply sensor is configured to acquire voltage information for calibrating the I/O buffer. The I/O buffer comprises: a memory component coupled to the temperature and supply sensors and configured to store the acquired temperature or voltage information; a logic component coupled to the memory component; and a driver with driver legs. The driver is coupled to the logic component. The logic component is configured to generate driver control signals representing an on/off configuration for the driver legs of the driver based at least in part on the acquired temperature information or the acquired voltage information stored in the memory component.
    Type: Grant
    Filed: September 17, 2012
    Date of Patent: April 7, 2015
    Assignee: Xilinx, Inc.
    Inventors: Ionut C. Cical, Edward Cullen, Ivan Bogue
  • Publication number: 20150014779
    Abstract: Devices for isolating an input from an output are disclosed. For example, a device includes a first p-type metal oxide semiconductor transistor and a first circuit. A source of the first p-type metal oxide semiconductor transistor is connected to an input of the device. The first circuit is for delivering a signal on the input of the device to a gate of the first p-type metal oxide semiconductor transistor when an enable signal is deactivated and for delivering a ground voltage to the gate of the first p-type metal oxide semiconductor transistor when the enable signal is activated.
    Type: Application
    Filed: July 12, 2013
    Publication date: January 15, 2015
    Inventors: John K. Jennings, Ionut C. Cical