Patents by Inventor Madjid Hafizi

Madjid Hafizi 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: 10191526
    Abstract: A transmit driver is configured to operate under distinct supply voltage provided at output differential terminals. The transmit driver includes differential input transistors, first and second pairs of over-voltage protection differential transistors, and a current source coupled in series between the output terminals and a lower voltage rail. The transmit driver includes a first bias voltage generator configured to generate a first bias voltage based on the supply voltage across the output differential terminals. The first bias voltage is applied to the control terminals of the first pair of over-voltage protection transistors. The transmit driver includes a second bias generator for generating a second (substantially fixed) bias voltage for the control terminals of the second pair of over-voltage protection transistors. The transmit driver may be configured to operate based on a 3.3V supply voltage provided by an HDMI sink, or based on a 1.8V supply voltage provided by a bridge chip.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: January 29, 2019
    Assignee: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Chiu Keung Tang
  • Patent number: 10057090
    Abstract: A transmit driver or transmitter is provided to generate an output data signal based on different input modes, such as low speed (LS), full speed (FS), high speed (HS), and high speed interconnect (HSIC) modes of a Universal Serial Bus (USB) standard. The transmit driver includes a rail voltage generator for generating a rail voltage for a set of transmit driver slices based on the selected mode. The transmit driver includes a bias voltage generator for generating a bias voltage based on the selected mode for protecting transistors in the transmit driver slices from over-voltage stress. The transmit driver includes a predriver and level shifter for generating input signals for the transmit driver slices to set the output impedance of the transmit driver and the slew rate of the output data signal. The transmit driver includes an emphasis equalizer for providing controllable emphasis equalization to the output data signal.
    Type: Grant
    Filed: September 26, 2016
    Date of Patent: August 21, 2018
    Assignee: QUALCOMM Incorporated
    Inventor: Madjid Hafizi
  • Publication number: 20180129256
    Abstract: A transmit driver is configured to operate under distinct supply voltage provided at output differential terminals. The transmit driver includes differential input transistors, first and second pairs of over-voltage protection differential transistors, and a current source coupled in series between the output terminals and a lower voltage rail. The transmit driver includes a first bias voltage generator configured to generate a first bias voltage based on the supply voltage across the output differential terminals. The first bias voltage is applied to the control terminals of the first pair of over-voltage protection transistors. The transmit driver includes a second bias generator for generating a second (substantially fixed) bias voltage for the control terminals of the second pair of over-voltage protection transistors. The transmit driver may be configured to operate based on a 3.3V supply voltage provided by an HDMI sink, or based on a 1.8V supply voltage provided by a bridge chip.
    Type: Application
    Filed: November 8, 2016
    Publication date: May 10, 2018
    Inventors: Madjid Hafizi, Chiu Keung Tang
  • Publication number: 20180091333
    Abstract: A transmit driver or transmitter is provided to generate an output data signal based on different input modes, such as low speed (LS), full speed (FS), high speed (HS), and high speed interconnect (HSIC) modes of a Universal Serial Bus (USB) standard. The transmit driver includes a rail voltage generator for generating a rail voltage for a set of transmit driver slices based on the selected mode. The transmit driver includes a bias voltage generator for generating a bias voltage based on the selected mode for protecting transistors in the transmit driver slices from over-voltage stress. The transmit driver includes a predriver and level shifter for generating input signals for the transmit driver slices to set the output impedance of the transmit driver and the slew rate of the output data signal. The transmit driver includes an emphasis equalizer for providing controllable emphasis equalization to the output data signal.
    Type: Application
    Filed: September 26, 2016
    Publication date: March 29, 2018
    Inventor: Madjid Hafizi
  • Patent number: 9843324
    Abstract: A voltage-mode transmitter includes a calibration circuit having a replica circuit. By adjusting a feedback voltage driving a gate of a replica transistor in the replica circuit so that an impedance of the replica circuit matches an impedance of a variable resistor, the calibration circuit calibrates an output impedance of a single slice driver.
    Type: Grant
    Filed: November 10, 2016
    Date of Patent: December 12, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, George Shing
  • Publication number: 20170322582
    Abstract: A pre-driver circuit generates a driver bias signal based on a swing command, a driver impedance characteristic, and an input signal. A driver receives the driver bias signal and generates, in response, a driver signal having a swing and having an output impedance corresponding to the bias signal. Optionally, the driver receives power from a switchable one of multiple supply rails, according to the swing. Optionally, the driver has voltage controlled resistor elements and the driver bias signal is generated based on the swing command and a replica of the driver voltage controlled resistor elements.
    Type: Application
    Filed: July 24, 2017
    Publication date: November 9, 2017
    Inventors: Madjid Hafizi, Jie Xu, Xiaohua Kong, Nam V. Dang
  • Patent number: 9753479
    Abstract: A pre-driver circuit generates a driver bias signal based on a swing command, a driver impedance characteristic, and an input signal. A driver receives the driver bias signal and generates, in response, a driver signal having a swing and having an output impedance corresponding to the bias signal. Optionally, the driver receives power from a switchable one of multiple supply rails, according to the swing. Optionally, the driver has voltage controlled resistor elements and the driver bias signal is generated based on the swing command and a replica of the driver voltage controlled resistor elements.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: September 5, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Jie Xu, Xiaohua Kong, Nam V. Dang
  • Patent number: 9264263
    Abstract: A driver circuit for transmitting serial data on a communication link combines voltage-mode and current-mode drivers. The driver circuit uses a voltage-mode driver as the main output driver. One or more auxiliary current-mode drivers are connected in parallel with the voltage-mode driver to adjust the output signal by injecting currents into the outputs. The voltage-mode driver supplies most of the output drive. Thus, the output driver circuit can provide the power efficiency benefits associated with voltage-mode drivers. The current-mode drivers can provide, for example, pre-emphasis, level adjustment, skew compensation, and other modifications of the output signals. Thus, the driver circuit can also provide the signal adjustment abilities associated with current-mode drivers.
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: February 16, 2016
    Assignee: Qualcomm Incorporated
    Inventors: Madjid Hafizi, Xiaohua Kong, Zhi Zhu, Miao Li
  • Patent number: 9195254
    Abstract: A distribution current is split into a first control current, a second control current, and a third control current, in an apportionment according to a distribution command. A first control voltage is generated in response to the third control current. A second control voltage is generated as indication of the first control current, and a third control voltage is generated as indication of the second control current. Optionally, de-emphasis contribution of a first driver, a second driver and a third driver to an output is controlled based, at least in part, on the first control voltage, the second control voltage and the third control voltage, respectively.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: November 24, 2015
    Assignee: QUALCOMM, Incorporated
    Inventors: Miao Li, Madjid Hafizi, Xiaohua Kong
  • Publication number: 20150304134
    Abstract: A driver circuit for transmitting serial data on a communication link combines voltage-mode and current-mode drivers. The driver circuit uses a voltage-mode driver as the main output driver. One or more auxiliary current-mode drivers are connected in parallel with the voltage-mode driver to adjust the output signal by injecting currents into the outputs. The voltage-mode driver supplies most of the output drive. Thus, the output driver circuit can provide the power efficiency benefits associated with voltage-mode drivers. The current-mode drivers can provide, for example, pre-emphasis, level adjustment, skew compensation, and other modifications of the output signals. Thus, the driver circuit can also provide the signal adjustment abilities associated with current-mode drivers.
    Type: Application
    Filed: April 21, 2014
    Publication date: October 22, 2015
    Applicant: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Xiaohua Kong, Zhi Zhu, Miao Li
  • Patent number: 8896353
    Abstract: A population of drivers is provided in parallel to a driver output and a population of pre-emphasis path drivers is provided in parallel to the driver output. The population of drivers is updated and the population of pre-emphasis path drivers is updated in an inverse relation to the updating of the population of pre-emphasis path drivers. Optionally, the population of drivers has an initial value of n and the population of pre-emphasis path drivers has an initial value of m, and the sum of n and m is P. Optionally, the updated population of n is n? and the updated population of m is m?, and n? is approximately equal to P?m?.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: November 25, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Jie Xu
  • Publication number: 20140176196
    Abstract: A distribution current is split into a first control current, a second control current, and a third control current, in an apportionment according to a distribution command. A first control voltage is generated in response to the third control current. A second control voltage is generated as indication of the first control current, and a third control voltage is generated as indication of the second control current. Optionally, de-emphasis contribution of a first driver, a second driver and a third driver to an output is controlled based, at least in part, on the first control voltage, the second control voltage and the third control voltage, respectively.
    Type: Application
    Filed: December 21, 2012
    Publication date: June 26, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Miao Li, Madjid Hafizi, Xiaohua Kong
  • Publication number: 20140035549
    Abstract: A pre-driver circuit generates a driver bias signal based on a swing command, a driver impedance characteristic, and an input signal. A driver receives the driver bias signal and generates, in response, a driver signal having a swing and having an output impedance corresponding to the bias signal. Optionally, the driver receives power from a switchable one of multiple supply rails, according to the swing. Optionally, the driver has voltage controlled resistor elements and the driver bias signal is generated based on the swing command and a replica of the driver voltage controlled resistor elements.
    Type: Application
    Filed: August 1, 2012
    Publication date: February 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Jie Xu, Xiaohua Kong, Nam V. Dang
  • Publication number: 20140035625
    Abstract: A population of drivers is provided in parallel to a driver output and a population of pre-emphasis path drivers is provided in parallel to the driver output. The population of drivers is updated and the population of pre-emphasis path drivers is updated in an inverse relation to the updating of the population of pre-emphasis path drivers. Optionally, the population of drivers has an initial value of n and the population of pre-emphasis path drivers has an initial value of m, and the sum of n and m is P. Optionally, the updated population of n is n? and the updated population of m is m?, and n? is approximately equal to P?m?.
    Type: Application
    Filed: August 1, 2012
    Publication date: February 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Madjid Hafizi, Jie Xu
  • Patent number: 8081947
    Abstract: Aspects of a method and system for configurable Active/Passive Mixer and Shared GM Stage may include configuring an RF mixer in frequency demodulator to operate in an active mode or a passive mode. An in-phase (I) processing path and a quadrature (Q) processing path of the RF mixer may utilize a single shared GM stage. One or more switches may be activated to enable the active mode or the passive mode of operation for the RF mixer.
    Type: Grant
    Filed: December 31, 2006
    Date of Patent: December 20, 2011
    Assignee: Broadcom Corporation
    Inventors: Adedayo Ojo, Madjid Hafizi, Arya Behzad
  • Patent number: 8023591
    Abstract: Aspects of a method and system for a shared GM-stage between in-phase and quadrature channels may include processing an in-phase (I) component signal for the I channel and a quadrature (Q) component signal for the Q channel via one or more shared transconductance stages in a frequency demodulator. The I channel may be isolated from the Q channel and the Q channel may be isolated from the I channel using isolation resistors. The values of the isolation resistors may be selected so as to balance the isolation and signal attenuation. A folding circuit, comprising active devices, may isolate the I channel from the Q channel. A generated voltage may be utilized to bias the folding circuit. An oscillator for the I channel may be isolated from a mixer for the Q channel and an oscillator for the Q channel may be isolated from a mixer for the I channel.
    Type: Grant
    Filed: December 31, 2006
    Date of Patent: September 20, 2011
    Assignee: Broadcom Corporation
    Inventor: Madjid Hafizi
  • Publication number: 20080139159
    Abstract: Aspects of a method and system for configurable Active/Passive Mixer and Shared GM Stage may include configuring an RF mixer in frequency demodulator to operate in an active mode or a passive mode. An in-phase (I) processing path and a quadrature (Q) processing path of the RF mixer may utilize a single shared GM stage.
    Type: Application
    Filed: December 31, 2006
    Publication date: June 12, 2008
    Inventors: Adedayo Ojo, Madjid Hafizi, Arya Behzad
  • Publication number: 20080139162
    Abstract: Aspects of a method and system for a shared GM-stage between in-phase and quadrature channels may include processing an in-phase (I) component signal for the I channel and a quadrature (Q) component signal for the Q channel via one or more shared transconductance stages in a frequency demodulator. The I channel may be isolated from the Q channel and the Q channel may be isolated from the I channel using isolation resistors. The values of the isolation resistors may be selected so as to balance the isolation and signal attenuation. A folding circuit, comprising active devices, may isolate the I channel from the Q channel. A generated voltage may be utilized to bias the folding circuit. An oscillator for the I channel may be isolated from a mixer for the Q channel and an oscillator for the Q channel may be isolated from a mixer for the I channel.
    Type: Application
    Filed: December 31, 2006
    Publication date: June 12, 2008
    Inventor: Madjid Hafizi
  • Publication number: 20060068746
    Abstract: An integrated circuit includes an RF receiver has a direct-conversion down-converter and demodulator architecture with an integrated low noise amplifier (LNA) for operation in a frequency band of interest (cellular) and provisions for an off-chip LNA for operation in a second (higher) frequency band of interest (such as PCS). A baseband processor includes high-dynamic variable gain amplifiers and 7th-order elliptic low-pass filters. The IC also includes a 4 GHz PLL frequency synthesizer and a three wire series interface to external digital baseband circuits, such as a digital signal processor.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Inventors: Shen Feng, Madjid Hafizi, Qizheng Gu, Robert Ruth, Richard Schwab, Taoling Fu, Kim Schulze, Per Karlsen
  • Patent number: 5920773
    Abstract: An integrated circuit technology combines heterojunction bipolar transistors (HBTs), high electron mobility transistors (HEMTs) and other components along with interconnect metallization on a single substrate. In a preferred embodiment a flat substrate is patterned, using dry etching, to provide one or more mesas in locations which will eventually support HEMTs. A device stack including HEMT and HBT layers is built up over the substrate by molecular beam epitaxy, with the active HEMT devices located on the mesas within openings in the HBT layer. In this way the active HEMT is aligned with the HBT layer to planarize the finished integrated circuit.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: July 6, 1999
    Assignee: Hughes Electronics Corporation
    Inventors: Madjid Hafizi, Julia J. Brown, William E. Stanchina