Patents by Inventor Freeman Zhong

Freeman Zhong 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: 8848774
    Abstract: A method and system of adaptation of a linear equalizer using a virtual decision feedback equalizer (VDFE) are disclosed. In one embodiment, a method of adjusting a setting of a linear equalizer includes determining a change to a decision feedback equalizer (DFE) tap weight value of a predefined metric according to a data signal and an error signal (e.g., the change may be generated according to an average of a specified plurality of data signals and the error signal); using the change in the DFE tap weight value to algorithmically generate a modification in a linear equalizer setting; and adjusting the linear equalizer setting. The linear equalizer is located in a feed-forward path and/or a feedback path of data transmission. The linear equalizer may be located in a transmitter and/or a receiver. The linear equalizer may be a continuous time linear equalizer and/or a Finite Impulse Response (FIR) linear equalizer.
    Type: Grant
    Filed: August 19, 2008
    Date of Patent: September 30, 2014
    Assignee: LSI Corporation
    Inventors: Lizhi Zhong, Cathy Ye Liu, Amaresh Virupanagouda Malipatil, Freeman Zhong
  • Patent number: 8437388
    Abstract: Data latch circuit and method of low power decision feedback equalization (DFE) system is disclosed. In one embodiment, the data latch circuit of the of a decision feedback equalization (DFE) system includes a first parallel n-channel metal-oxide-semiconductor field-effect transistor (NMOS) pair to input a differential input voltage. The data latch circuit also includes a second parallel NMOS pair coupled to the first parallel NMOS pair to input a decision feedback equalization (DFE) voltage. The data latch circuit further includes a cross-coupled PMOS pair to generate a positive feedback to the first parallel NMOS pair and/or the second parallel NMOS pair. In addition, the data latch circuit includes a cross-coupled NMOS pair to escalate the positive feedback. Furthermore the data latch circuit includes a latching circuit to generate a signal data based on the sinking of a current at an input of the latching circuit and/or the positive feedback.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: May 7, 2013
    Assignee: LSI Corporation
    Inventors: Yi Zeng, Freeman Zhong, Peter Windler
  • Publication number: 20110286511
    Abstract: Data latch circuit and method of low power decision feedback equalization (DFE) system is disclosed. In one embodiment, the data latch circuit of the of a decision feedback equalization (DFE) system includes a first parallel n-channel metal-oxide-semiconductor field-effect transistor (NMOS) pair to input a differential input voltage. The data latch circuit also includes a second parallel NMOS pair coupled to the first parallel NMOS pair to input a decision feedback equalization (DFE) voltage. The data latch circuit further includes a cross-coupled PMOS pair to generate a positive feedback to the first parallel NMOS pair and/or the second parallel NMOS pair. In addition, the data latch circuit includes a cross-coupled NMOS pair to escalate the positive feedback. Furthermore the data latch circuit includes a latching circuit to generate a signal data based on the sinking of a current at an input of the latching circuit and/or the positive feedback.
    Type: Application
    Filed: November 19, 2010
    Publication date: November 24, 2011
    Applicant: LSI Corporation
    Inventors: YI ZENG, Freeman Zhong, Peter Windler
  • Patent number: 7940140
    Abstract: The present invention is a self-calibrating, dual-band, wide range LC tank Voltage Controlled Oscillator (VCO) system. The system may include a first Voltage-Controlled Oscillator (VCO) and a second Voltage-Controlled Oscillator (VCO). The system may further include a calibration engine. The calibration engine may be configured for being connectable to at least one of the first VCO or the second VCO. The calibration engine may further be configured for automatically establishing/providing a VCO fix capacitor band code setting and a gear control setting for selectively activating or inactivating the first VCO and/or the second VCO. The calibration engine may be further configured for automatically comparing a VCO control voltage of the system to an allowable control voltage range for the system and may be further configured for automatically adjusting the VCO fix capacitor band code setting and/or the gear control setting when the VCO control voltage falls outside of the allowable control voltage range.
    Type: Grant
    Filed: June 3, 2008
    Date of Patent: May 10, 2011
    Assignee: LSI Corporation
    Inventors: Yi Zeng, Freeman Zhong
  • Patent number: 7869498
    Abstract: Low power decision feedback equalization (DFE) through applying DFE data to input data in a data latch is disclosed. In one embodiment, a decision feedback equalization (DFE) system to remove a post cursor intersymbol interference (ISI) through feeding back previous data scaled with adaptive weights to the DFE system, with each slice of the DFE system may include a first set of decision feedback digital to analog converters (DACs) to generate a first DFE data obtained through the feeding back the previous data scaled with the adaptive weights and a first data latch to generate an output data of the each slice through applying the first DFE data to an input data of the each slice in the first data latch to remove a first delay caused by performing the applying the first DFE data to the input data of the each slice outside of the first data latch.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: January 11, 2011
    Assignee: LSI Corporation
    Inventors: Yi Zeng, Freeman Zhong, Peter Windler
  • Patent number: 7688928
    Abstract: In one embodiment a control unit of a communication system exchanging a multiple-phase time-interleaved data includes a first Phase-Locked Loop (PLL) to generate a set of un-calibrated multiple-phase signals of a first-clock; a second-PLL, a pulse generator, a pulse-width measurement unit and a phase calibration engine to evaluate adjustments required in a temporal location of a logically critical voltage transition edge in each signal in the un-calibrated set; and a phase adjustment unit to adjust the temporal location of the logically critical voltage transition edge in each signal in the un-calibrated set to generate a set of calibrated multiple-phase signals of the first-clock such that each signal in the calibrated set includes the logically critical voltage transition edge which is time skewed in a predetermined amount from the logically critical voltage transition edge in other signals in the same set within a predetermined accuracy.
    Type: Grant
    Filed: September 5, 2006
    Date of Patent: March 30, 2010
    Assignee: LSI Corporation
    Inventors: Cathy Ye Lin, Freeman Zhong, Catherine Chow, Yi Zeng, Ryan Park
  • Publication number: 20100046598
    Abstract: A method and system of adaptation of a linear equalizer using a virtual decision feedback equalizer (VDFE) are disclosed. In one embodiment, a method of adjusting a setting of a linear equalizer includes determining a change to a decision feedback equalizer (DFE) tap weight value of a predefined metric according to a data signal and an error signal (e.g., the change may be generated according to an average of a specified plurality of data signals and the error signal); using the change in the DFE tap weight value to algorithmically generate a modification in a linear equalizer setting; and adjusting the linear equalizer setting. The linear equalizer is located in a feed-forward path and/or a feedback path of data transmission. The linear equalizer may be located in a transmitter and/or a receiver. The linear equalizer may be a continuous time linear equalizer and/or a Finite Impulse Response (FIR) linear equalizer.
    Type: Application
    Filed: August 19, 2008
    Publication date: February 25, 2010
    Inventors: LIZHI ZHONG, Cathy Ye Liu, Amaresh Virupanagouda Malipatil, Freeman Zhong
  • Publication number: 20090295488
    Abstract: The present invention is a self-calibrating, dual-band, wide range LC tank Voltage Controlled Oscillator (VCO) system. The system may include a first Voltage-Controlled Oscillator (VCO) and a second Voltage-Controlled Oscillator (VCO). The system may further include a calibration engine. The calibration engine may be configured for being connectable to at least one of the first VCO or the second VCO. The calibration engine may further be configured for automatically establishing/providing a VCO fix capacitor band code setting and a gear control setting for selectively activating or inactivating the first VCO and/or the second VCO. The calibration engine may be further configured for automatically comparing a VCO control voltage of the system to an allowable control voltage range for the system and may be further configured for automatically adjusting the VCO fix capacitor band code setting and/or the gear control setting when the VCO control voltage falls outside of the allowable control voltage range.
    Type: Application
    Filed: June 3, 2008
    Publication date: December 3, 2009
    Inventors: Yi Zeng, Freeman Zhong
  • Publication number: 20080198916
    Abstract: Low power decision feedback equalization (DFE) through applying DFE data to input data in a data latch is disclosed. In one embodiment, a decision feedback equalization (DFE) system to remove a post cursor intersymbol interference (ISI) through feeding back previous data scaled with adaptive weights to the DFE system, with each slice of the DFE system may include a first set of decision feedback digital to analog converters (DACs) to generate a first DFE data obtained through the feeding back the previous data scaled with the adaptive weights and a first data latch to generate an output data of the each slice through applying the first DFE data to an input data of the each slice in the first data latch to remove a first delay caused by performing the applying the first DFE data to the input data of the each slice outside of the first data latch.
    Type: Application
    Filed: February 21, 2007
    Publication date: August 21, 2008
    Inventors: Yi Zeng, Freeman Zhong, Peter Windler
  • Publication number: 20080070537
    Abstract: A method, apparatus and/or system of a duty cycle counting phase calibration scheme of an I/O interface is disclosed.
    Type: Application
    Filed: September 5, 2006
    Publication date: March 20, 2008
    Inventors: Cathy Ye Lin, Freeman Zhong, Catherine Chow, Yi Zeng, Ryan Park
  • Publication number: 20070139078
    Abstract: The improved PCML communications driver corrects current loss and reduced voltage swing when driving an LVDS receiver load by reducing the value of the Rt1 resistors. By changing the value of the two Rt1 resistors from Rt1 to Rt1/2 (or lower), the full bias current can be restored and voltage swing is substantially improved. By making Rt1 a programmable resistor so Rt=Rt1/2 for DC bias calculation, Q2 bias current is increased back to IB, instead of IB/2.
    Type: Application
    Filed: December 20, 2005
    Publication date: June 21, 2007
    Inventors: George Tang, Freeman Zhong
  • Patent number: 6005429
    Abstract: An apparatus for and method of reducing electromagnetic interference of an integrated circuit by providing multiple choking levels are disclosed. A choking circuit includes a choking level select signal generator, a pulse choking circuit connected to the choking level select signal generator, and a modulation control circuit connected to the pulse choking circuit. The choking level is increased when modules of the integrated circuit are less active, which reduces electromagnetic interference. The choking level is decreased when modules of the integrated circuit are more active, which maintains the voltage supplied to the power bus above a desired level.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: December 21, 1999
    Assignee: National Semiconductor Corporation
    Inventors: Freeman Zhong, William E. Miller