Patents by Inventor Longxing Shi

Longxing Shi 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).

  • Publication number: 20140002158
    Abstract: A high-speed fully differential clock duty cycle calibration circuit applied to calibrating the clock duty cycle in a high-speed system. The circuit detects the duty cycle with a continuous time integrator, and directly adjusts the duty cycle on a clock transmission link so as to increase the working speed. Being of a fully differential circuit structure, the circuit can calibrate the duty cycle under a designated process within a higher and wider frequency range, and has relatively good constraining force for process mismatch and common mode noise. The circuit comprises adjustment level ADJ1 and ADJ2, a first buffer level BUF1, a second buffer level BUF2 and a duty cycle detection level DCD.
    Type: Application
    Filed: August 18, 2011
    Publication date: January 2, 2014
    Applicant: SOUTHEAST UNIVERSITY
    Inventors: Longxing Shi, Danhong Gu, Junhui Gu, Jianhui Wu, Wei Zhao, Zhiyi Ye, Dahai Hu, Meng Zhang, Hong Li
  • Publication number: 20130300490
    Abstract: A return-type current-reuse mixer having a transconductance/amplification stage, a mixing stage, and a high-pass and a low-pass filter network. The transconductance/amplification stage has a current-reuse CMOS topology wherein an input frequency signal is converted into a frequency current, low-frequency components are removed from the frequency current by the high-pass filter network, the frequency current is fed into the mixing stage, modulation occurs in the mixing stage, and then an intermediate-frequency signal is generated and output. Once high-frequency components are removed from the intermediate-frequency signal by the low-pass filter network, the intermediate-frequency signal is sent again for input into the transconductance/amplification stage, then amplified in the transconductance/amplification stage and output. The mixer transconductance/amplification stage employs a current-reuse technique.
    Type: Application
    Filed: August 18, 2011
    Publication date: November 14, 2013
    Applicant: SOUTHEAST UNIVERSITY
    Inventors: Jianhui Wu, Chao Chen, Hong Li, Longxing Shi, Zixuan Wang, Jie Sun, Zhiyi Ye, Meng Zhang
  • Patent number: 8559213
    Abstract: A high-density and high-robustness sub-threshold memory cell circuit, having two PMOS transistors P1 and P2 and five NMOS transistors N1˜N5, wherein, the each base electrode of the two PMOS transistors and NMOS transistors N3, N4, and N5 is connected with the local grid electrode respectively; the base electrode of the NMOS transistors N1 and N2, are grounded respectively; the NMOS transistor N1 form an phase inverter with the PMOS transistor P1, and the NMOS transistor N2 form another phase inverter with the PMOS transistor P2; the two phase inverters are connected with each other in a cross coupling manner via the cut-off NMOS transistor N5, the output end of the phase inverter N1 and P1 directly connected to the input end of the phase inverter N2 and P2, and the output end of the phase inverter N2 and P2 connected to the input end of the phase inverter N1 and P1 via the cut-off NMOS transistor N5; the NMOS transistor N3 is connected with the write bit line (WBL) of the phase inverter N1 and P1, and the NMO
    Type: Grant
    Filed: August 13, 2009
    Date of Patent: October 15, 2013
    Assignee: Southeast University
    Inventors: Jun Yang, Na Bai, Jie Li, Chen Hu, Longxing Shi
  • Publication number: 20130153956
    Abstract: A silicon on insulator integrated high-current N type combined semiconductor device, which can improve the current density, comprises a P type substrate and a buried oxide layer arranged thereon. A P type epitaxial layer divided into a region I and a region II is arranged on the buried oxide layer. The region I comprises an N type drift region, a P type deep well, an N type buffer well, a P type drain region, an N type source region and a P type body contact region; a field oxide layer and agate oxide layer are arranged on a silicon surface, and a polysilicon lattice is arranged on the gate oxide layer. The region II comprises an N type triode drift region, a P type deep well, an N type triode buffer well, a P type emitting region, an N type base region, an N type source region and a P type body contact region; a field oxide layer and a gate oxide layer are arranged on a silicon surface, and a polysilicon lattice is arranged on the gate oxide layer.
    Type: Application
    Filed: July 11, 2011
    Publication date: June 20, 2013
    Applicant: SOUTHEAST UNIVERSITY
    Inventors: Longxing Shi, Qinsong Qian, Changlong Huo, Weifeng Sun, Shengli Lu
  • Publication number: 20130154583
    Abstract: The present invention discloses a dynamic voltage scaling system based on on-chip monitoring and voltage prediction, comprising a main circuit that has integrated on-chip monitoring circuits, a supply voltage scaling module, and voltage converters, wherein, the supply voltage scaling module comprises a sampling and statistics module designed to calculate the error rate of the main circuit in the current time slice, a state recording module designed to record the error rate and the corresponding supply voltage, an error prediction module, and a state transition probability generation module; the error prediction module predicts the error trend of the main circuit in a future time slice according to the state recording module and the state transition probability generation module, and generates regulation signals and sends to the corresponding voltage converters, so as to generate the voltage required for operation of the entire main circuit.
    Type: Application
    Filed: October 17, 2011
    Publication date: June 20, 2013
    Applicant: SOUTHEAST UNIVERSITY
    Inventors: Longxing Shi, Weiwei Shan, Jun Yang, Haolin Gu, Xinning Liu, Yang Zhang
  • Publication number: 20120326688
    Abstract: A switching power supply with a quick transient response is provided. A hysteretic control loop which comprises a hysteretic controller (117) and a control signal gate (116) is added to the original PWM control loop of the switching power supply. The hysteretic controller (117) is used to detect an output voltage (Vout) of the switching power supply and compare the output voltage (Vout) of the switching power supply with a reference voltage (Vref). When a load current (Iout) of the switching power supply is suddenly changed, the output voltage (Vout) of the switching power supply fluctuates. If the output voltage (Vout) of the switching power supply is in a setting range of the hysteretic voltage, output terminals (SELp, SELn) of the hysteretic controller (117) are in a low potential, and the control signal gate (116) selects output signals (Qp1, Qn1) from a PWM controller (101) as input signals of a gate signal drive circuit (106).
    Type: Application
    Filed: October 25, 2010
    Publication date: December 27, 2012
    Inventors: Weifeng Sun, Miao Yang, Youshan Jin, Sichao Liu, Shen Xu, Shengli Lu, Longxing Shi
  • Publication number: 20120256671
    Abstract: A switch level circuit (110) with dead time self-adapting control, which minimizes the switching loss in a switching power supply converter with synchronous rectification by changing a dead time between a high-side control transistor (10) and a low-side synchronous rectifying transistor (11). The switch level circuit (110) includes the high-side control transistor (10) and the low-side synchronous rectifying transistor (11) which are controlled to be on and off by external control signals, and a waveform with a given duty cycle is outputted at a node (LX) between the two transistors. The switch level circuit (110) also includes a control module for adjusting the dead time.
    Type: Application
    Filed: October 26, 2010
    Publication date: October 11, 2012
    Inventors: Shen Xu, Weifeng Sun, Miao Yang, Sichao Liu, Youshan Jin, Shengli Lu, Longxing Shi
  • Publication number: 20120069650
    Abstract: A high-density and high-robustness sub-threshold memory cell circuit, having two PMOS transistors P1 and P2 and five NMOS transistors N1˜N5, wherein, the each base electrode of the two PMOS transistors and NMOS transistors N3, N4, and N5 is connected with the local grid electrode respectively; the base electrode of the NMOS transistors N1 and N2, are grounded respectively; the NMOS transistor N1 form an phase inverter with the PMOS transistor P1, and the NMOS transistor N2 form another phase inverter with the PMOS transistor P2; the two phase inverters are connected with each other in a cross coupling manner via the cut-off NMOS transistor N5, the output end of the phase inverter N1 and P1 directly connected to the input end of the phase inverter N2 and P2, and the output end of the phase inverter N2 and P2 connected to the input end of the phase inverter N1 and P1 via the cut-off NMOS transistor N5; the NMOS transistor N3 is connected with the write bit line (WBL) of the phase inverter N1 and P1, and the NMO
    Type: Application
    Filed: August 13, 2009
    Publication date: March 22, 2012
    Applicant: SOUTHEAST UNIVERSITY
    Inventors: Jun Yang, Na Bai, Jie Li, Chen Hu, Longxing Shi
  • Patent number: 7557634
    Abstract: The low power consumption CMOS high voltage driving circuit relates to a kind of high voltage driving circuit for output driving, and there is an out buffer stage between the output end of the level switch stage and the input end of the high voltage output stage, comprising a high voltage PMOS pipe and a high voltage NMOS pipe. The source of the high voltage PMOS pipe is connected with the power supply, its gate electrode is connected with the output end of the upper level out buffer unit as the input end of the current level out buffer unit. The source of the high voltage NMOS pipe is put to earth, and its gate electrode serves as the receiving end of the 3ith sequence signal. The drain region of the high voltage PMOS pipe is connected with that of the high voltage NMOS pipe and is connected with the input end of the lower level out buffer unit as the output end of the current level out buffer unit.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: July 7, 2009
    Assignee: Southeast University
    Inventors: Longxing Shi, Weifeng Sun, Haisong Li, Shengli Lu, Yangbo Yi
  • Publication number: 20070205820
    Abstract: The low power consumption CMOS high voltage driving circuit relates to a kind of high voltage driving circuit for output driving, and there is an out buffer stage between the output end of the level switch stage and the input end of the high voltage output stage, comprising a high voltage PMOS pipe and a high voltage NMOS pipe. The source of the high voltage PMOS pipe is connected with the power supply, its gate electrode is connected with the output end of the upper level out buffer unit as the input end of the current level out buffer unit. The source of the high voltage NMOS pipe is put to earth, and its gate electrode serves as the receiving end of the 3ith sequence signal. The drain region of the high voltage PMOS pipe is connected with that of the high voltage NMOS pipe and is connected with the input end of the lower level out buffer unit as the output end of the current level out buffer unit.
    Type: Application
    Filed: October 20, 2004
    Publication date: September 6, 2007
    Inventors: Longxing Shi, Weifeng Sun, Haisong Li, Yangbo Yi