Patents by Inventor Peicheng Ju

Peicheng Ju 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: 6531857
    Abstract: A bandgap reference circuit that uses reduced substrate area while requiring relatively low voltage. The circuit may include a bipolar transistor with a resistor electrically connected across the emitter-base of the bipolar transistor. The resistor sums a first current with a second current and also generates a fractional VEB. The bandgap reference circuit may have a first current proportional to VEB, and a second current proportional to a PTAT current. An impedance booster may be incorporated into the circuit. Also disclosed is a method of regulating a voltage level using embodiments of the bandgap reference circuit.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: March 11, 2003
    Assignee: Agere Systems, Inc.
    Inventor: Peicheng Ju
  • Patent number: 6518906
    Abstract: The performance of a single-bit cell in a DAC is improved by decoupling the voltage swing across the load resistors from the output of the current steering device. This can be achieved by providing for a single-bit cell having a first load resistor R1 and a second load resistor R2, a current steering circuit, and a decoupling circuit operably coupled between the current steering circuit and the resistors R1, R2. The current steering circuit steers at least part of a current I1 through a circuit path towards either the first resistor R1 or the second resistor R2. The decoupling circuit decouples voltage swings across the load resistors R1, R2 from the current steering circuit.
    Type: Grant
    Filed: July 16, 2001
    Date of Patent: February 11, 2003
    Assignee: Agere Systems Guardian Corp.
    Inventors: Christopher J Abel, Joseph Anidjar, Peicheng Ju
  • Publication number: 20020093325
    Abstract: A bandgap reference circuit that may use reduced substrate area compared to prior art bandgap reference circuits, while requiring relatively low voltage. The circuit may include a bipolar transistor with a resistor electrically connected across the emitter-base of the bipolar transistor. The resistor sums a first current with a second current and also generates a fractional VEB. The bandgap reference circuit may have a first current proportional to VEB, and a second current proportional to a PTAT current. An impedance booster may be incorporated into the circuit. Also disclosed is a method of regulating a voltage level using embodiments of the bandgap reference circuit.
    Type: Application
    Filed: November 8, 2001
    Publication date: July 18, 2002
    Inventor: Peicheng Ju
  • Publication number: 20020030619
    Abstract: The performance of a single-bit cell in a DAC is improved by decoupling the voltage swing across the load resistors from the output of the current steering device. This can be achieved by providing for a single-bit cell having a first load resistor R1 and a second load resistor R2, a current steering circuit, and a decoupling circuit operably coupled between the current steering circuit and the resistors R1, R2. The current steering circuit steers at least part of a current I1 through a circuit path towards either the first resistor R1 or the second resistor R2. The decoupling circuit decouples voltage swings across the load resistors R1, R2 from the current steering circuit.
    Type: Application
    Filed: July 16, 2001
    Publication date: March 14, 2002
    Inventors: Christopher J. Abel, Joseph Anidjar, Peicheng Ju
  • Patent number: 6081218
    Abstract: A digital-to-analog converter (DAC) and a method of converting digital numbers to analog equivalents. In one embodiment, the DAC includes: (1) a data decoder that receives a digital number and an input clock signal and develops therefrom SIGN and M control signals and complementary .phi..sub.1 and .phi..sub.2 clock signals and (2) a conversion circuit, coupled to the data decoder and including first and second operational amplifiers (op amps), a switching circuit and sampling and integrating capacitors, the switching circuit coupling positive and negative reference voltages to the sampling capacitors as a function of states of the SIGN and M control signals and adjusting feedback loops associated with the first and second op amps as a function of states of the .phi..sub.1 and .phi..sub.2 clock signals, the first and second op amps generating a voltage difference at outputs thereof representing an analog equivalent of the digital number.
    Type: Grant
    Filed: January 30, 1998
    Date of Patent: June 27, 2000
    Assignee: Lucent Technologies, Inc.
    Inventors: Peicheng Ju, Krishnaswamy Nagaraj