Patents by Inventor Myung Chan Choi

Myung Chan Choi 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: 11004499
    Abstract: A latency control circuit and method are provided. The latency control circuit includes a DLL circuit, a latency counter circuit, a synchronization circuit, and a delay line circuit. The DLL circuit enters an inactive state after locking the delay time and provides an active signal at a disable state, delay locking information and loop delay information during the inactive state. The synchronization circuit stops providing a first clock signal according to the active signal at the disable state and then synchronously outputs an operation enabling signal and a second clock signal in response to an enablement of the operation signal. The delay line circuit receives the delay locking information, the operation enabling signal, and the second clock signal and outputs an operation delay signal and an output clock signal after the delay time.
    Type: Grant
    Filed: May 8, 2020
    Date of Patent: May 11, 2021
    Assignee: Winbond Electronics Corp.
    Inventors: Young-Tae Kim, Chan-Seok Park, Youngjoo Choi, Myung-Chan Choi
  • Patent number: 10564692
    Abstract: The disclosure is directed to a memory device and a power reduction method of the same memory device. In an aspect, the disclosure is directed to a memory device which includes not limited to a plurality of memory banks, each having a power switch, a plurality of functional blocks for reading and writing to the plurality of memory banks and include a plurality of power switches as each functional block of the plurality of function blocks has a different power switch which turns on or turns off the functional block, a mode register circuit having a plurality of mode registers which determines whether one or more of the plurality of memory banks would maintain data storage or not, and a control logic circuit for either powering on or powering off each of the plurality of memory banks and each of the plurality of the functional blocks.
    Type: Grant
    Filed: March 27, 2018
    Date of Patent: February 18, 2020
    Assignee: Windbond Electronics Corp.
    Inventor: Myung-Chan Choi
  • Publication number: 20190304530
    Abstract: The disclosure is directed to a memory device and a power reduction method of the same memory device. In an aspect, the disclosure is directed to a memory device which includes not limited to a plurality of memory banks, each having a power switch, a plurality of functional blocks for reading and writing to the plurality of memory banks and include a plurality of power switches as each functional block of the plurality of function blocks has a different power switch which turns on or turns off the functional block, a mode register circuit having a plurality of mode registers which determines whether one or more of the plurality of memory banks would maintain data storage or not, and a control logic circuit for either powering on or powering off each of the plurality of memory banks and each of the plurality of the functional blocks.
    Type: Application
    Filed: March 27, 2018
    Publication date: October 3, 2019
    Applicant: Winbond Electronics Corp.
    Inventor: Myung-Chan Choi
  • Patent number: 10217497
    Abstract: A memory device includes a delay locked loop (DLL) circuit to receive an external clock, and delay the external clock by a DLL delay time to provide a DLL clock, an output driver to output the DLL clock as a data strobe signal, and a DLL offset control circuit configured to receive at least one of a plurality of functional statement commands, and adjust the DLL delay time based on the at least one of the functional statement commands. Each one of the DLL circuit and the output driver is selectively powered according to the at least one of the functional statement commands.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: February 26, 2019
    Assignee: Winbond Electronics Corporation
    Inventor: Myung Chan Choi
  • Publication number: 20180358061
    Abstract: A memory device includes a delay locked loop (DLL) circuit to receive an external clock, and delay the external clock by a DLL delay time to provide a DLL clock, an output driver to output the DLL clock as a data strobe signal, and a DLL offset control circuit configured to receive at least one of a plurality of functional statement commands, and adjust the DLL delay tine based on the at least one of the functional statement commands. Each one of the DLL circuit and the output driver is selectively powered according to the at least one of the functional statement commands.
    Type: Application
    Filed: June 7, 2017
    Publication date: December 13, 2018
    Inventor: Myung Chan CHOI
  • Patent number: 9721675
    Abstract: An input circuit of a memory device includes an input receiver to receive an input signal, a clock receiver to receive a clock signal, a data latch, an input signal delay path coupled to the input receiver and configured to provide a delayed internal input signal to the data latch, a first clock signal delay path coupled to the clock receiver and configured to provide a first delayed internal clock signal, a second clock signal delay path coupled to the input receiver and configured to provide a second delayed internal clock signal, and a multiplexer coupled to receive and select one of the first delayed internal clock signal and the second delayed internal clock signal in response to a test mode control signal, and to provide the selected signal to the data latch.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: August 1, 2017
    Assignee: Winbond Electronics Corporation
    Inventor: Myung Chan Choi
  • Patent number: 9202532
    Abstract: A decoder circuit, responsive to a burst sequence control signal, for accessing a memory location in a memory array. The decoder circuit receives an address signal and outputs a plurality of first select lines. Logic circuitry receives these first select lines and a burst sequence control signal and outputs a plurality of second select lines. When the bust sequence control signal is unasserted, the logic circuitry passes through to the plurality of second select lines the signals received on the plurality of first select lines. When the burst sequence control signal is asserted, the logic circuitry performs a logical operation on the signals received on the plurality of first select lines and outputs the result on the plurality of second select lines.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: December 1, 2015
    Assignee: WINBOND ELECTRONICS CORP.
    Inventor: Myung Chan Choi
  • Publication number: 20140071770
    Abstract: A decoder circuit, responsive to a burst sequence control signal, for accessing a memory location in a memory array. The decoder circuit receives an address signal and outputs a plurality of first select lines. Logic circuitry receives these first select lines and a burst sequence control signal and outputs a plurality of second select lines. When the bust sequence control signal is unasserted, the logic circuitry passes through to the plurality of second select lines the signals received on the plurality of first select lines. When the burst sequence control signal is asserted, the logic circuitry performs a logical operation on the signals received on the plurality of first select lines and outputs the result on the plurality of second select lines.
    Type: Application
    Filed: September 13, 2012
    Publication date: March 13, 2014
    Inventor: Myung Chan Choi
  • Publication number: 20120201085
    Abstract: Circuits and methods for suppressing integrated circuit leakage currents are described. Many of these circuits and methods are particularly well-suited for use in dynamic memory circuits. Examples describe the use of power, ground, or both and power and ground source transistors used for generating virtual voltages. An aspect of the invention describes lowering refresh current. An aspect describes reducing the standby current. An aspect of the invention describes lowering leakage resulting from duplicated circuits, such as row decoders and word line drivers. An aspect describes methods of performing early wake-up of source transistors. A number of source transistor control mechanisms are taught. Circuit layouts methods are taught for optimizing integrated circuit layouts using the source transistors.
    Type: Application
    Filed: April 19, 2011
    Publication date: August 9, 2012
    Applicant: ZMOS TECHNOLOGY, INC.
    Inventors: Seung-Moon Yoo, Myung Chan Choi, Young Tae Kim, Jung Ju Son, Sang-Kyun Han, Sun Hyoung Lee
  • Patent number: 7961541
    Abstract: An apparatus and method for reducing power consumption within dynamic memory devices having internal self-refresh circuitry. The circuits for generating isolator control (ISO), pre-decoded row address (PXID) and/or word enable (WE) signals are configured in response to receipt of self-refresh and refresh counter signals to output different timing and sequencing when in self-refresh mode than when in normal mode of the memory device. Conventionally, ISO signals are controlled from a block selection circuit which also controls bit line equalization (BLEQ) and sense amplifier enable (SAPN). While in conventional circuits the PXID and WE signals are generated in response to the output of the address decoder and thus have a fixed timing in relation to the output of the address decoder. The use of different timing and sequencing can lower power consumption, such as by outputting fewer signal transitions per block during self-refresh.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: June 14, 2011
    Assignee: ZMOS Technology, Inc.
    Inventors: Myung Chan-Choi, Seung-Moon Yoo, Arthur Kwon
  • Patent number: 7929367
    Abstract: Circuits and methods for suppressing integrated circuit leakage currents are described. Many of these circuits and methods are particularly well-suited for use in dynamic memory circuits. Examples describe the use of power, ground, or both and power and ground source transistors used for generating virtual voltages. An aspect of the invention describes lowering refresh current. An aspect describes reducing the standby current. An aspect of the invention describes lowering leakage resulting from duplicated circuits, such as row decoders and word line drivers. An aspect describes methods of performing early wake-up of source transistors. A number of source transistor control mechanisms are taught. Circuit layouts methods are taught for optimizing integrated circuit layouts using the source transistors.
    Type: Grant
    Filed: September 22, 2006
    Date of Patent: April 19, 2011
    Assignee: Zmos Technology, Inc.
    Inventors: Seung-Moon Yoo, Myung Chan Choi, Young Tae Kim, Sung Ju Son, Sang-Kyun Han, Sun Hyoung Lee
  • Patent number: 7839701
    Abstract: Circuits and methods are described for reducing leakage current and speeding access within dynamic random access memory circuit devices. A number of beneficial aspects are described. A circuit is described for an enhanced sense amplifier utilizing complementary drain transistors coupled to the sense or restore signals and driven by gate voltages which extend outside of the voltage range between VSS and VDD. The drain transistors are self reverse-biased in a standby mode. A method is also described for reducing leaking in non-complementary sense amplifiers by modifying the sense and restore gate voltages. Another aspect is a new negative word line method utilizing stacked pull-down transistors and a multi-step control circuit. In addition a level shifter scheme is described for preventing unwanted current flow between voltage sources while discharging control signal PX.
    Type: Grant
    Filed: June 27, 2007
    Date of Patent: November 23, 2010
    Assignee: ZMOS Technology, Inc.
    Inventor: Myung Chan Choi
  • Patent number: 7705625
    Abstract: Source transistor configurations are described for reducing leakage and delay within integrated circuits. Virtual power and ground nodes are supported with the use of stacked transistor configurations, such as a two transistor stack between a first virtual supply connection and VSS, and a second virtual supply connection and VDD. Gate drives of these stacked transistors are modulated with different voltage levels in response to the operating power mode of the circuit, for example active mode, active-standby mode, and deep power-down mode. Means for driving these source stacks are described. In one embodiment separate virtual nodes are adapted for different types of circuits, such as buffers, row address strobe, and column address strobe. Other techniques, such as directional placement of the transistors is also described.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: April 27, 2010
    Assignee: Zmos Technology, Inc.
    Inventors: Seung-Moon Yoo, Jae Hoon Yoo, Jeongduk Sohn, Sung Ju Son, Myung Chan Choi, Young Tae Kim, Oh Sang Yoon, Sang-Kyun Han
  • Publication number: 20090154278
    Abstract: An apparatus and method for reducing power consumption within dynamic memory devices having internal self-refresh circuitry. The circuits for generating isolator control (ISO), pre-decoded row address (PXID) and/or word enable (WE) signals are configured in response to receipt of self-refresh and refresh counter signals to output different timing and sequencing when in self-refresh mode than when in normal mode of the memory device. Conventionally, ISO signals are controlled from a block selection circuit which also controls bit line equalization (BLEQ) and sense amplifier enable (SAPN). While in conventional circuits the PXID and WE signals are generated in response to the output of the address decoder and thus have a fixed timing in relation to the output of the address decoder. The use of different timing and sequencing can lower power consumption, such as by outputting fewer signal transitions per block during self-refresh.
    Type: Application
    Filed: December 11, 2008
    Publication date: June 18, 2009
    Applicant: ZMOS TECHNOLOGY, INC.
    Inventors: Myung Chan-Choi, Seung-Moon Yoo, Arthur Kwon
  • Patent number: 7522464
    Abstract: Dynamic Random Access Memory (DRAM) circuits and methods are described for reducing leakage and increasing repaired yield. These objects are accomplished according to the invention by grouping refresh cycles within a single activation of power control, the use of limiting circuits or fuses to mitigate power losses associated with micro-bridging of bit-lines and word-lines, modulating the bit-line voltage at the end of precharge cycles, configuring refresh control circuits to use redundant word-lines in generating additional refresh cycles for redundant rows of memory cells, and combinations thereof. In one aspect, word-line fuses indicate modes of use as: unused, replacement, additional refresh, and replacement with additional refresh. The refresh control circuit utilizes these modes in combination with the X-address stored in the word-line fuses for controlling the generation of additional refresh cycles toward overcoming insufficient data retention intervals in select memory cell rows.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: April 21, 2009
    Assignee: ZMOS Technology, Inc.
    Inventors: Seung-Moon Yoo, Myung Chan Choi, Sangho Shin, Sang-Kyun Han
  • Patent number: 7324390
    Abstract: Circuits and methods are described for reducing leakage current and speeding access within dynamic random access memory circuit devices. A number of beneficial aspects are described. A circuit is described for an enhanced sense amplifier utilizing complementary drain transistors coupled to the sense or restore signals and driven by gate voltages which extend outside of the voltage range between VSS and VDD. The drain transistors are self reverse-biased in a standby mode. A method is also described for reducing leaking in non-complementary sense amplifiers by modifying the sense and restore gate voltages. Another aspect is a new negative word line method utilizing stacked pull-down transistors and a multi-step control circuit. In addition a level shifter scheme is described for preventing unwanted current flow between voltage sources while discharging control signal PX.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: January 29, 2008
    Assignee: Zmos Technology, Inc.
    Inventor: Myung Chan Choi
  • Patent number: 7301322
    Abstract: A CMOS constant voltage generator circuit having input and output stages and at least one compensation stage. Each stage can comprise a single transistor or more typically a transistor stack. Current mirroring is performed between the input stage and compensation stage, as well as preferably between the input stage and output stage. The compensation stage also provides additional biasing to a transistor in the output stage to increase voltage regulation. Optionally, degeneration resistors (passive or active) are coupled to the source side, drain side, or a combination of source and drain sides in the compensation and output stages. Optionally, additional diode-coupled transistors are incorporated in the transistor stack of the output stage. The circuit provides accurate voltage reference (Vref) output with lowered sensitivity to temperature and supply voltage.
    Type: Grant
    Filed: January 10, 2005
    Date of Patent: November 27, 2007
    Assignee: ZMOS Technology, Inc.
    Inventor: Myung Chan Choi
  • Publication number: 20070081405
    Abstract: Circuits and methods for suppressing integrated circuit leakage currents are described. Many of these circuits and methods are particularly well-suited for use in dynamic memory circuits. Examples describe the use of power, ground, or both and power and ground source transistors used for generating virtual voltages. An aspect of the invention describes lowering refresh current. An aspect describes reducing the standby current. An aspect of the invention describes lowering leakage resulting from duplicated circuits, such as row decoders and word line drivers. An aspect describes methods of performing early wake-up of source transistors. A number of source transistor control mechanisms are taught. Circuit layouts methods are taught for optimizing integrated circuit layouts using the source transistors.
    Type: Application
    Filed: September 22, 2006
    Publication date: April 12, 2007
    Applicant: ZMOS TECHNOLOGY, INC.
    Inventors: Seung-Moon Yoo, Myung Chan Choi, Young Tae Kim, Sung Ju Son, Sang-Kyun Han, Sun Hyoung Lee
  • Patent number: 7082048
    Abstract: Circuits and methods are described for reducing leakage current and speeding access within dynamic random access memory circuit devices. A number of beneficial aspects are described. A circuit is described for an enhanced sense amplifier utilizing complementary drain transistors coupled to the sense or restore signals and driven by gate voltages which extend outside of the voltage range between VSS and VDD. The drain transistors are self reverse-biased in a standby mode. A method is also described for reducing leaking in non-complementary sense amplifiers by modifying the sense and restore gate voltages. Another aspect is a new negative word line method utilizing stacked pull-down transistors and a multi-step control circuit. In addition a level shifter scheme is described for preventing unwanted current flow between voltage sources while discharging control signal PX.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: July 25, 2006
    Assignee: ZMOS Technology, Inc.
    Inventor: Myung Chan Choi
  • Patent number: 5923612
    Abstract: A semiconductor memory device having a macro command function includes a macro storage section for storing a series of external instructions synchronized with a clock signal and a plurality of interval data corresponding to a number of clock pulses occurring between the external instructions. A counter is also included for counting the clock pulses and for producing an output representing a number of clock pulses occurring since an initialization of the counter, and a selecting section is included for selecting between a current external instruction synchronized with the clock signal and the external instructions read out from the macro storage section.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: July 13, 1999
    Assignee: Samsung Electronic. Co., Ltd.
    Inventors: Chul Woo Park, Myung-Chan Choi