Patents by Inventor Chang Siau

Chang Siau 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: 20230377626
    Abstract: One example of a memory device includes an array of flash memory cells, an array of Dynamic Random Access Memory (DRAM) memory cells, and a controller. The controller is configured to execute first instructions stored in the array of DRAM memory cells to access the array of flash memory cells.
    Type: Application
    Filed: May 18, 2022
    Publication date: November 23, 2023
    Applicant: MICRON TECHNOLOGY, INC.
    Inventors: Yankang He, Walter Di Francesco, Luca Nubile, Chang Siau
  • Patent number: 10908210
    Abstract: Systems and methods for die crack detection are disclosed. In one exemplary embodiment, a die includes a first conductive segment, an intermediate conductive segment, and a second conductive segment. The crack detection ring substantially surrounds the die according to a serpentine path having a plurality of legs, wherein each leg intersects the first conductive segment at a first intersection, an intermediate conductive segment at an intermediate intersection and a second conductive segment at a second intersection, wherein the intermediate intersection is horizontally offset from at least the first intersection and the second intersection.
    Type: Grant
    Filed: April 30, 2019
    Date of Patent: February 2, 2021
    Assignee: SanDisk Technologies LLC
    Inventors: Kirubakaran Periyannan, Naresh Battula, Chang Siau
  • Publication number: 20200103462
    Abstract: Systems and methods for die crack detection are disclosed. In one exemplary embodiment, a die includes a first conductive segment, an intermediate conductive segment, and a second conductive segment. The crack detection ring substantially surrounds the die according to a serpentine path having a plurality of legs, wherein each leg intersects the first conductive segment at a first intersection, an intermediate conductive segment at an intermediate intersection and a second conductive segment at a second intersection, wherein the intermediate intersection is horizontally offset from at least the first intersection and the second intersection.
    Type: Application
    Filed: April 30, 2019
    Publication date: April 2, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Kirubakaran PERIYANNAN, Naresh BATTULA, Chang SIAU
  • Publication number: 20190164581
    Abstract: Apparatuses, systems, and methods are disclosed for current sensing for non-volatile memory. A current to voltage conversion circuit may convert a current coupled to a sense amplifier to an analog voltage at a sense node. A voltage to digital conversion circuit may convert an analog voltage at a sense node to a digital signal, based on a voltage difference between the sense node and a comparison node during a strobe time. A bias circuit may bias a comparison node to a bias voltage other than a reference voltage, at least during a strobe time.
    Type: Application
    Filed: July 10, 2018
    Publication date: May 30, 2019
    Applicant: SanDisk Technologies LLC
    Inventors: HAO NGUYEN, GOPINATH BALAKRISHNAN, CHANG SIAU, SEUNGPIL LEE
  • Patent number: 9959078
    Abstract: Systems and methods for increasing performance and reducing power consumption of a non-volatile memory system while the system acquires status information from a plurality of memory die are described. The non-volatile memory system may include a plurality of memory die and a system controller for controlling operations performed by each memory die of the plurality of memory die (e.g., read operations, write operations, or erase operations). The system controller may transmit or broadcast a first status command to each memory die of the plurality of memory die and in response simultaneously or concurrently receive one or more sets of status information from each memory die of the plurality of memory die. The status information may include ready/busy status information (e.g., indicating that a memory die is able to receive new data), programming loop count information, and erase loop count information.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: May 1, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Grishma Shah, Jack Frayer, Aaron Olbrich, Chang Siau, Vidyabhushan Mohan, Gopinath Balakrishnan, Robert Ellis
  • Publication number: 20180061505
    Abstract: Technology is described herein for detecting a leakage current between a block select line and a conductive region that exists in multiple blocks of memory cells in a plane. The conductive region may be shared by at least one memory cell in multiple blocks. One example of the conductive region is a common source line that includes one or more local source lines and one or more global source lines. If the leakage current were to become high enough, the electrical short between the conductive region and the block select line could cause a plane level failure. If the leakage current is less than an amount that would cause a plane failure, but that indicates that the non-volatile memory device is susceptible to a plane failure, data may be moved out of the plane before the plane failure occurs. Thus, data loss may be prevented.
    Type: Application
    Filed: August 24, 2016
    Publication date: March 1, 2018
    Applicant: SanDisk Technologies LLC
    Inventors: Ashish Ghai, Lakshmi Kalpana Vakati, Ekamdeep Singh, Chang Siau, Gopinath Balakrishnan, Kapil Verma
  • Patent number: 9905307
    Abstract: Technology is described herein for detecting a leakage current between a block select line and a conductive region that exists in multiple blocks of memory cells in a plane. The conductive region may be shared by at least one memory cell in multiple blocks. One example of the conductive region is a common source line that includes one or more local source lines and one or more global source lines. If the leakage current were to become high enough, the electrical short between the conductive region and the block select line could cause a plane level failure. If the leakage current is less than an amount that would cause a plane failure, but that indicates that the non-volatile memory device is susceptible to a plane failure, data may be moved out of the plane before the plane failure occurs. Thus, data loss may be prevented.
    Type: Grant
    Filed: August 24, 2016
    Date of Patent: February 27, 2018
    Assignee: SanDisk Technologies LLC
    Inventors: Ashish Ghai, Lakshmi Kalpana Vakati, Ekamdeep Singh, Chang Siau, Gopinath Balakrishnan, Kapil Verma
  • Patent number: 9830987
    Abstract: Methods for precharging bit lines using closed-loop feedback are described. In one embodiment, a sense amplifier may include a bit line precharge circuit for setting a bit line to a read voltage prior to sensing a memory cell connected to the bit line. The bit line precharge circuit may include a first transistor in a source-follower configuration with a first gate and a first source node electrically coupled to the bit line. By applying local feedback from the first source node to the first gate, the bit line settling time may be reduced. In some cases, a first voltage applied to the first gate may be determined based on a first current drawn from the first bit line. Thus, the first voltage applied to the first gate may vary over time depending on the conductivity of a selected memory cell connected to the bit line.
    Type: Grant
    Filed: May 10, 2016
    Date of Patent: November 28, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Chang Siau, Xiaowei Jiang, Yingchang Chen
  • Patent number: 9715925
    Abstract: Methods for operating a non-volatile storage system are described. The non-volatile storage system includes a plurality of bit lines, a plurality of word line combs each comprising a plurality of word lines, and a plurality of resistance-switching memory elements. Each resistance-switching memory element is coupled between one of the bit lines and one of the word lines. The method includes calibrating a plurality of bias voltages for the word lines and bit lines based on estimates of data values stored in the resistance-switching memory elements.
    Type: Grant
    Filed: September 30, 2014
    Date of Patent: July 25, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Chang Siau, Tianhong Yan
  • Patent number: 9704572
    Abstract: A non-volatile memory is described that includes a sense amplifier that maintains a bit line voltage and output of the sense amplifier at a substantially constant voltage during read operations. During a preset phase, an output of the sense amplifier that is coupled to a selected bit line is grounded. At least one capacitor is precharged during the preset phase. During a sense phase, the sense amplifier output is disconnected from ground while the memory array is biased for reading a selected memory cell. A resulting cell current is integrated by the at least one capacitor. The integrated cell current discharges a sense node from the precharge level to an accurate voltage level based on the resulting cell current.
    Type: Grant
    Filed: March 20, 2015
    Date of Patent: July 11, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Yingchang Chen, Anurag Nigam, Chang Siau
  • Patent number: 9703719
    Abstract: Sensing techniques and associated circuitry are provided for use with a memory device. The techniques are suited for sensing operations involving even-numbered or odd-numbered bit lines. In one approach, the sensing circuitry includes left and right hand portions which have separate cache access lines, but are connected to a common output bus. A full data word can be output at a time by using a half word from the left hand portion and a half word from the right hand portion. Or, the sensing circuitry can be configured so that a full data word is output at a time from the left or right hand portion. One implementation provides an N-bit bus and N input paths for each of the left and right hand portions. Another implementation provides an N-bit bus and N/2 input paths for each of the left and right hand portions.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: July 11, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Gopinath Balakrishnan, Chang Siau, Yosuke Kato, Wanfang Tsai, Shingo Zaitsu
  • Patent number: 9646691
    Abstract: A monolithic three-dimensional memory array is provided that includes global bit lines disposed above a substrate, each global bit line having a long axis, vertically-oriented bit lines disposed above the global bit lines, word lines disposed above the global bit lines, memory cells coupled between the vertically-oriented bit lines and the word lines, and vertically-oriented bit line select transistors coupled between the vertically-oriented bit lines and the global bit lines. Each vertically-oriented bit line select transistor has a width, a first control terminal and a second control terminal. The word lines and the vertically-oriented bit lines have a half-pitch, and the width of the vertically-oriented bit line select transistors is between about two times the half-pitch and about three times the half-pitch. Vertical bit lines disposed above adjacent global bit lines are offset from one another in a direction along the long axis of the global bit lines.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: May 9, 2017
    Assignee: SanDisk Technologies LLC
    Inventor: Chang Siau
  • Patent number: 9595323
    Abstract: A method is provided for operating a non-volatile storage system that includes a plurality of bit lines, a word line comb including a plurality of word lines, and a plurality of memory elements, each memory element coupled between one of the bit lines and one of the word lines. The method includes receiving a current conducted by the word line comb, estimating a resistance of a conductive path between the word line comb and a selected word line voltage node, and generating a voltage at the selected word line voltage node based on the received current and the estimated resistance so that a voltage of the word line comb substantially equals a reference voltage.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: March 14, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Yingchang Chen, Jeffrey Koonyee Lee, Chang Siau, Anurag Nigam, Thomas Yan
  • Patent number: 9595325
    Abstract: A method is provided for reading a memory cell of a nonvolatile memory system. The method includes generating a hard bit and N soft bits for the memory cell in a total time corresponding to a single read latency period and N+1 data transfer times.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: March 14, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Chang Siau, Jeffrey Koon Yee Lee, Tianhong Yan, Yingchang Chen, Gopinath Balakrishnan, Tz-yi Liu
  • Patent number: 9576673
    Abstract: Disclosed herein are techniques for sensing multiple reference levels in non-volatile storage elements without changing the voltage on the selected word line. One aspect includes determining a first condition of a selected non-volatile storage element with respect to a first reference level based on whether a sensing transistor conducts in response to a sense voltage on a sense node. Then, a voltage on the source terminal of the sensing transistor is modified after determining the first condition with respect to the first reference level. A second condition of the selected non-volatile storage element is then determined with respect to a second reference level based on whether the sensing transistor conducts in response to the sense voltage on the sense node. This allows two different reference levels to be efficiently sensed. Dynamic power is saved due low capacitance of the sensing transistor relative to the sense node.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: February 21, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Xiaowei Jiang, Chang Siau, Siu Lung Chan
  • Patent number: 9543009
    Abstract: Methods for forming non-volatile storage elements in a non-volatile storage system are described. In some embodiments, during a forming operation, a cross-point memory array may be biased such that waste currents are minimized or eliminated. In one example, the memory array may be biased such that a first word line comb is set to a first voltage, a second word line comb interdigitated with the first word line comb is set to the first voltage, and selected vertical bit lines are set to a second voltage such that a forming voltage is applied across non-volatile storage elements to be formed. In some embodiments, a memory array may include a plurality of word line comb layers and a forming operation may be concurrently performed on non-volatile storage elements on all of the plurality of word line comb layers or a subset of the plurality of word line comb layers.
    Type: Grant
    Filed: October 20, 2015
    Date of Patent: January 10, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Chang Siau, Tianhong Yan
  • Patent number: 9536617
    Abstract: Systems and methods for reducing peak power supply current in a non-volatile memory system that includes a plurality of memory die are described. In some cases, prior to a first memory die of the plurality of memory die performing a particular memory operation (e.g., a programming operation), the first memory die may poll other memory die of the plurality of memory die to determine a total peak power supply current for the plurality of memory die. In response to detecting that the total peak power supply current for the plurality of memory die is at or above a peak current threshold (e.g., more than 200 mA), the first memory die may delay the performance of the particular memory operation or slow down the performance of the particular memory operation.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: January 3, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ali Al-Shamma, Farookh Moogat, Chang Siau, Grishma Shah, Kenneth Louie, Khanh Nguyen, Kapil Verma
  • Publication number: 20160328321
    Abstract: Sensing techniques and associated circuitry are provided for use with a memory device. The techniques are suited for sensing operations involving even-numbered or odd-numbered bit lines. In one approach, the sensing circuitry includes left and right hand portions which have separate cache access lines, but are connected to a common output bus. A full data word can be output at a time by using a half word from the left hand portion and a half word from the right hand portion. Or, the sensing circuitry can be configured so that a full data word is output at a time from the left or right hand portion. One implementation provides an N-bit bus and N input paths for each of the left and right hand portions. Another implementation provides an N-bit bus and N/2 input paths for each of the left and right hand portions.
    Type: Application
    Filed: October 30, 2015
    Publication date: November 10, 2016
    Applicant: SANDISK TECHNOLOGIES INC.
    Inventors: Gopinath Balakrishnan, Chang Siau, Yosuke Kato, Wanfang Tsai, Shingo Zaitsu
  • Patent number: 9472298
    Abstract: Determining dynamic read levels for memory cells is disclosed. A group of memory cells may be read at a pair of reference levels. Results of reading the group at the pair of reference levels are compared while the group is read at a different reference level. By comparing the results of reading the group at the pair of reference levels while reading the group at a different reference level, time is saved. Note that the reading and comparing can be repeated for other pairs of reference levels. The storage device may determine an adjusted read level based on the comparisons of the results for the different pairs of reference levels. The memory cells may be read at a set of reference levels. A voltage on a word line is not back down to ground between the reads in one aspect, which saves considerable time.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: October 18, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Kenneth Louie, Chang Siau, Gopinath Balakrishnan, Kapil Verma, Grishma Shah
  • Patent number: 9472280
    Abstract: Methods for forming non-volatile storage elements in a non-volatile storage system are described. In some embodiments, a plurality of forming operations may be performed in which non-volatile storage elements located near the far end of a plurality of word line fingers associated with a word line comb are formed prior to forming other non-volatile storage elements. In one example, non-volatile storage elements may be formed in each of the plurality of word line fingers in parallel and in an order that forms non-volatile storage elements in each of the plurality of word line fingers that are located near the far ends of the plurality of word line fingers before forming other non-volatile storage elements. Each non-volatile storage element that is formed during a forming operation may be current limited while a forming voltage is applied across the non-volatile storage element.
    Type: Grant
    Filed: June 7, 2015
    Date of Patent: October 18, 2016
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Chang Siau, Tianhong Yan