Patents by Inventor Won-Ho Choi
Won-Ho 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).
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Publication number: 20200311512Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter.Type: ApplicationFiled: June 15, 2020Publication date: October 1, 2020Applicant: SanDisk Technologies LLCInventors: Won Ho Choi, Pi-Feng Chiu, Wen Ma, Minghai Qin, Gerrit Jan Hemink, Martin Lueker-Boden
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Publication number: 20200311523Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter. The arrangement can be extended to ternary inputs to realize a ternary-binary network (TBN) by adding a circuit to detect 0 input values and adjust the accumulated count accordingly.Type: ApplicationFiled: March 28, 2019Publication date: October 1, 2020Applicant: SanDisk Technologies LLCInventors: Tung Thanh Hoang, Won Ho Choi, Martin Lueker-Boden
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Patent number: 10790016Abstract: Neuron circuit structures are presented which employ magnetic tunnel junction (MTJ) elements that change state probabilistically in response to application of electrical source currents that emulate synaptic activity. Some implementations form probabilistic neuron circuits using homogeneous perpendicular spin-transfer torque (STT) MTJ elements. These neuron circuits include a perpendicular STT reference MTJ element coupled via an electrical node with a perpendicular STT neuron MTJ element that can change state. The electrical node for each neuron circuit couples a neuron MTJ element or “perturbation” element to a reference element, and also to an electrical current employed to influence probabilistic magnetization state changes in the perturbation MTJ element. A read current can be applied to the perturbation element to produce an output voltage at the electrical node indicative of a magnetization state of the perturbation element.Type: GrantFiled: March 2, 2018Date of Patent: September 29, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Won Ho Choi, Young-Suk Choi
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Publication number: 20200257936Abstract: Exemplary methods and apparatus are disclosed that implement super-sparse image/video compression by storing image dictionary elements within a cross-bar resistive random access memory (ReRAM) array (or other suitable cross-bar NVM array). In illustrative examples, each column of the cross-bar ReRAM array stores the values for one dictionary element (such as one 4×4 dictionary element). Methods and apparatus are described for training (configuring) the cross-bar ReRAM array to generate and store the dictionary elements by sequentially applying patches from training images to the array using an unstructured Hebbian training procedure. Additionally, methods and apparatus are described for compressing an input image by applying patches from the input image to the ReRAM array to read out cross-bar column indices identifying the columns storing the various dictionary elements that best fit the image. This may be done in parallel using a set of ReRAM arrays.Type: ApplicationFiled: February 13, 2019Publication date: August 13, 2020Inventors: Wen Ma, Minghai Qin, Won Ho Choi, Pi-Feng Chiu, Martin Lueker-Boden
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Publication number: 20200258702Abstract: A gas circuit breaker of a gas-insulated switchgear is proposed. The gas circuit breaker includes a driving part (10) that operates when fault current occurs, and a fixed part (20) that is coupled to and separated from the driving part (10), thereby establishing electric connection. The driving part (10) includes a first main electrode (12) and a first arc electrode (14). The fixed part (20) includes a second main electrode (22) that is coupled to and separated from the first main electrode (12). The fixed part (20) also includes a second arc electrode (24). The first arc electrode (14) and the second arc electrode (24) are separated after separation of the first and second main electrodes (12, 22), thereby generating an arc. A first activation lever (30) is connected to a first connection link (19). A second activation lever (40) is connected to the first activation lever (30).Type: ApplicationFiled: May 28, 2018Publication date: August 13, 2020Inventors: Seung Kyu LEE, Kwang Jin KIM, So Hae CHOI, Chang Hwan YANG, Won Ho CHOI
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Patent number: 10732933Abstract: True random number generation (TRNG) circuits are presented which employ magnetic tunnel junction (MTJ) elements that can change magnetization state probabilistically in response to application of electrical pulses. Some implementations include pulse generators which apply perturbation sequences to the MTJ elements. The MTJ elements responsively produce randomized outputs related to changes in magnetization states. Probability compensators are included which monitor for deviations in measured probabilities in the randomized outputs from a target probability. The probability compensators make adjustments to the perturbation sequences to influence probabilistic changes in the magnetization states of the MTJ elements and bring the measured probabilities to within a predetermined deviation from the target probability.Type: GrantFiled: May 10, 2018Date of Patent: August 4, 2020Assignee: SANDISK TECHNOLOGIES LLCInventor: Won Ho Choi
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Publication number: 20200192970Abstract: An innovative low-bit-width device may include a first digital-to-analog converter (DAC), a second DAC, a plurality of non-volatile memory (NVM) weight arrays, one or more analog-to-digital converters (ADCs), and a neural circuit. The first DAC is configured to convert a digital input signal into an analog input signal. The second DAC is configured to convert a digital previous hidden state (PHS) signal into an analog PHS signal. NVM weight arrays are configured to compute vector matrix multiplication (VMM) arrays based on the analog input signal and the analog PHS signal. The NVM weight arrays are coupled to the first DAC and the second DAC. The one or more ADCs are coupled to the plurality of NVM weight arrays and are configured to convert the VMM arrays into digital VMM values. The neural circuit is configured to process the digital VMM values into a new hidden state.Type: ApplicationFiled: June 25, 2019Publication date: June 18, 2020Inventors: Wen Ma, Pi-Feng Chiu, Minghai Qin, Won Ho Choi, Martin Lueker-Boden
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Patent number: 10643119Abstract: Use of a non-volatile memory array architecture to realize a neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a neural network is formed by a differential memory cell of two individual memory cells, such as a memory cells having a programmable resistance, each connected between a corresponding one of a word line pair and a shared bit line. An input is applied as a pattern of voltage values on word line pairs connected to the unit synapses to perform the multiplication of the input with the weight by determining a voltage level on the shared bit line. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a summation circuit.Type: GrantFiled: May 7, 2019Date of Patent: May 5, 2020Assignee: SanDisk Technologies LLCInventors: Pi-Feng Chiu, Won Ho Choi, Wen Ma, Martin Lueker-Boden
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Patent number: 10643705Abstract: Use of a non-volatile memory array architecture to realize a neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a neural network is formed by a differential memory cell of two individual memory cells, such as a memory cells having a programmable resistance, each connected between a corresponding one of a word line pair and a shared bit line. An input is applied as a pattern of voltage values on word line pairs connected to the unit synapses to perform the multiplication of the input with the weight by determining a voltage level on the shared bit line. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a summation circuit. The approach can be extended from binary weights to multi-bit weight values by use of multiple differential memory cells for a weight.Type: GrantFiled: May 16, 2019Date of Patent: May 5, 2020Assignee: SanDisk Technologies LLCInventors: Won Ho Choi, Pi-Feng Chiu, Wen Ma, Martin Lueker-Boden
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Publication number: 20200117982Abstract: Enhanced techniques and circuitry are presented herein for artificial neural networks. These artificial neural networks are formed from artificial synapses, which in the implementations herein comprise a memory arrays having non-volatile memory elements. In one implementation, an apparatus comprises a plurality of non-volatile memory arrays configured to store weight values for an artificial neural network. Each of the plurality of non-volatile memory arrays can be configured to receive data from a unified buffer shared among the plurality of non-volatile memory arrays, operate on the data, and shift at least portions of the data to another of the plurality of non-volatile memory arrays.Type: ApplicationFiled: March 15, 2019Publication date: April 16, 2020Inventors: Pi-Feng Chiu, Won Ho Choi, Wen Ma, Martin Lueker-Boden
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Publication number: 20200075099Abstract: Ternary content addressable memory (TCAM) circuits are provided herein. In one example implementation, a TCAM circuit can include a first spin-orbit torque (SOT) magnetic tunnel junction (MTJ) element having a pinned layer coupled to a first read transistor controlled by a first search line, and having a spin hall effect (SHE) layer coupled in a first configuration across complemented write inputs. The TCAM circuit can include a second SOT MTJ element having a pinned layer coupled to a second read transistor controlled by a second search line, and having a SHE layer coupled in a second configuration across the complemented write inputs. The TCAM circuit can include a bias transistor configured to provide a bias voltage to drain terminals of the first read transistor and the second read transistor, and a voltage keeper element that couples the drain terminals to a match indicator line.Type: ApplicationFiled: January 22, 2019Publication date: March 5, 2020Inventors: Won Ho Choi, Jongyeon Kim
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Patent number: 10566048Abstract: Apparatus, systems, methods, and computer program products for managing refresh operations in memory devices are disclosed. An apparatus includes a memory device including a plurality of memory cells comprising an associated set of counters and a controller for the memory device. A controller is configured to randomly increment a counter associated with a memory cell in response to write disturbances for the memory cell. A controller is configured, in response to a counter being randomly incremented to a predetermined count, perform a refresh operation on a memory cell.Type: GrantFiled: November 13, 2017Date of Patent: February 18, 2020Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Minghai Qin, Won Ho Choi, Zvonimir Bandic
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Publication number: 20200034697Abstract: Use of a NAND array architecture to realize a binary neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a BNN is stored in a pair of series connected memory cells. A binary input is applied as a pattern of voltage values on a pair of word lines connected to the unit synapse to perform the multiplication of the input with the weight by determining whether or not the unit synapse conducts. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a counter.Type: ApplicationFiled: March 28, 2019Publication date: January 30, 2020Applicant: SanDisk Technologies LLCInventors: Won Ho Choi, Pi-Feng Chiu, Wen Ma, Minghai Qin, Gerrit Jan Hemink, Martin Lueker-Boden
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Publication number: 20200035305Abstract: Use of a non-volatile memory array architecture to realize a neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a neural network is formed by a differential memory cell of two individual memory cells, such as a memory cells having a programmable resistance, each connected between a corresponding one of a word line pair and a shared bit line. An input is applied as a pattern of voltage values on word line pairs connected to the unit synapses to perform the multiplication of the input with the weight by determining a voltage level on the shared bit line. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a summation circuit. The approach can be extended from binary weights to multi-bit weight values by use of multiple differential memory cells for a weight.Type: ApplicationFiled: May 16, 2019Publication date: January 30, 2020Applicant: SanDisk Technologies LLCInventors: Won Ho Choi, Pi-Feng Chiu, Wen Ma, Martin Lueker-Boden
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Publication number: 20200034686Abstract: Use of a non-volatile memory array architecture to realize a neural network (BNN) allows for matrix multiplication and accumulation to be performed within the memory array. A unit synapse for storing a weight of a neural network is formed by a differential memory cell of two individual memory cells, such as a memory cells having a programmable resistance, each connected between a corresponding one of a word line pair and a shared bit line. An input is applied as a pattern of voltage values on word line pairs connected to the unit synapses to perform the multiplication of the input with the weight by determining a voltage level on the shared bit line. The results of such multiplications are determined by a sense amplifier, with the results accumulated by a summation circuit.Type: ApplicationFiled: May 7, 2019Publication date: January 30, 2020Applicant: SanDisk Technologies LLCInventors: Pi-Feng Chiu, Won Ho Choi, Wen Ma, Martin Lueker-Boden
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Publication number: 20200012924Abstract: Enhanced techniques and circuitry are presented herein for artificial neural networks. These artificial neural networks are formed from artificial neurons, which in the implementations herein comprise a memory array having non-volatile memory elements. Neural connections among the artificial neurons are formed by interconnect circuitry coupled to input control lines and output control lines of the memory array to subdivide the memory array into a plurality of layers of the artificial neural network. Control circuitry is configured to transmit a plurality of iterations of an input value on input control lines of a first layer of the artificial neural network for inference operations by at least one or more additional layers. The control circuitry is also configured to apply an averaging function across output values successively presented on output control lines of a last layer of the artificial neural network from each iteration of the input value.Type: ApplicationFiled: November 5, 2018Publication date: January 9, 2020Inventors: Wen Ma, Minghai Qin, Won Ho Choi, Pi-Feng Chiu, Martin Van Lueker-Boden
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Patent number: 10528643Abstract: Technology is described herein for performing multiplication using non-volatile memory cells. A multiplicand may be stored a node that includes multiple non-volatile memory cells. Each memory cell in a node may be programmed to one of two physical states, with each non-volatile memory cell storing a different bit of the multiplicand. Multiplication may be performed by applying a multiply voltage to the node of memory cells and processing memory cell currents from the memory cells in the node. The memory cell current from each memory cell in the node is multiplied by a different power of two. The multiplied signals are summed to generate a “result signal,’ which represents a product of the multiplier and a multiplicand stored in the node. If desired, “binary memory cells” may be used to perform multiplication. Vector/vector and vector/matrix multiplication may also be performed.Type: GrantFiled: August 1, 2018Date of Patent: January 7, 2020Assignee: SanDisk Technologies LLCInventors: Won Ho Choi, Martin Lueker-Boden
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Patent number: 10497438Abstract: Apparatuses, systems, methods, and computer program products are disclosed for memory array addressing. An addressing circuit is configured to receive an address for an operation on an array of multiple memory regions. An address includes a row address and a column address both multiplexed into the address and received with an activate command for an operation. A row buffer for an array of multiple memory regions is configured to store data identified by multiplexed row and column addresses from the multiple memory regions. Data of an operation is selected from a row buffer based on a second address received with a subsequent command for the operation.Type: GrantFiled: June 28, 2017Date of Patent: December 3, 2019Assignee: SanDisk Technologies LLCInventors: Won Ho Choi, Ward Parkinson, Zvonimir Bandic, James O'Toole, Martin Lueker-Boden
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Publication number: 20190347074Abstract: True random number generation (TRNG) circuits are presented which employ magnetic tunnel junction (MTJ) elements that can change magnetization state probabilistically in response to application of electrical pulses. Some implementations include pulse generators which apply perturbation sequences to the MTJ elements. The MTJ elements responsively produce randomized outputs related to changes in magnetization states. Probability compensators are included which monitor for deviations in measured probabilities in the randomized outputs from a target probability. The probability compensators make adjustments to the perturbation sequences to influence probabilistic changes in the magnetization states of the MTJ elements and bring the measured probabilities to within a predetermined deviation from the target probability.Type: ApplicationFiled: May 10, 2018Publication date: November 14, 2019Inventor: Won Ho Choi
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Publication number: 20190312196Abstract: Apparatuses, systems, and methods are disclosed for magnetoresistive random access memory. A magnetic tunnel junction (MTJ) for storing data may include a reference layer. A free layer of an MTJ may be separated from a reference layer by a barrier layer. A free layer may be configured such that one or more resistance states for an MTJ correspond to one or more positions of a magnetic domain wall within the free layer. A domain stabilization layer may be coupled to a portion of a free layer, and may be configured to prevent migration of a domain wall into the portion of the free layer.Type: ApplicationFiled: June 24, 2019Publication date: October 10, 2019Applicant: SanDisk Technologies LLCInventors: Young-Suk Choi, Won Ho Choi