Patents by Inventor Qui Vi Nguyen
Qui Vi Nguyen 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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Patent number: 10614894Abstract: Disclosed includes a memory device and a method of operating the memory device. A voltage is applied to a word line coupled to first memory transistors of a first plurality of strings of transistors and second memory transistors of a second plurality of strings of transistors. A current flow through one or more of the first plurality of strings of transistors is enabled, while applying the voltage to the word line. A current flow through the second plurality of strings of transistors is disabled by floating source terminals and drain terminals of the second memory transistors, while enabling the current flow through the one or more of the first plurality of strings of transistors.Type: GrantFiled: January 12, 2018Date of Patent: April 7, 2020Assignee: SanDisk Technologies LLCInventors: Qui Vi Nguyen, Jong Hak Yuh, Khanh Nguyen
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Patent number: 10475493Abstract: This disclosure provides techniques for reducing leakage current in a non-volatile memory that does not include a local interconnect. In one example, a low-voltage pulse can be applied to all of the word-lines in all of the blocks of the non-volatile memory. The low-voltage pulse can be applied during a period in which the row decoder is typically idle in order to reduce the total amount of time required to program the non-volatile memory. After the conclusion low-voltage pulse, a global control line voltage can be applied at about the same level as the low-voltage pulse to keep the word-lines floating when the pulse is no longer applied.Type: GrantFiled: December 15, 2017Date of Patent: November 12, 2019Assignee: SanDisk Technologies LLCInventors: Manabu Sakai, Qui Vi Nguyen, Yen-Lung Li
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Publication number: 20190221269Abstract: Disclosed includes a memory device and a method of operating the memory device. A voltage is applied to a word line coupled to first memory transistors of a first plurality of strings of transistors and second memory transistors of a second plurality of strings of transistors. A current flow through one or more of the first plurality of strings of transistors is enabled, while applying the voltage to the word line. A current flow through the second plurality of strings of transistors is disabled by floating source terminals and drain terminals of the second memory transistors, while enabling the current flow through the one or more of the first plurality of strings of transistors.Type: ApplicationFiled: January 12, 2018Publication date: July 18, 2019Inventors: QUI VI NGUYEN, JONG HAK YUH, KHANH NGUYEN
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Publication number: 20190066789Abstract: This disclosure provides techniques for reducing leakage current in a non-volatile memory that does not include a local interconnect. In one example, a low-voltage pulse can be applied to all of the word-lines in all of the blocks of the non-volatile memory. The low-voltage pulse can be applied during a period in which the row decoder is typically idle in order to reduce the total amount of time required to program the non-volatile memory. After the conclusion low-voltage pulse, a global control line voltage can be applied at about the same level as the low-voltage pulse to keep the word-lines floating when the pulse is no longer applied.Type: ApplicationFiled: December 15, 2017Publication date: February 28, 2019Applicant: SanDisk Technologies LLCInventors: Manabu Sakai, Qui Vi Nguyen, Yen-Lung Li
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Patent number: 9653126Abstract: Methods for controlling a ramp rate of an output voltage derived from one or more charge pumps and reducing variation in the ramp rate due to process, voltage, and temperature (PVT) variations are described. In some embodiments, the ramp rate of the output voltage from one or more charge pumps may be controlled using a ramp rate control circuit that uses a digital counter to adjust (or step up) the output voltage from the one or more charge pumps based on a ramp rate schedule. The ramp rate schedule may specify varying output voltage levels for the one or more charge pumps during a time period in which the output voltage charges up from a first voltage to a second voltage greater than the first voltage.Type: GrantFiled: October 21, 2014Date of Patent: May 16, 2017Assignee: SANDISK TECHNOLOGIES LLCInventors: Qui Vi Nguyen, Steve Choi
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Publication number: 20150213844Abstract: Methods for controlling a ramp rate of an output voltage derived from one or more charge pumps and reducing variation in the ramp rate due to process, voltage, and temperature (PVT) variations are described. In some embodiments, the ramp rate of the output voltage from one or more charge pumps may be controlled using a ramp rate control circuit that uses a digital counter to adjust (or step up) the output voltage from the one or more charge pumps based on a ramp rate schedule. The ramp rate schedule may specify varying output voltage levels for the one or more charge pumps during a time period in which the output voltage charges up from a first voltage to a second voltage greater than the first voltage.Type: ApplicationFiled: October 21, 2014Publication date: July 30, 2015Applicant: SANDISK TECHNOLOGIES INC.Inventors: Qui Vi Nguyen, Steve Choi
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Patent number: 8710907Abstract: A charge pump system is formed on an integrated circuit that can be connected to an external power supply. The system includes a charge pump and a clock generator circuit. The clock circuit is coupled to provide a clock output, at whose frequency the charge pump operates and generates an output voltage from an input voltage. The clock frequency is a decreasing function of the voltage level of the external power supply. This allows for reducing power consumption in the charge pump system formed on a circuit connectable to an external power supply.Type: GrantFiled: June 24, 2008Date of Patent: April 29, 2014Assignee: SanDisk Technologies Inc.Inventors: Qui Vi Nguyen, Feng Pan, Jonathan H. Huynh
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Patent number: 8699247Abstract: A charge pump system can provide multiple regulated output levels, including several concurrently, in an arrangement that can reduce the area and power consumption of such a high voltage generation system. The charge pump system can be dynamically reconfigurable based on output requirements. When output level is low, but required for a large AC, DC load, the system is configured in parallel to share the load. When a higher output is required, such as for a programming in a non-volatile memory, the system is configured in serial to generate the desired high output level. The exemplary embodiment uses all of the pump units in each operation and, hence, is able to be optimized for smaller pump area and less power consumption, while still delivering the same pump ability as larger, more power consuming arrangements.Type: GrantFiled: September 9, 2011Date of Patent: April 15, 2014Assignee: SanDisk Technologies Inc.Inventors: Qui Vi Nguyen, Jonathan Huynh
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Patent number: 8514628Abstract: A charge pump system uses a dynamic switching approach, where the pump connections are independent of the load for each output. One large pump is designed to be shared between all of the outputs for use during the ramp up during recovery, with each output level also have one designated pump to maintain its level when under regulation. Each small pump is designed with capability that can maintain its output at its regulation level. Each of these pumps can be tailored to the corresponding output level, such as the number of stages being higher in the pump to supply the higher output level. The large pump unit is constructed to be ample to provide sufficient drive to be able to assist in the ramp up phase for all of the outputs and has as many switches needed to connect the pump with all the needed outputs.Type: GrantFiled: September 22, 2011Date of Patent: August 20, 2013Assignee: SanDisk Technologies Inc.Inventors: Qui Vi Nguyen, Khin Htoo, Jonathan Huynh
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Publication number: 20130076432Abstract: A regulator system for a charge pump system divides the binary decoding into two branches. One controls a set of parallel connected resistors for fine output voltage steps. The other branch controls a serial resistor to provide the large step size. For example, a 9-bit digital input signal is split into 2 least significant for the fine adjustment and the other 7 bits for the larger adjustments. In the example of a 50 mV step size, in one current path 2 bits of the binary input then control two parallel resistors for 50 mV and 100 mV step size, and in the other current path 7 bits are used for one-hot-decode control serial resistors to provide a 200 mV step size. A unity gain operational amplifier and a high voltage device are added in between the two branches to decouple the parasitic capacitance of large parallel resistors from the other elements.Type: ApplicationFiled: September 22, 2011Publication date: March 28, 2013Inventors: Qui Vi Nguyen, Trung Pham
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Publication number: 20130077411Abstract: A charge pump system uses a dynamic switching approach, where the pump connections are independent of the load for each output. One large pump is designed to be shared between all of the outputs for use during the ramp up during recovery, with each output level also have one designated pump to maintain its level when under regulation. Each small pump is designed with capability that can maintain its output at its regulation level. Each of these pumps can be tailored to the corresponding output level, such as the number of stages being higher in the pump to supply the higher output level. The large pump unit is constructed to be ample to provide sufficient drive to be able to assist in the ramp up phase for all of the outputs and has as many switches needed to connect the pump with all the needed outputs.Type: ApplicationFiled: September 22, 2011Publication date: March 28, 2013Inventors: Qui Vi Nguyen, Khin Htoo, Jonathan Huynh
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Patent number: 8400212Abstract: A regulator system for a charge pump system divides the binary decoding into two branches. One controls a set of parallel connected resistors for fine output voltage steps. The other branch controls a serial resistor to provide the large step size. For example, a 9-bit digital input signal is split into 2 least significant for the fine adjustment and the other 7 bits for the larger adjustments. In the example of a 50 mV step size, in one current path 2 bits of the binary input then control two parallel resistors for 50 mV and 100 mV step size, and in the other current path 7 bits are used for one-hot-decode control serial resistors to provide a 200 mV step size. A unity gain operational amplifier and a high voltage device are added in between the two branches to decouple the parasitic capacitance of large parallel resistors from the other elements.Type: GrantFiled: September 22, 2011Date of Patent: March 19, 2013Assignee: SanDisk Technologies Inc.Inventors: Qui Vi Nguyen, Trung Pham
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Publication number: 20130063118Abstract: A charge pump system can provide multiple regulated output levels, including several concurrently, in an arrangement that can reduce the area and power consumption of such a high voltage generation system. The charge pump system can be dynamically reconfigurable based on output requirements. When output level is low, but required for a large AC, DC load, the system is configured in parallel to share the load. When a higher output is required, such as for a programming in a non-volatile memory, the system is configured in serial to generate the desired high output level. The exemplary embodiment uses all of the pump units in each operation and, hence, is able to be optimized for smaller pump area and less power consumption, while still delivering the same pump ability as larger, more power consuming arrangements.Type: ApplicationFiled: September 9, 2011Publication date: March 14, 2013Inventors: Qui Vi Nguyen, Jonathan Huynh
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Patent number: 8395434Abstract: A level shifter circuit is presented that can apply a negative voltage level to non-selected blocks while still being able to drive a high positive level when selected. An exemplary embodiment presents a negative level shifter that is not susceptible to low voltage pfet breakdown. This allows for a high voltage level shifter (transfer gate) that can drive a negative level for unselected blocks and, when enabled for a selected block, can still drive a positive high voltage level. By using a pair of low voltage PMOS device whose n-wells share the same level as other PMOS transistors in the design, layout area can be minimized. The gates of this pair of PMOSs are connected to VSS, thereby preventing these low voltage PMOS devices from thin oxide breakdown.Type: GrantFiled: October 5, 2011Date of Patent: March 12, 2013Assignee: SanDisk Technologies Inc.Inventors: Qui Vi Nguyen, Takuya Ariki, Jongmin Park
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Patent number: 8228739Abstract: A circuit and corresponding method for providing a reference voltage are presented. The circuit includes a current source having a magnitude with positive temperature correlation connected to a node, and a diode element connected between the node and ground, where the reference voltage is provided from the node. The circuit also includes a variable resistance connected to receive an input indicative of the circuit temperature and through which the diode element is connected to the node. The value of the variable resistance is adjusted based upon the circuit temperature input. The circuit is useful for application as a peripheral circuitry, such as on a flash or other non-volatile memory and other circuits requiring an on-chip reference voltage source.Type: GrantFiled: July 18, 2011Date of Patent: July 24, 2012Assignee: SanDisk Technologies Inc.Inventors: Feng Pan, Yuxin Wang, Jonathan H. Huynh, Albert Chang, Khin Htoo, Qui Vi Nguyen
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Patent number: 8106701Abstract: A level shifter circuit suitable for high voltage applications with shoot-through current isolation is presented. The level shifter receives a first enable signal and receives an input voltage at a first node and supplies an output voltage at a second node. The circuit provides the output voltage from the input voltage in response to the first enable signal being asserted and sets the output node to a low voltage value when the first enable signal is de-asserted. The level shifting circuit includes a depletion type NMOS transistor, having a gate connected to the output node, and a PMOS transistor, having a gate connected to the first enable signal. It also includes a first resistive element that is distinct from the NMOS and PMOS transistors. The NMOS transistor, the PMOS transistor and the first resistive elements are connected in series between the first and second nodes, with the NMOS transistor being connected to the first node.Type: GrantFiled: September 30, 2010Date of Patent: January 31, 2012Assignee: SanDisk Technologies Inc.Inventors: Jonathan Hoang Huynh, Feng Pan, Qui Vi Nguyen, Trung Pham
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Publication number: 20110273227Abstract: A circuit and corresponding method for providing a reference voltage are presented. The circuit includes a current source having a magnitude with positive temperature correlation connected to a node, and a diode element connected between the node and ground, where the reference voltage is provided from the node. The circuit also includes a variable resistance connected to receive an input indicative of the circuit temperature and through which the diode element is connected to the node. The value of the variable resistance is adjusted based upon the circuit temperature input. The circuit is useful for application as a peripheral circuitry, such as on a flash or other non-volatile memory and other circuits requiring an on-chip reference voltage source.Type: ApplicationFiled: July 18, 2011Publication date: November 10, 2011Inventors: Feng Pan, Yuxin Wang, Jonathan H. Huynh, Albert Chang, Khin Htoo, Qui Vi Nguyen
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Patent number: 8004917Abstract: A circuit and corresponding method for providing a reference voltage are presented. The circuit includes a current source having a magnitude with positive temperature correlation connected to a node, and a diode element connected between the node and ground, where the node supplies the reference voltage. The circuit also includes a variable resistance connected to receive an input indicative of the circuit temperature and through which the diode element is connected to the node. The value of the variable resistance is adjusted based upon the circuit temperature input. The circuit is useful for application as a peripheral circuitry, such as on a flash or other non-volatile memory and other circuits requiring an on-chip reference voltage source.Type: GrantFiled: September 22, 2008Date of Patent: August 23, 2011Assignee: SanDisk Technologies Inc.Inventors: Feng Pan, Yuxin Wang, Jonathan H. Huynh, Albert Chang, Khin Htoo, Qui Vi Nguyen
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Publication number: 20100074033Abstract: A circuit and corresponding method for providing a reference voltage are presented. The circuit includes a current source having a magnitude with positive temperature correlation connected to a node, and a diode element connected between the node and ground, where the reference voltage is provided from the node. The circuit also includes a variable resistance connected to receive an input indicative of the circuit temperature and through which the diode element is connected to the node. The value of the variable resistance is adjusted based upon the circuit temperature input. The circuit is useful for application as a peripheral circuitry, such as on a flash or other non-volatile memory and other circuits requiring an on-chip reference voltage source.Type: ApplicationFiled: September 22, 2008Publication date: March 25, 2010Inventors: Feng Pan, Yuxin Wang, Jonathan H. Huynh, Albert Chang, Khin Htoo, Qui Vi Nguyen
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Patent number: 7683700Abstract: A charge pump system for supplying an output voltage to a load is described. It includes a regulation circuit connected to receive the output voltage and derive an enable signal from it and multiple charge pump circuits connected in parallel to supply the output voltage. Each of the charge pump circuits is also connected to receive a clock signal and the enable signal. The system also includes one or more delay circuit elements, where a corresponding one or more, but less than all, of the charge pump circuits are connectable to receive the enable signal delayed by the corresponding delay circuit element.Type: GrantFiled: June 25, 2008Date of Patent: March 23, 2010Assignee: SanDisk CorporationInventors: Jonathan H. Huynh, Qui Vi Nguyen, Feng Pang