Patents by Inventor Hung Pham Le
Hung Pham Le 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: 20240070400Abstract: Method of analysis text message syntactically and by content, which entails: step 1; Split syntaxes (made available to subscribers by the network operator) into tokens to store in a Syntax Trie; step 2. Pre-process an incoming text from a subscriber; step 3. Split the text (pre-processed in Step 2) into tokens; step 4. Look up paths that include the tokens (obtained in Step 3) in the Syntax Trie (initialized in Step 1); step 5: Return the look-up result, which is the path in the Syntax Trie that best reflects the user intent.Type: ApplicationFiled: August 30, 2023Publication date: February 29, 2024Applicant: VIETTEL GROUPInventors: Van Chung Trinh, Duc Hai Nguyen, Dinh Hung Nguyen, Hai Son Bui, Duc Anh Nguyen, Thi Huyen Trang Nguyen, Thi Thuy Linh Le, Van Chinh Pham, Van Manh Phan
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Patent number: 8098090Abstract: An open-drain output buffer is operative to sustain relatively high voltages applied to an output pad. The open-drain buffer includes a number of floating wells, output switching devices and corresponding well-bias selectors to ensure that no gate oxide sustains voltages greater than a predefined value. PMOS and NMOS well-bias selectors operate to select and provide an available highest or lowest voltage, respectively, to bias corresponding well-regions and ensure no device switching terminals are electrically over stressed. As output related terminals experience switching related voltage excursions, the well-bias selectors select alternate terminals to continue selection of the respective highest or lowest voltages available and provide correct well-biasing conditions. Voltage dividers are incorporated to generate well-biasing control voltages.Type: GrantFiled: February 3, 2010Date of Patent: January 17, 2012Assignee: Exar CorporationInventor: Hung Pham Le
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Patent number: 7969697Abstract: An electrostatic discharge protection device is disposed between true-complement input pins of a differential signal pair and a ground node. A common node couples the three diode stacks together. A first and a second diode stack each connect to one of the differential signal pair input pins. The third diode stack couples to the ground node. Each of the diode stacks is fabricated by a pair of high concentration p-type contact dopant regions within a low concentration n-well region. Each of the p-type contact dopant regions is configured to form back-to-back diodes connected in series with cathodes in common. In protecting common mode receivers, current from an ESD event is channeled to ground rather than to the complementary receiver node. The diode stacks are capable of withstanding a 15 kV incident and save up to 25% in area compared to a fully parallel configuration for differential signal pairs.Type: GrantFiled: April 22, 2008Date of Patent: June 28, 2011Assignee: Exar CorporationInventors: Bahman Farzan, Hung Pham Le
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Patent number: 7773357Abstract: An auto-detecting input circuit is operative to sustain relatively high voltages applied to an input pad and generate corresponding signal levels at a native supply voltage range. The input circuit includes floating wells, corresponding bias selectors, and input biasing transistors to ensure that no gate oxide exposed to external voltages sustains a voltage greater than a predefined value. Bias selectors select an available highest voltage to reverse bias corresponding floating wells and ensure transistors are not electrically overstressed. As input-related terminals experience switching related voltages, the bias selectors select alternate terminals to continue selection of the highest voltage available and provide correct reverse biasing conditions. A resistor and clamp generate translated output voltage levels limited to the native supply voltage range. A latch is triggered by a first input signal excursion above the native supply voltage.Type: GrantFiled: January 14, 2008Date of Patent: August 10, 2010Assignee: Exar CorporationInventor: Hung Pham Le
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Publication number: 20100127762Abstract: An open-drain output buffer is operative to sustain relatively high voltages applied to an output pad. The open-drain buffer includes a number of floating wells, output switching devices and corresponding well-bias selectors to ensure that no gate oxide sustains voltages greater than a predefined value. PMOS and NMOS well-bias selectors operate to select and provide an available highest or lowest voltage, respectively, to bias corresponding well-regions and ensure no device switching terminals are electrically over stressed. As output related terminals experience switching related voltage excursions, the well-bias selectors select alternate terminals to continue selection of the respective highest or lowest voltages available and provide correct well-biasing conditions. Voltage dividers are incorporated to generate well-biasing control voltages.Type: ApplicationFiled: February 3, 2010Publication date: May 27, 2010Applicant: Exar CorporationInventor: Hung Pham Le
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Patent number: 7683696Abstract: An open-drain output buffer is operative to sustain relatively high voltages applied to an output pad. The open-drain buffer includes a number of floating wells, output switching devices and corresponding well-bias selectors to ensure that no gate oxide sustains voltages greater than a predefined value. PMOS and NMOS well-bias selectors operate to select and provide an available highest or lowest voltage, respectively, to bias corresponding well-regions and ensure no device switching terminals are electrically over stressed. As output related terminals experience switching related voltage excursions, the well-bias selectors select alternate terminals to continue selection of the respective highest or lowest voltages available and provide correct well-biasing conditions. Voltage dividers are incorporated to generate well-biasing control voltages.Type: GrantFiled: December 26, 2007Date of Patent: March 23, 2010Assignee: Exar CorporationInventor: Hung Pham Le
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Publication number: 20090262474Abstract: An electrostatic discharge protection device is disposed between true-complement input pins of a differential signal pair and a ground node. A common node couples the three diode stacks together. A first and a second diode stack each connect to one of the differential signal pair input pins. The third diode stack couples to the ground node. Each of the diode stacks is fabricated by a pair of high concentration p-type contact dopant regions within a low concentration n-well region. Each of the p-type contact dopant regions is configured to form back-to-back diodes connected in series with cathodes in common. In protecting common mode receivers, current from an ESD event is channeled to ground rather than to the complementary receiver node. The diode stacks are capable of withstanding a 15 kV incident and save up to 25% in area compared to a fully parallel configuration for differential signal pairs.Type: ApplicationFiled: April 22, 2008Publication date: October 22, 2009Applicant: Exar CorporationInventors: Bahman Farzan, Hung Pham Le
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Publication number: 20090180227Abstract: An auto-detecting input circuit is operative to sustain relatively high voltages applied to an input pad and generate corresponding signal levels at a native supply voltage range. The input circuit includes floating wells, corresponding bias selectors, and input biasing transistors to ensure that no gate oxide exposed to external voltages sustains a voltage greater than a predefined value. Bias selectors select an available highest voltage to reverse bias corresponding floating wells and ensure transistors are not electrically overstressed. As input-related terminals experience switching related voltages, the bias selectors select alternate terminals to continue selection of the highest voltage available and provide correct reverse biasing conditions. A resistor and clamp generate translated output voltage levels limited to the native supply voltage range. A latch is triggered by a first input signal excursion above the native supply voltage.Type: ApplicationFiled: January 14, 2008Publication date: July 16, 2009Applicant: Exar CorporationInventor: Hung Pham Le
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Patent number: 7012794Abstract: An analog transfer gate that can be connected to an external line of a chip that is also connected to a digital circuit. The transfer gate includes both NMOS and PMOS transistors for passing the analog signals in both directions. A voltage sensing circuit is connected to the external line and is configured to sense a voltage that is higher than the supply voltage of the analog circuit. When this occurs, it produces a sense output signal. The sense output signal activates a protection enabling circuit that turns off the PMOS and NMOS transistors. In addition, at least one additional protection transistor is activated to avoid too high of a voltage being applied across any of the transistor junctions.Type: GrantFiled: January 17, 2003Date of Patent: March 14, 2006Assignee: Exar CorporationInventor: Hung Pham Le
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Publication number: 20040141273Abstract: An analog transfer gate that can be connected to an external line of a chip that is also connected to a digital circuit. The transfer gate includes both NMOS and PMOS transistors for passing the analog signals in both directions. A voltage sensing circuit is connected to the external line and is configured to sense a voltage that is higher than the supply voltage of the analog circuit. When this occurs, it produces a sense output signal. The sense output signal activates a protection enabling circuit that turns off the PMOS and NMOS transistors. In addition, at least one additional protection transistor is activated to avoid too high of a voltage being applied across any of the transistor junctions.Type: ApplicationFiled: January 17, 2003Publication date: July 22, 2004Applicant: Exar CorporationInventor: Hung Pham Le
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Patent number: 6501320Abstract: A rectifier circuit with a transistor having first and second electrodes coupled between an input and output of the rectifier circuit. A latch has an output connected to a control node of the transistor, and has first and second inputs connected to the input and output of the rectifier circuit, respectively. The invention provides a self-contained, self-powered, self-regulated low turn-on voltage diode-rectifier with maximum current (on-state conductance) when forward-biased. This circuit can be inserted between any two nodes and behaves like a Schottky diode.Type: GrantFiled: July 25, 2000Date of Patent: December 31, 2002Assignee: Exar CorporationInventor: Hung Pham Le
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Patent number: 6452248Abstract: A programmable fuse structure using an MOS transistor. A voltage potential is switched across the gate of the MOS transistor, with the gate resistance causing it to heat the MOS structure. This causes a short at one or more of a number of locations in the MOS structure, thereby programming the MOS transistor. A programming circuit with the MOS transistor in a feedback path is provided. This feedback provides a self-timing feature, such that immediately after the fuse is programmed, its programming operation ceases.Type: GrantFiled: August 14, 2000Date of Patent: September 17, 2002Assignee: Exar CorporationInventor: Hung Pham Le
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Patent number: 6424510Abstract: The present invention provides an ESD structure that can tolerate voltages at the I/O pin, or pad, higher than the voltage allowed for such technology. More particularly, the present invention provides an electrostatic discharge integrated circuit having a first and second NMOS transistor, a first and second voltage divider, a first and second steady state biasing circuit. The first NMOS transistor sinks electrostatic discharge current from an input/output pad to a ground source, the first NMOS transistor having a drain coupled to the input/output pad, and a gate. The first voltage divider has a node connected to the gate of the first NMOS transistor. The first steady state biasing circuit connects to the gate of the first NMOS transistor. The second NMOS transistor sinks electrostatic discharge current from the input/output pad to the ground source, the second NMOS transistor having a drain coupled to a source of the first NMOS transistor, and a source coupled to the ground source.Type: GrantFiled: April 28, 2000Date of Patent: July 23, 2002Assignee: Exar CorporationInventors: Janardhanan S. Ajit, Hung Pham Le
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Patent number: 6313672Abstract: The present invention provides a buffer circuit that can tolerate over-voltage, and a method for protecting buffer circuits from over-voltage. Specifically, the buffer circuit can operate at lower voltages (e.g., 3.3 V) and interface with other circuits that operate at higher voltages (e.g., 5 V). In a preferred embodiment, the buffer circuit has a pre-driver circuit having a pull-up circuit coupled to an interface node via a PMOS switch transistor. The pre-driver biasing circuit is configured to decouple the pull-up circuit from the input voltage source when an input voltage at the interface node exceeds the VDD voltage by a threshold voltage. The buffer circuit has a first biasing transistor that ties an N-well of the integrated circuit to the VDD voltage source when a control node of a PMOS driver transistor is in a first logic state, and a second biasing transistor that ties the N-well to the VDD voltage source when the control node of the PMOS driver transistor is in a second logic state.Type: GrantFiled: December 15, 1999Date of Patent: November 6, 2001Assignee: Exar CorporationInventors: Janardhanan S. Ajit, Hung Pham Le
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Patent number: 6313671Abstract: The present invention provides a buffer circuit that consumes little power. Specifically, the buffer circuit can operate at lower voltages (e.g., 3.3 V) and interface with other circuits that operate at higher voltages (e.g., 5 V) at an interface node. In a preferred embodiment, the buffer circuit has a driver PMOS transistor, and a pre-driver circuit having a pull-up circuit coupled to the interface node via a PMOS switch transistor and a first PMOS pass transistor. The pre-driver biasing circuit is configured to decouple the pull-up circuit from the interface node when an input voltage at the interface node exceeds the VDD voltage by a PMOS threshold voltage.Type: GrantFiled: December 15, 1999Date of Patent: November 6, 2001Assignee: Exar CorporationInventors: Hung Pham Le, Janardhanan S. Ajit
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Patent number: 6063659Abstract: A high-precision, linear MOS-transistor-gate capacitor device is provided by applying a source/drain high-energy, high-dose ion implantation through implant windows in a polysilicon top plate of the capacitor. The ion implantation may be a step of generic MOS source/drain process flow.Type: GrantFiled: September 4, 1997Date of Patent: May 16, 2000Inventor: Hung Pham Le