Patents by Inventor Uei-Shan Uang
Uei-Shan Uang 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: 7834610Abstract: A bandgap reference circuit includes a reference current generator for respectively generating a first reference current on a first current path and a second reference current on a second current path, a current mirror for generating a third reference current on a third current path based on the first and second reference currents, an operation amplifier for rendering the first reference current substantially identical to the second reference current and a feedback circuit for rendering a node voltage on the first current path substantially identical to another node voltage on the third current path, so as to eliminate possible errors caused by a channel length modulation effect in the current mirror.Type: GrantFiled: June 1, 2007Date of Patent: November 16, 2010Assignee: Faraday Technology Corp.Inventors: Yan-Hua Peng, Uei-Shan Uang, Mei-Show Chen
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Patent number: 7679352Abstract: A bandgap reference circuit comprises: a current generator for generating an output current, the current generator comprising a first reference unit and a plurality of second reference units arranged in parallel, where the current generator is capable of determining the magnitude of the output current according to the reference units; a first resistor, coupled between a first terminal of the first reference unit and a node, for transmitting a first current; a second resistor, coupled to the node and a first terminal of each second reference unit, for transmitting a second current; a third resistor, coupled between the node and an output terminal of the bandgap reference circuit, for transmitting a third current; and a current-to-voltage converter, coupled to the third resistor, for generating a bandgap voltage according to the output current and the third current.Type: GrantFiled: May 30, 2007Date of Patent: March 16, 2010Assignee: Faraday Technology Corp.Inventors: Yan-Hua Peng, Uei-Shan Uang
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Publication number: 20090051342Abstract: A bandgap reference circuit includes an input circuit having a first FET, a second FET, and a first resistor, wherein a first node is connected to the first FET having a first threshold voltage, the first resistor is connected between a second node and the second FET having a second threshold voltage; a mirroring circuit for controlling two output currents respectively derived from the first and second nodes, and maintaining the two output currents to a specific current ratio; and an operation amplifier connected to the first node, the second node of the input circuit, and the mirroring circuit, for controlling two voltages respectively at the first and second nodes of the input circuit to a specific voltage ratio; wherein the first FET and the second FET are both operating in the subthreshold region, the first threshold voltage is larger than the second threshold voltage, and the two output currents are independent of temperature.Type: ApplicationFiled: August 20, 2008Publication date: February 26, 2009Applicant: FARADAY TECHNOLOGY CORPORATIONInventors: YAN-HUA PENG, UEI-SHAN UANG, CHIA-WEI CHANG
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Publication number: 20090051341Abstract: A bandgap reference circuit includes a PTAT current generating circuit for generating a PTAT current; a CTAT circuit generating circuit for generating a CTAT current; a node for receiving the PTAT current and the CTAT current; and, a first resistor connected between the node and a ground, wherein a reference voltage is derived from the first resistor when a superposed current of the PTAT current and the CTAT current is flowing through the first resistor.Type: ApplicationFiled: August 1, 2008Publication date: February 26, 2009Applicant: FARADAY TECHNOLOGY CORPORATIONInventors: CHIA-WEI CHANG, UEI-SHAN UANG, YAN-HUA PENG
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Patent number: 7495505Abstract: A low supply voltage band-gap reference circuit is provided, which includes a positive temperature coefficient current generation unit and a negative temperature coefficient current generation unit, and it is implemented by way of current summing. Through the current-mode temperature compensation technique, the present invention is able to reduce the voltage headroom and the number of operational amplifiers required by the conventional voltage-summing method, as well as the influence to the output voltage due to the offset voltage, thereby providing a stable and low voltage band-gap reference voltage level. In addition, by reducing the number of operational amplifiers and resistors of high resistance, the circuit area is reduced, and chip cost is saved.Type: GrantFiled: July 18, 2006Date of Patent: February 24, 2009Assignee: Faraday Technology Corp.Inventors: Kuen-Shan Chang, Uei-Shan Uang, Mei-Show Chen, Chia-Ming Hong
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Publication number: 20080297130Abstract: A bandgap reference circuit comprises: a current generator for generating an output current, the current generator comprising a first reference unit and a plurality of second reference units arranged in parallel, where the current generator is capable of determining the magnitude of the output current according to the reference units; a first resistor, coupled between a first terminal of the first reference unit and a node, for transmitting a first current; a second resistor, coupled to the node and a first terminal of each second reference unit, for transmitting a second current; a third resistor, coupled between the node and an output terminal of the bandgap reference circuit, for transmitting a third current; and a current-to-voltage converter, coupled to the third resistor, for generating a bandgap voltage according to the output current and the third current.Type: ApplicationFiled: May 30, 2007Publication date: December 4, 2008Inventors: Yan-Hua Peng, Uei-Shan Uang
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Publication number: 20080297131Abstract: A bandgap reference circuit includes a reference current generator for respectively generating a first reference current on a first current path and a second reference current on a second current path, a current mirror for generating a third reference current on a third current path based on the first and second reference currents, an operation amplifier for rendering the first reference current substantially identical to the second reference current and a feedback circuit for rendering a node voltage on the first current path substantially identical to another node voltage on the third current path, so as to eliminate possible errors caused by a channel length modulation effect in the current mirror.Type: ApplicationFiled: June 1, 2007Publication date: December 4, 2008Applicant: FARADAY TECHNOLOGY CORP.Inventors: Yan-Hua Peng, Uei-Shan Uang, Mei-Show Chen
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Patent number: 7411380Abstract: A non-linearity compensation circuit and a bandgap reference circuit using the same for compensating non-linear effects of a reference voltage are provided. In the non-linearity compensation circuit, the reference voltage is transformed into a temperature independent current. A current mirror mirrors the temperature independent current for biasing a bipolar junction transistor (BJT). Further, two resistors are used for estimating a non-linear voltage, so as to compensate the reference voltage.Type: GrantFiled: July 21, 2006Date of Patent: August 12, 2008Assignee: Faraday Technology Corp.Inventors: Kuen-Shan Chang, Uei-Shan Uang
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Publication number: 20080094130Abstract: A supply-independent biasing circuit applied to a bandgap reference circuit or a proportional to absolute temperature (PTAT) current generating circuit. The bandgap reference circuit or the PTAT current generating circuit includes a mirroring circuit, an operation amplifier, and an input circuit. The mirroring circuit including a plurality of first type FETs. The operation amplifier includes a first type FET connecting to a current input terminal of the operation amplifier. And, the supply-independent biasing circuit includes a first type FET having a gate connected to gates of the first type FETs in the mirroring circuit and having a drain acted as an output current path; and, a current mirror including a plurality of second type FETs and having a current receiving terminal connected to the output current path and having a current outputting terminal connected to the current input terminal of the operation amplifier.Type: ApplicationFiled: May 21, 2007Publication date: April 24, 2008Applicant: FARADAY TECHNOLOGY CORPORATIONInventors: Uei-Shan Uang, Shih-Hsuan Hsu, Yan-Hua Peng
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Publication number: 20080018319Abstract: A low supply voltage band-gap reference circuit is provided, which includes a positive temperature coefficient current generation unit and a negative temperature coefficient current generation unit, and it is implemented by way of current summing. Through the current-mode temperature compensation technique, the present invention is able to reduce the voltage headroom and the number of operational amplifiers required by the conventional voltage-summing method, as well as the influence to the output voltage due to the offset voltage, thereby providing a stable and low voltage band-gap reference voltage level. In addition, by reducing the number of operational amplifiers and resistors of high resistance, the circuit area is reduced, and chip cost is saved.Type: ApplicationFiled: July 18, 2006Publication date: January 24, 2008Inventors: Kuen-Shan Chang, Uei-Shan Uang, Mei-Show Chen, Chia-Ming Hong
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Publication number: 20080018316Abstract: A non-linearity compensation circuit and a bandgap reference circuit using the same for compensating non-linear effects of a reference voltage are provided. In the non-linearity compensation circuit, the reference voltage is transformed into a temperature independent current. A current mirror mirrors the temperature independent current for biasing a bipolar junction transistor (BJT). Further, two resistors are used for estimating a non-linear voltage, so as to compensate the reference voltage.Type: ApplicationFiled: July 21, 2006Publication date: January 24, 2008Inventors: Kuen-Shan Chang, Uei-Shan Uang
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Patent number: 7301321Abstract: A voltage reference circuit including a positive temperature coefficient current generator, a negative temperature coefficient current generator, and a first resistor is provided. In the positive temperature coefficient current generator, two transistors are operated in the weak inversion region, and a second resistor is connected in series between the gates of the two transistors. The second resistor employs the characteristic that a transistor operated in weak inversion region acts like a bipolar junction transistor to generate a positive temperature coefficient current. The negative temperature coefficient current generator generates a negative temperature coefficient current in response to a negative temperature coefficient voltage drop on a third resistor. The positive temperature coefficient current and the negative temperature coefficient current flow through the first resistor together, thus producing a stable reference voltage.Type: GrantFiled: September 6, 2006Date of Patent: November 27, 2007Assignee: Faraday Technology Corp.Inventors: Uei-Shan Uang, Kuen-Shan Chang, Mei-Show Chen