To Derive A Voltage Reference (e.g., Band Gap Regulator) Patents (Class 323/313)
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Publication number: 20150002130Abstract: A simple bandgap current generator combines a PTAT (proportional to absolute temperature) base-emitter voltage (VBE) measured across two binary junction devices (?VBE=VBE1-VBE2) with a current that is varied by an nWell resistor with a positive temperature coefficient to produce a CTAT (complementary to absolute temperature) current instead of PTAT reference current. One of the base-emitter voltages is constrained to be VBE1=VBE(1-?T). This reduces the temperature dependency of a reference current generated by the bandgap generator. This reference current may be used to generate a bandgap reference voltage by adding an IR drop to a diode voltage or to a base-emitter voltage. The simple bandgap circuit is significantly smaller in size than a precision bandgap circuit, but still provides a voltage and/or a current reference signal having a good accuracy.Type: ApplicationFiled: June 27, 2013Publication date: January 1, 2015Inventors: Ajay Kumar, Rahul Bhandarkar
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Patent number: 8922273Abstract: A semiconductor device is capable of generating an internal voltage having a voltage level that is dependent on an external power supply voltage. The semiconductor device includes an internal voltage generation unit configured to generate a plurality of internal voltages having different voltage levels by using an external power supply voltage, a voltage level detection unit configured to detect a voltage level of the external power supply voltage, and a selection unit configured to selectively output one of the internal voltages in response to a detection result of the voltage level detection unit.Type: GrantFiled: June 30, 2009Date of Patent: December 30, 2014Assignee: SK Hynix Inc.Inventors: Hyoung-Jun Na, Kyung-Whan Kim
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Patent number: 8907651Abstract: An electronic circuit includes a switchable circuit domain that operates in a RUN mode and a STANDBY mode and receives a supply current from a core power supply. A power regulator is connected between the core power supply and the switchable circuit domain to regulate the supply current provided to the switchable circuit domain when the electronic circuit is in the RUN mode. A capacitor is connected between the power regulator and ground and is charged by a refresh circuit when the electronic circuit is in the STANDBY mode. The refresh circuit maintains a voltage across the capacitor when the electronic circuit is in the standby mode, which reduces the time for the electronic circuit to transition from the STANDBY mode to the RUN mode.Type: GrantFiled: February 9, 2012Date of Patent: December 9, 2014Assignee: Freescale Semiconductor, Inc.Inventors: Morthala V Narsi Reddy, Kushal Kamal, Samaksh Sinha
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Patent number: 8907653Abstract: Disclosed herein are a circuit of outputting a temperature compensation power voltage from variable power and a method thereof, the circuit including: a regulator circuit unit converting the variable power into a predetermined voltage desired by a system; a resistance compensation circuit unit provided at an output terminal of the regulator circuit unit, and compensating for a change in resistance value due to the temperature change; and a temperature sensor sensing a change in surrounding temperature of an electronic circuit system employing the regulator circuit unit and supplying an output value corresponding to the sensed temperature change to the resistance compensation circuit unit, to thereby allow the resistance compensation circuit unit to compensate for the change in resistance value due to the temperature change.Type: GrantFiled: March 14, 2013Date of Patent: December 9, 2014Assignee: Samsung Electro-Mechanics Co., Ltd.Inventor: Soo Woong Lee
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Patent number: 8907652Abstract: A generator of a voltage logarithmically variable with temperature may include a differential amplifier having a pair of transistors, each coupled with a respective bias network adapted to bias in a conduction state the transistors first and second respectively with a constant current and with a current proportional to the working absolute temperature. The pair of transistors may generate between their control nodes the voltage logarithmically variable with temperature. The differential amplifier may have a common bias current generator coupled between the common terminal of the differential pair of transistors and a node at a reference potential, and a feedback line to provide a path for the current difference between the sum of currents flowing through the transistors of the differential pair and the common bias current.Type: GrantFiled: April 4, 2012Date of Patent: December 9, 2014Assignee: STMicroelectronics S.R.L.Inventors: Sergio Lecce, Maurizio Rossi
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Publication number: 20140354260Abstract: An integrated circuit includes a node setting block connected to a reference node and suitable for setting a voltage level of the reference node to a reference voltage level, a plurality of control voltage generation units connected in series to a reference node and suitable for generating a plurality of control voltages of which voltage level is variable and a current sensing circuit suitable for sensing a variation of a current flowing through a signal transmission line by using the plurality of control voltages, the signal transmission line connected to an internal circuit and a voltage level of the signal transmission line being fixed.Type: ApplicationFiled: December 16, 2013Publication date: December 4, 2014Applicant: SK hynix Inc.Inventor: Jae-Kwan KWON
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Publication number: 20140354259Abstract: A bandgap reference voltage generating circuit for providing a reference voltage is disclosed. The bandgap reference voltage generating circuit includes four-terminal current source circuit, a regulator circuit and a temperature-compensating circuit. The four-terminal current source circuit outputs a first voltage, a second voltage and a first current which are independent of variation of a first system voltage. The regulator circuit receives the first voltage and the second voltage and when the first system voltage is larger than a threshold voltage value, the regulator circuit outputs the reference voltage independent of variation of the first system voltage via voltage-difference between the first voltage and the second voltage. The temperature-compensating circuit receives the first current and compensates a temperature curve of the reference voltage outputted from the regulator circuit.Type: ApplicationFiled: September 3, 2013Publication date: December 4, 2014Applicant: ADVANCED SEMICONDUCTOR ENGINEERING INC.Inventors: JAW-MING DING, HSIN-CHIN CHANG
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Publication number: 20140340068Abstract: A bandgap reference circuit is provided and which includes an operating voltage, a current mirror, a first p-channel metal-oxide semiconductor (PMOS) transistor and an amplifier. The current mirror is coupled to the operating voltage. The first PMOS transistor is coupled to the operating voltage and the current mirror. The amplifier is coupled to the current mirror and the first PMOS transistor. When the bandgap reference circuit is activated, the operating voltage starts to supply voltage such that the first PMOS transistor is turned on first. When the operating voltage is higher than a preset voltage level, the first PMOS transistor is turned off, in order to complete an start-up process.Type: ApplicationFiled: January 27, 2014Publication date: November 20, 2014Applicant: uPI Semiconductor Corp.Inventor: Wen-Sheng Lin
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Patent number: 8891267Abstract: A circuit arrangement with standby mode minimizing power and/or current consumption having a mains AC power supply terminals and an active circuit capable of converting said mains AC power to lower voltage DC levels for operating in an active mode or in a standby mode as required by an appliance such that the selection of the current sensing resistor value for said current sensing resistor limits the maximum peak current through the FET so that the current sensing resistor arrangement is capable of providing significant increases in a steeper rise time of the current at around mains AC power supply zero crossing, so that current is pulled high while the mains AC power supply voltage is low.Type: GrantFiled: August 31, 2011Date of Patent: November 18, 2014Assignee: Hendon Semiconductors Pty. Ltd.Inventors: Paul Bourne, Philip Tracy, David Murfett
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Patent number: 8884600Abstract: A variable reference voltage generation unit used in DC/DC converter includes a sample-hold valley inductor current unit electrically connected to a reference voltage generation unit. The sample-hold valley inductor current unit receives the valley inductor current and converts it into the valley voltage. The reference voltage generation unit receives and converts a current signal two times of a designated current into a voltage signal two times of a designated voltage. The voltage signal two times of reference voltage is then subtracted by the valley voltage to produce the new reference voltage to compare with an inductor voltage for controlling the switching of a switching transistor of the DC/DC convertor.Type: GrantFiled: December 13, 2011Date of Patent: November 11, 2014Assignee: Alpha & Omega Semiconductor, Inc.Inventor: Yung-I Chang
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Patent number: 8884603Abstract: A reference power supply circuit includes an adjustable resistance network and a bandgap reference power supply circuit, in which the adjustable resistance network includes a first resistor end and a second resistor end, the resistance between the first resistor end and the second resistor end varies with a process deviation; the bandgap reference power supply circuit connects the first resistor end with the second resistor end, for generating a positive proportional to absolute temperature current flowing through the first resistor end and the second resistor end and for outputting a reference voltage related to the positive proportional to absolute temperature current. The reference power supply circuit has the advantageous of high precision and good temperature drift characteristic.Type: GrantFiled: November 29, 2011Date of Patent: November 11, 2014Assignees: CSMC Technologies FAB1 Co., Ltd., CSMC Technologies FAB2 Co., Ltd.Inventor: Liang Cheng
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Patent number: 8884601Abstract: In accordance with an embodiment, a reference voltage generator includes a first current generator and a second current generator. The first current generator is configured to produce a first current proportional to a current through a first diode connected in series with the first resistance coupled between a first voltage and a second voltage, such that the first current is produced according to a first proportionality constant. The second current generator is configured to produce a second current proportional to a current through a second diode connected in series with the second resistance coupled between the first voltage and the second voltage, such that the second current is produced according to a second proportionality constant. The reference voltage generator further includes a reference resistor coupled to the first and second current generators and to and output of the reference voltage generator.Type: GrantFiled: December 29, 2011Date of Patent: November 11, 2014Assignee: STMicroelectronics International N.V.Inventors: Saurabh Saxena, Vivek Verma
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Patent number: 8884642Abstract: A circuit having an external test voltage includes an amplifier, a first P-type metal-oxide-semiconductor transistor, a second P-type metal-oxide-semiconductor transistor, at least one reference resistor, at least one test resistor, a first upper resistor, a second upper resistor and a lower resistor. The second P-type metal-oxide-semiconductor transistor is the same as the first P-type metal-oxide-semiconductor transistor. A difference between a voltage of a test output terminal of each test resistor and a voltage of a reference output terminal of a corresponding reference resistor is kept at a predetermined value by duplicating a current flowing through the first P-type metal-oxide-semiconductor transistor to the second P-type metal-oxide-semiconductor transistor, and feeding an external test voltage to a second terminal of the second upper resistor.Type: GrantFiled: January 3, 2012Date of Patent: November 11, 2014Assignee: Etron Technology, Inc.Inventors: Yen-An Chang, Po-Ching Wu
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Patent number: 8884602Abstract: A constant current flowing through a first depletion transistor whose gate and source are connected to each other is caused to flow through a second depletion transistor having the same threshold as the first depletion transistor, to thereby generate a first voltage between a gate and a source of the second depletion transistor. The constant current of the first depletion transistor and a constant current flowing through a third depletion transistor whose gate and source are connected to each other are caused to flow through a fourth depletion transistor. A threshold of the fourth depletion transistor is the same as that of the third depletion transistor but different from that of the first depletion transistor, and hence a second voltage is generated between a gate and a source of the fourth depletion transistor. A reference voltage is generated based on a voltage difference between the first and second voltages.Type: GrantFiled: February 28, 2013Date of Patent: November 11, 2014Assignee: Seiko Instruments Inc.Inventor: Fumiyasu Utsunomiya
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Patent number: 8878512Abstract: A reference current output device and reference current output method that may adjust a reference current while maintaining a temperature gradient. In the reference current output device and reference current output method of the present invention, a reference current is outputted by a reference voltage and current output circuit, a reference voltage outputted from the reference voltage and current output circuit is converted to an adjustment current and outputted by a conversion and output circuit, the adjustment current is superimposed with the reference current and a superimposed current is outputted by a superimposition and output section.Type: GrantFiled: December 2, 2011Date of Patent: November 4, 2014Assignee: Lapis Semiconductor Co., Ltd.Inventor: Mamoru Kondo
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Patent number: 8878511Abstract: A circuit includes a first current path comprising a first floating-gate transistor having a programmable threshold voltage, a second current path, and a differential amplifier. The second current path includes a second floating-gate transistor having a programmable threshold voltage and a resistor. The differential amplifier includes a first input coupled to the first current path, a second input coupled to the second current path, and an output configured to control a reference current path.Type: GrantFiled: February 4, 2010Date of Patent: November 4, 2014Assignee: Semiconductor Components Industries, LLCInventors: Radu H. Iacob, Alexandra-Oana Petroianu
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Patent number: 8860392Abstract: A semiconductor device includes a voltage generating circuit, a first switch, and a charging circuit. The voltage generating circuit generates a voltage for output and has a function to adjust a magnitude of the voltage to be generated. A first switch has a first conduction terminal and a second conduction terminal that are brought into conduction with each other in an ON state, and the first conduction terminal is connected to an output node of the voltage generating circuit via a first line. The charging circuit charges a second line connected to the second conduction terminal of the first switch.Type: GrantFiled: February 7, 2012Date of Patent: October 14, 2014Assignee: Renesas Electronics CorporationInventors: Hiromu Kinoshita, Shinsuke Yoshimura, Akira Suzuki, Akira Oizumi, Soichi Kobayashi
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Patent number: 8853964Abstract: A system including a first transistor, a second transistor, and a comparator. The first transistor is configured to supply a first current to a first load connected to a first terminal of the first transistor. The second transistor is configured to supply a second current to a second load connected to a first terminal of the second transistor, wherein the first current and the second current have a predetermined ratio. The comparator is configured to compare a voltage at the first terminal of the first transistor or a voltage at the first terminal of the second transistor to a reference voltage, and to adjust, based on the comparison, biasing of the first transistor and the second transistor to maintain the predetermined ratio between the first current and the second current.Type: GrantFiled: December 14, 2012Date of Patent: October 7, 2014Assignee: Marvell World Trade Ltd.Inventors: Sehat Sutardja, Ravishanker Krishnamoorthy
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Publication number: 20140285175Abstract: A reference voltage generating circuit comprising a first bandgap voltage source arranged to output a first bandgap voltage exhibiting a first type deviation in response to a strain applied at die level in a given direction; a second bandgap voltage source arranged to output a second bandgap voltage exhibiting a second type deviation in response to a strain applied at die level in the given direction, said second type deviation being opposite to the first type deviation of the first bandgap voltage; and an adding circuit arranged to add the first bandgap voltage and the second bandgap voltage, and to output a temperature drift and strain drift compensated reference voltage.Type: ApplicationFiled: November 4, 2011Publication date: September 25, 2014Applicant: FREESCALE SEMICONDUCTOR, INC.Inventor: Jean Lasseuguette
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Publication number: 20140286091Abstract: A semiconductor integrated circuit includes a reference voltage generation circuit configured to generate a reference voltage, and a voltage changing circuit configured to generate a second voltage from a first voltage based on a difference between the second voltage and the reference voltage and apply the second voltage to a load capacitance. The reference voltage generation circuit includes a variable current source and a capacitor which are connected in series and is configured to change the reference voltage linearly.Type: ApplicationFiled: August 30, 2013Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masafumi UEMURA, Masaru KOYANAGI, Masahiro YOSHIHARA
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Publication number: 20140266140Abstract: A voltage generator is provided which is reliable, self starting and only requires a few components. The voltage generator comprises a first stage that provides a current to a second stage. The first stage has a temperature coefficient of one sign, such as positive, and the second stage has an opposing temperature coefficient, e.g. negative. The responses are summed such that the overall temperature coefficient is reduced.Type: ApplicationFiled: March 11, 2014Publication date: September 18, 2014Applicant: Analog Devices TechnologyInventors: Santiago Iriarte, Ramon Tortosa Navas, Enrique Company Bosch
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Publication number: 20140266139Abstract: A circuit for generating a temperature-stabilized reference voltage on a semiconductor chip includes a differential amplifier having a first input, a second input and an output. The circuit further includes a CTAT circuit configured to generate a CTAT voltage at an output thereof. A first resistor is coupled between the output of the differential amplifier and the output of the CTAT circuit. Further, the first resistor is connected between the first input and the second input of the differential amplifier.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Inventor: Matthias Eberlein
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Publication number: 20140266138Abstract: A band gap reference circuit is provided that includes a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (Ra), a fifth resistor (Rb), a capacitor (Ca), an operational amplifier A, a first field effect transistor (FET) (P1), a second FET (P2), a third FET (P3), a fourth FET (Pa), a first bipolar junction transistor (BJT) (Q1), a second BJT (Q2), and a third BJT (Q3). P3 and Rb are used to control Pa, which is configured to control current flow to a reference node, and thus a reference voltage (Vref) output by the band gap reference circuit. The band gap reference circuit is configured to output a substantially constant reference voltage and is less sensitive or susceptible to noise from a power supply. Additionally, the band gap reference circuit prevents Vref from overshooting when the band gap circuit is enabled.Type: ApplicationFiled: March 13, 2013Publication date: September 18, 2014Applicant: Taiwan Semiconductor Manufacturing Company LimitedInventor: Taiwan Semiconductor Manufacturing Company Limited
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Patent number: 8836413Abstract: A method for generating a reference voltage includes generating a proportional-to-absolute temperature (PTAT) voltage across a first pseudo resistor. The first pseudo resistor includes a transistor. The method also includes converting the PTAT voltage to a current based on a resistance of the first pseudo resistor. The method also includes mirroring the current using a current mirror circuit and converting the mirrored current to a converted PTAT voltage using a second pseudo resistor. The second pseudo resistor includes a transistor. The first pseudo resistor and the second pseudo resistor include equal transistor types. The method also includes generating a complementary-to-absolute temperature (CTAT) voltage, and summing the converted PTAT voltage and the CTAT voltage to produce the reference voltage. The resulting reference voltage is temperature independent.Type: GrantFiled: September 7, 2012Date of Patent: September 16, 2014Assignee: NXP B.V.Inventors: Andre Gunther, Kevin Mahooti
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Patent number: 8836314Abstract: A reference current source circuit includes a reference voltage generating module, a voltage buffer, an equivalent resistance, a filter capacitor, a current mirror module and a reference current outputting terminal. The voltage buffer includes an operational amplifier and a first FET. The current mirror module includes a second FET and a third FET. The equivalent resistor includes an oscillator, a fourth FET, a fifth FET and a capacitor connected to the fourth FET and the fifth FET. The oscillator is for generating a clock signal whose frequency is related to a charging and discharging capacitor in the oscillator to control charging and discharging of the capacitor in the equivalent resistance. The reference current outputting terminal is for outputting a reference current only related to a capacitance ratio of the capacitor to the charging and discharging capacitor. A reference current source system is further disclosed.Type: GrantFiled: June 13, 2012Date of Patent: September 16, 2014Assignee: IPGoal Microelectronics (Sichuan) Co., Ltd.Inventor: Guojun Zhu
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Publication number: 20140253087Abstract: A fixed voltage generating circuit includes a current mirror, a differential pair, and a resistor coupled to the current mirror. A node of the resistor is coupled to a voltage source. The differential pair includes two resistors coupled to the voltage source for enabling the differential pair to output a fixed voltage.Type: ApplicationFiled: April 18, 2013Publication date: September 11, 2014Applicant: RichWave Technology Corp.Inventor: Chih-Sheng Chen
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Publication number: 20140253073Abstract: A bi-directional voltage positioning circuit includes a voltage to current converter, a current mirror circuit and a switch. The voltage to current converter converts a sensing voltage to a first current, and the sensing voltage is sensed based on a current flowing through an output coil connected between a switching node and an output node. The current mirror circuit mirrors the first current to generate a second current and a third current, the second current is N times greater than the first current, the third current is M times greater than the first current, and N and M are real numbers greater than zero. The switch provides a feedback node with one of the second current and third current in response to a switching control signal, and an output voltage of the output node is divided at the feedback node.Type: ApplicationFiled: February 24, 2014Publication date: September 11, 2014Inventors: Sung-Woo MOON, Myeong-Lyong KO, Yu-Seok KO, Dong-Jin KEUM, Hyun-Wook YOO, Hwa-Yeal YU
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Patent number: 8829883Abstract: In one embodiment, a method includes generating a drive current. Generation of the drive current results in a first leakage current, and the drive current and first leakage current each flow into a first node. The method also includes generating a second leakage current and amplifying the second leakage current to generate a leakage-compensation current. The leakage-compensation current flows away from the first node.Type: GrantFiled: September 9, 2011Date of Patent: September 9, 2014Assignee: Atmel CorporationInventor: Lourans Samid
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Patent number: 8829882Abstract: Current circuits, circuits configured to provide a bias voltage, and methods for providing a bias voltage are described, including a current circuit configured to receive a reference current and having an output at which an output current is provided. One such current circuit includes a first current mirror configured to receive a first portion of the reference current and further configured to mirror the first portion of the reference current to provide a first current. The current circuit further includes a second current mirror configured to receive a second portion of the reference current and receive the first current. The second current mirror is further configured to provide a portion of the first current to the output of the current circuit as the output current and to receive another portion of the first current and mirror the same as the second portion of the reference current.Type: GrantFiled: August 31, 2010Date of Patent: September 9, 2014Assignee: Micron Technology, Inc.Inventor: Aaron Willey
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Publication number: 20140247034Abstract: A circuit and method for a bandgap voltage reference operating at 1 volt or below is disclosed, wherein the operational amplifier (A1) drives resistors (R2, R3) only so that both the flicker noise contribution and the process sensitivity due to the conventional metal oxide semiconductor (MOS) devices used as a current mirror within the proportional-to-absolute-temperature (PTAT) loop are eliminated. Two symmetric resistive divider pairs formed by (R1A/R1B, R2A/R2B) are inserted to scale down both the base-emitter voltages (VEB1, VEB2) of bipolar transistors (Q1, Q2) and the PTAT current (IPTAT) so that an output reference voltage (VREF) becomes scalable. Proper bias currents through transistors (M3, M4), which are used to bias (Q1, Q2) and (R1A/R1B, R2A/R2B) respectively, are produced by an additional V-I converter (319) using VREF itself, resulting in a final process, voltage and temperature (PVT) insensitive output reference voltage.Type: ApplicationFiled: March 4, 2013Publication date: September 4, 2014Applicant: Hong Kong Applied Science and Technology Research Institute Company LimitedInventor: Hong Kong Applied Science and Technology Research Institute Company Limited
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Patent number: 8823444Abstract: A reference voltage generating circuit comprises a pair of variable resistors connected to a pair of bipolar transistors. A differential amplifier amplifies the band gap voltage difference between the bipolar transistors and outputs a reference voltage to an output terminal. An output stage resistor is connected to the output terminal and a resistance dividing circuit. The generating circuit includes temperature compensating circuits that receive tap voltages from resistance dividing circuit and a current proportional to the temperature, then output correction currents. The generating circuit additionally includes a current mirror circuit that outputs a mirror current depending on each correction current. The reference voltage generating circuit thus corrects the temperature dependence of the reference voltage.Type: GrantFiled: March 8, 2013Date of Patent: September 2, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Ryuji Fujime, Masaaki Morikawa
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Publication number: 20140239936Abstract: Reference circuit arrangement according to this invention comprises a branched current path (BE) connecting a first and second terminal (T+, T?) via an intermediate terminal (TN). The intermediate terminal (TN) is connected to a reference terminal (GND). A current path (PTAT) is coupled between the first and second terminal (T+, T?) via the reference terminal (GND). A feedback loop (FB) is connected to the first and second terminal (T+, T?) and designed to control, at the first and second terminal (T+, T?), a virtual ground potential. A reference path (REF) is connected to the feedback loop (FB) having a reference input for receiving from the feedback loop a reference current (Iref) and reference output (Vref) to provide a reference voltage.Type: ApplicationFiled: July 30, 2012Publication date: August 28, 2014Applicant: ams AGInventors: Lorenzo Paglino, Simone Verri
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Patent number: 8819473Abstract: The clock circuit of an integrated circuit operates with variations such as temperature, ground noise, and power noise. Various aspects of an improved clock integrated circuit address one or more of the variations in temperature, ground noise, and power noise.Type: GrantFiled: November 1, 2013Date of Patent: August 26, 2014Assignee: Macronix International Co., Ltd.Inventors: Chung-Kuang Chen, Chun-Hsiung Hung, Han-Sung Chen
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Patent number: 8816665Abstract: A reference voltage stabilization apparatus is disclosed, having an input node for receiving a reference voltage, an output node for coupling with a load, a voltage buffer coupled between the input node and the output node, a charge storage device coupled with the output node, and a charging/discharging circuit coupled with the charge storage device for charging or discharging the charge storage device. The voltage buffer and the charged/discharged charge storage device are coupled with the load so that the voltage at the load equals the reference voltage after a period of time.Type: GrantFiled: February 23, 2012Date of Patent: August 26, 2014Assignee: Realtek Semiconductor Corp.Inventors: Shin-Syong Huang, Jian-Ru Lin
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Publication number: 20140224962Abstract: An example bandgap reference circuit includes an amplifier, a first, a second, and a third switch, and a capacitor. The first switch is coupled between an inverting input and an output of the amplifier to provide a negative feedback loop around the amplifier when the first switch is closed. The capacitor has a first end coupled to the inverting input, and a second end coupled to the second switch, where the capacitor is charged to a voltage substantially equal to an offset voltage of the amplifier when the second switch is closed. The third switch is coupled to a second end of the capacitor, where the voltage across the capacitor is subtracted from an input loop of the reference circuit to cancel the offset voltage of the amplifier when the third switch is closed.Type: ApplicationFiled: February 11, 2013Publication date: August 14, 2014Applicant: OMNIVISION TECHNOLOGIES, INC.Inventor: Per Olaf Pahr
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Patent number: 8797087Abstract: A reference quantity generator for generating a reference quantity includes a reference source configured to provide a reference source signal, a digitally controlled signal source and a digital controller. The digitally controlled signal source is configured to provide a digitally controlled quantity. The reference quantity is determined based on the digitally controlled quantity. The digital controller is configured to provide a digital control signal to control the digitally controlled signal source to adapt the digitally controlled quantity based on the reference source signal using a feedback.Type: GrantFiled: June 24, 2011Date of Patent: August 5, 2014Assignee: Intel Mobile Communications GmbHInventor: Markus Schimper
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Patent number: 8797094Abstract: Embodiments of the invention generally provide generating a ZTC current using resistors that may be integrated into an IC, even if these resistors vary with temperature. Specifically, instead of applying a bandgap voltage across a ZTC resistor, the bandgap voltage may be applied to a temperature-dependent resistor to generate a first current that varies (either proportionally or complementary) with temperature. Additionally, a second current may be generated which compensates for the temperature variance of the first current. If the two currents change in the same manner relative to temperature (i.e., the respective slopes of the currents are the same when the underlying circuit elements are exposed to the same temperature variations), the difference between the currents remains constant. Thus, subtracting the two currents, regardless of the current temperature, results in a ZTC current—i.e., a current that is independent of temperature variations.Type: GrantFiled: March 8, 2013Date of Patent: August 5, 2014Assignee: Synaptics IncorporatedInventors: Clyde Washburn, Eric Scott Bohannon, Brian Mott
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Patent number: 8791684Abstract: A reference voltage generator generates a reference voltage having a stable voltage level insensitive to a temperature variation. A reference voltage generator includes a current generating unit configured to generate a reference current proportional to temperature increase, a voltage adjusting unit configured to adjust a reference voltage corresponding to a current level of the reference current, and a start-up driving unit configured to drive and amplify the reference voltage while the voltage adjusting unit operates.Type: GrantFiled: July 17, 2012Date of Patent: July 29, 2014Assignee: SK Hynix Inc.Inventors: Sang Kug Lym, Yoon Jae Shin
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Patent number: 8791683Abstract: A monolithic voltage reference circuit may include a voltage-mode band-gap reference circuit, a temperature independent differential current source, and a temperature dependent differential current source. The voltage-mode band-gap reference circuit may include an error amplifier having differential input nodes. The temperature independent differential current source may be configured to add in or subtract from the differential input nodes a substantially temperature independent differential current with an allocation between the nodes that is controlled by a selectable output voltage trim setting. The temperature dependent differential current source may be configured to add in or subtract from the differential input nodes a substantially temperature dependent differential current with an allocation between the nodes that is controlled by a selectable temperature drift trim setting.Type: GrantFiled: February 28, 2011Date of Patent: July 29, 2014Assignee: Linear Technology CorporationInventors: Edson Wayne Porter, Iulian Constantin Gradinariu
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Patent number: 8791686Abstract: The voltage reference circuit includes: a first MOS transistor; a second MOS transistor including a gate terminal connected to a gate terminal of the first MOS transistor and having an absolute value of a threshold value and a K value higher than an absolute value of a threshold value and a K value of the first MOS transistor; a current mirror circuit flowing a current based on a difference between the absolute values of the threshold values of the first MOS transistor and the second MOS transistor; a third MOS transistor flowing the current; and a fourth MOS transistor having an absolute value of a threshold value and a K value higher than an absolute value of a threshold value of the third MOS transistor and flowing the current.Type: GrantFiled: September 11, 2012Date of Patent: July 29, 2014Assignee: Seiko Instruments Inc.Inventors: Taro Yamasaki, Fumiyasu Utsunomiya
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Publication number: 20140203794Abstract: A bandgap reference system has a bandgap circuit, an operational transconductance amplifier, and an offset controller. The bandgap circuit includes a pair of diode devices and has a reference terminal at which is provided a bandgap reference voltage. The bandgap circuit provides a differential output having a first output and a second output. The operational transconductance amplifier has a first input coupled to the first output of the bandgap circuit, a second input coupled to the second output of the bandgap reference circuit, and an output coupled to the reference terminal. The offset controller is coupled to the operational transconductance amplifier and to the first and second outputs of the bandgap circuit. The offset controller trims the operational transconductance amplifier as needed to ensure an offset of the operational transconductance amplifier is below a predetermined level.Type: ApplicationFiled: January 24, 2013Publication date: July 24, 2014Inventors: STEFANO PIETRI, Chris C. Dao, Juxiang Ren
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Patent number: 8786355Abstract: Methods and apparatus for a providing temperature-compensated reference voltage are provided. In an example, a temperature-compensated voltage reference circuit includes a current mirror portion and a temperature-compensated output portion coupled to the current mirror portion. The temperature-compensated output portion comprises a very low threshold voltage (Vt) transistor coupled in series with a negative temperature coefficient transistor. The output portion can further include a positive temperature coefficient element coupled in series with the very low Vt transistor. The positive temperature coefficient element can be an adjustable resistive element. The output portion can further include an output transistor having a gate coupled to the current mirror portion and coupled between a supply voltage and the positive temperature coefficient element. The very low Vt transistor can be a substantially zero Vt n-channel metal-oxide-semiconductor (NMOS) transistor, and can be coupled in a diode configuration.Type: GrantFiled: November 10, 2011Date of Patent: July 22, 2014Assignee: QUALCOMM IncorporatedInventors: Wuyang Hao, Jungwon Suh
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Patent number: 8786271Abstract: A circuit for generating reference voltage and reference current includes a band-gap reference circuit and a voltage-to-current converting circuit. The band-gap reference circuit is configured to generate a temperature-independent reference voltage by generating a first current with a positive temperature coefficient. The voltage-to-current converting circuit is coupled to a node of the band-gap reference circuit and configured to convert a voltage with a negative temperature coefficient at the node into a second current with a negative temperature coefficient. The band-gap reference circuit and the voltage-to-current converting circuit share a common current source having a feedback transistor through which a reference current flows. The reference current is divided into the first current of the band-gap reference circuit and the second current of the voltage-to-current converting circuit, thus having a temperature coefficient substantially equal to zero by combining the first current and the second current.Type: GrantFiled: April 19, 2011Date of Patent: July 22, 2014Assignee: Novatek Microelectronics Corp.Inventors: Tsung-Hau Chang, Yung-Chou Lin
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Publication number: 20140197815Abstract: The purpose of the present invention is to provide a circuit that generates a reference voltage with little electrical power consumption, and that has the similar as conventional circuits. A bandgap reference circuit that, to generate an output voltage, adds a voltage proportional to a differential voltage when currents having different current densities are applied to a semiconductor junction, and a voltage proportional to a forward voltage occurring in a semiconductor junction, wherein the bandgap reference circuit is characterized in that the “voltage proportional to the differential voltage” is generated by a first tunneling current element to which the differential voltage is applied, circuits connected to a second tunneling current element or a serial circuit of second tunneling current elements, and a means to apply, to the second tunneling current element, a current proportional to the current applied to the first tunneling current element.Type: ApplicationFiled: May 21, 2012Publication date: July 17, 2014Inventor: Mitsutoshi Sugawara
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Patent number: 8779750Abstract: A reference voltage generating circuit includes: a reference voltage generating circuit element including a first diode characteristic element and a second diode characteristic element, a density of a current flowing through the second diode characteristic element being different from a density of a current flowing through the first diode characteristic element, the reference voltage generating circuit element being configured to output a reference voltage generated based on a difference between voltages respectively applied to the first diode characteristic element and the second diode characteristic element; a first adjusting circuit element configured to adjust a first-order temperature coefficient of the reference voltage; and a second adjusting circuit element configured to adjust a second-order temperature coefficient of the reference voltage.Type: GrantFiled: February 27, 2013Date of Patent: July 15, 2014Assignee: Panasonic CorporationInventors: Masayuki Ozasa, Fumihito Inakai
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Patent number: 8773105Abstract: A voltage regulator includes a master circuit, first and second filters, and a slave circuit. The master circuit provides a second reference voltage based on a first reference voltage and a supply voltage. The first filter provides a filtered second reference voltage based on the second reference voltage. The second filter provides a filtered supply voltage based on the supply voltage. The slave circuit provides a third reference voltage based on the filtered second reference voltage and the filtered supply voltage. The second filter includes an NMOS transistor and a capacitor. The gate and the drain of the NMOS transistor receive the supply voltage. A first terminal of the capacitor is electrically coupled to a source of the NMOS transistor. A second terminal of the capacitor is electrically coupled to ground. The source of the NMOS transistor provides the filtered supply voltage.Type: GrantFiled: January 9, 2012Date of Patent: July 8, 2014Assignee: Marvell International Ltd.Inventors: Chih-Kai Kang, Wyant Chan, Pierte Roo
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Publication number: 20140176113Abstract: A circuit for outputting reference voltage includes: a detecting unit, a feedback unit and an output unit which are respectively connected with an external power source, wherein a plurality of field effect transistors (FETs) are provided in the detecting unit, wherein the detecting unit is for detecting foundry corners of the FETs therein, the feedback unit is for feeding back and comparing a detecting result of the detecting unit, and outputting information after feeding back and comparing, and the output unit is for outputting reference voltage corresponding to the foundry corners of the FETs to an external output terminal. The reference voltage outputted by the circuit for outputting reference voltage of the present invention is capable of varying with foundry corners of the FETs, and achieves compensating for foundry corners of the FETs.Type: ApplicationFiled: October 25, 2013Publication date: June 26, 2014Applicant: IPGoal Microelectronics (Sichuan) Co., Ltd.Inventor: Fangping Fan
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Publication number: 20140176112Abstract: A low voltage bandgap reference circuit includes a positive temperature coefficient circuit unit, a negative temperature coefficient circuit unit and a load unit, wherein the positive temperature coefficient circuit unit comprises a first differential operational amplifier, a first, second and third transistor, a first resistor, a first and second diode, and the negative temperature coefficient circuit unit includes a second differential operational amplifier, a fourth, fifth and sixth transistor, a second resistor and a third diode. The low voltage bandgap reference circuit provides a current having a positive temperature coefficient characteristics and a current having a negative temperature coefficient characteristics to flow through the load unit, whereby generate a stable reference voltage thereon, which the stable reference voltage is less affected by the temperature. Therefore, it avoids the problems of the low voltage bandgap reference circuit can not be activated at low voltage.Type: ApplicationFiled: March 20, 2013Publication date: June 26, 2014Applicant: INTEGRATED CIRCUIT SOLUTION INC.Inventors: CHING-HUNG CHANG, CHUN-LUNG KUO, CHING-TANG WU, CHUNG-CHENG WU, CHUNG-HAO CHEN
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Patent number: 8760220Abstract: A beta enhancement circuit includes a current source connected in series with a transistor between two voltage supply lines. In an embodiment, the voltage supply lines are configured for connection to a power source and ground potential. A resistor device is connected between a control terminal of the transistor device and one of voltage supply lines. A value for the resistor device is selected based on one or more process dependent parameters of the transistor.Type: GrantFiled: June 5, 2013Date of Patent: June 24, 2014Assignee: Marvell International Ltd.Inventors: Hao Zhou, Bingkun Yao, Tao Shui, Yonghua Song
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Publication number: 20140168041Abstract: A reference voltage generator of a gate driving circuit is provided. The reference voltage generator includes a temperature sensing unit, a level clamp unit, a gain adjusting unit and a computing circuit. The temperature sensing unit generates a temperature sensing voltage in response to an environmental temperature. The level clamp unit is coupled to the temperature sensing unit and providing a difference signal in response to the temperature sensing voltage. The gain adjusting unit is used to provide a temperature compensating gain and a first reference level. The gain adjusting unit adjusts the temperature compensating gain and the first reference level according to a control command. The computing circuit is coupled to the level clamp unit and the gain adjusting unit to provide a reference voltage in response to the temperature compensating gain, the first reference level and the difference signal.Type: ApplicationFiled: March 11, 2013Publication date: June 19, 2014Applicant: UPI SEMICONDUCTOR CORP.Inventors: Wei-Jung Chen, Sheng-Chiun Lin