With Amplifier Connected To Or Between Current Paths Patents (Class 323/316)
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Patent number: 7345465Abstract: A DC power supply control apparatus monitors respective terminals supplying positive and negative DC supply voltages to a utility device. The voltage at the negative terminal is compared with a target value for that voltage to produce an offset current representative of any voltage differential therebetween. This offset current is used to produce an offset voltage, that is added to or subtracted from a target value of the positive supply voltage to produce an error amplifier reference voltage. This reference voltage is compared with the voltage at the monitored positive terminal, to produce an error voltage, in response to which the power supply's modulator loop adjusts the power supply's positive output voltage, as necessary, to maintain the intended DC voltage differential between the positive and negative DC supply voltages.Type: GrantFiled: June 12, 2006Date of Patent: March 18, 2008Assignee: Intersil Americas Inc.Inventors: Noel B. Dequina, Robert Haynes Isham
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Publication number: 20080061761Abstract: A temperature sensing circuit includes first, second and third proportional to absolute temperature (PTAT) units, and first and second subtracters. The first PTAT unit generates a first output voltage based on a reference current and a current of N times the reference current, where N is an emitter current density ratio. The second PTAT unit generates a second output voltage based on a current of twice the reference current and a current of 2N times the reference current. The third PTAT unit generates a third output voltage based on the reference current and a current of N times the reference current. The first subtracter performs subtraction on the second output voltage and the third output voltage, and the second subtracter performs subtraction on an output voltage of the first subtracter and the first output voltage.Type: ApplicationFiled: September 6, 2007Publication date: March 13, 2008Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventor: Hyung-seuk Kim
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Patent number: 7342390Abstract: A reference voltage generation circuit has transistors generating a PTAT current that increases in proportion to temperature, a transistor generating a CTAT current that decreases in proportion to temperature, a first variable resistor adjusting an output voltage, a transistor supplying the PTAT current to the first variable resistor via a first switch, a transistor supplying the CTAT current to the first variable resistor via a second switch, and a second variable resistor adjusting the CTAT current. The first switch is on in first and third operation modes and off in a second operation mode. The second switch is on in the first and second operation modes and off in the third operation mode. Switching the operation modes realizes independently outputting a PTAT voltage or a CTAT voltage. Independently adjusting the voltages makes it possible to correct output reference voltage of the reference voltage generation circuit accurately at low cost.Type: GrantFiled: October 30, 2006Date of Patent: March 11, 2008Assignee: Fujitsu LimitedInventors: Suguru Tachibana, Kenta Aruga, Tatsuo Kato
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Patent number: 7342391Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.Type: GrantFiled: June 8, 2007Date of Patent: March 11, 2008Assignee: Renesas Technology Corp.Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
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Patent number: 7332957Abstract: A constant current circuit that generates a constant output current corresponding to an input voltage, comprises a differential amplifying unit to which the input voltage and a feedback voltage to be compared therewith are applied, the differential amplifying unit outputting a differential voltage, a first transistor with a first control electrode to which the differential voltage is applied, a first diode element that is connected to a power-supply side electrode of the first transistor, one or a plurality of second transistors that generates the output current, a feedback voltage conversion block that converts the duplicated current of the diode current flowing through the second transistor into the feedback voltage, and a constant current loading unit that is connected to a ground side electrode of the first transistor, the constant current loading unit making a voltage change in the ground side electrode follow a voltage change in the first control electrode.Type: GrantFiled: August 4, 2006Date of Patent: February 19, 2008Assignee: Sanyo Electric Co., Ltd.Inventor: Kazuo Hasegawa
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Publication number: 20080024106Abstract: A method is provided that includes receiving a detection voltage at a powered device from a powered network, applying the detection voltage to an external resistor to provide a detection signature to the powered network, and applying a reference voltage to the external resistor to generate a reference current after the detection signature has been provided to the powered network.Type: ApplicationFiled: July 25, 2006Publication date: January 31, 2008Applicant: Silicon Laboratories, Inc.Inventors: D. Matthew Landry, Russell J. Apfel
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Patent number: 7323854Abstract: Control loops in a voltage regulator can be stabilized using minimal silicon area. A current limit signal, generated by a current limit control loop in the voltage regulator, can be divided to minimize a zero provided in a compensation set associated with a voltage control loop, thereby stabilizing both loops. The compensation set can include a resistor (the zero) and a capacitor (a pole) connected in series between output and input terminals of an amplifier. Dividing the current limit signal can include injecting a first portion of the current limit signal on a first side of the resistor and injecting a second portion of the current limit signal on a second side of the resistor. The ratio of the first and second portions can be based on a gain of the amplifier, thereby minimizing an effect of the resistor.Type: GrantFiled: August 5, 2005Date of Patent: January 29, 2008Assignee: Micrel, IncorporatedInventor: David W. Ritter
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Patent number: 7323857Abstract: A current source with adjustable temperature coefficient is provided. The current source uses a first current generation unit and a second current generation unit to respectively produce a positive temperature coefficient current and a negative temperature coefficient current. A current addition unit is used to add the positive and negative temperature coefficient currents, and compose the positive and negative temperature coefficient currents according to a predetermined proportion. Finally, a reference current of adjustable temperature coefficient and value is output.Type: GrantFiled: June 14, 2006Date of Patent: January 29, 2008Assignee: Novatek Microelectronics Corp.Inventor: Kuang-Feng Sung
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Patent number: 7321257Abstract: An IC chip has a series regulator built therein. A battery voltage is applied to an input pin. An output of a transistor constituting the series regulator occurs at an output pin via an output pad. A feedback signal derived from an output voltage occurs at an end of a voltage division resistor via a feedback pad. Diodes connect the output pad and the feedback pad.Type: GrantFiled: September 1, 2004Date of Patent: January 22, 2008Assignee: Rohm Co., Ltd.Inventors: Isao Yamamoto, Koichi Miyanaga
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Patent number: 7321245Abstract: A first bias voltage generating circuit which applies a bias voltage to an amplifier circuit of an AD converter has a driving unit and a control unit. The driving unit includes a first bias circuit and a second bias circuit as a plurality of bias circuits which are connected in parallel and have different current driving capabilities. The first bias circuit and the second bias circuit each include a CMOS transistor which is connected directly between a power supply potential and a ground potential, and a switching element which interrupts a feedthrough current. The drains of the CMOS transistors output the bias voltage. The control unit turns on both or either one of the first bias circuit and the second bias circuit, thereby controlling the current driving capability of the entire driving unit.Type: GrantFiled: March 25, 2004Date of Patent: January 22, 2008Assignee: Sanyo Electric Co., Ltd.Inventors: Kuniyuki Tani, Atsushi Wada
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Patent number: 7321255Abstract: A voltage generating circuit outputs a generated voltage corresponding to (a+b+c)-bit digital data from a plurality of generated voltages. The voltage generating circuit includes a first selector of each conductive type and 2a pieces of second selectors of each conductive type. Each first selector is constituted by the conductive type MOS transistor, and based on upper order a-bit of the digital data, outputs one of the generated voltages selected corresponding to low order (b+c)-bit of the digital data. Each second selector is constituted by the conductive type MOS transistor, and based on low order a-bit of the digital data, outputs one of the generated voltages to the first selector of the conductive type. One output and the other outputs of the first selectors of both conductive types are connected to one another.Type: GrantFiled: March 3, 2005Date of Patent: January 22, 2008Assignee: Seiko Epson CorporationInventor: Katsuhiko Maki
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Patent number: 7321225Abstract: A voltage reference generator has been discovered that generates a stable reference voltage that is less than the bandgap voltage of silicon for power supply voltages less than 2V, yet provides sufficient voltage headroom to operate a cascaded current mirror. In one embodiment, the voltage reference generator has a power supply rejection ratio of at least 60 dB and has improved noise performance as compared to traditional bandgap circuits. These advantages are achieved by leveraging the low-beta effect of a CMOS bipolar transistor to generate a current proportional to an absolute temperature.Type: GrantFiled: March 31, 2004Date of Patent: January 22, 2008Assignee: Silicon Laboratories Inc.Inventors: Akhil K. Garlapati, Bruce P. Del Signore, David Pietruszynski
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Patent number: 7319314Abstract: Circuits for regulating a voltage or current to a load(s).Type: GrantFiled: December 21, 2005Date of Patent: January 15, 2008Assignee: Cypress Semiconductor CorporationInventors: Sanjeev Maheshwari, Babak Taheri
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Publication number: 20080007244Abstract: An electronic circuit includes a bandgap reference circuit and a start-up circuit for starting up the bandgap reference circuit. The bandgap reference circuit includes at least one electric path having a semiconductor diode and a resistor connected in series with said semiconductor diode, wherein the voltage across the resistor is proportional to the absolute temperature of the semiconductor diode. The start-up circuit assists starting up the bandgap reference circuit until the voltage across the resistor reaches a preset threshold voltage, and the start-up circuit turns off automatically when the voltage across the resistor has reached the threshold voltage.Type: ApplicationFiled: June 14, 2007Publication date: January 10, 2008Inventor: Dieter Draxelmayr
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Publication number: 20080001592Abstract: A feedback generator of a reference current may include a differential amplifier having a first input for a reference voltage, and a second input for a feedback voltage and generating an output voltage. The feedback generator may also include a first conduction path including a feedback resistor with the feedback voltage applied thereon, and a first transistor controlled by the output voltage and forcing through the feedback resistor the reference current. The feedback generator may also include a second conduction path coupled to the differential amplifier and biasing the differential amplifier based upon the reference current.Type: ApplicationFiled: June 15, 2007Publication date: January 3, 2008Applicant: STMicroelectronics S.r.l.Inventors: Antonino CONTE, Mario Micciche, Vittorio Scavo, Roberto Rosario Grasso
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Patent number: 7312598Abstract: A low drop out (LDO) regulator that includes a novel error amplifier, which is arranged with a first stage that employs both NMOS and PMOS devices that are similarly doped in differential pairs and a second stage that operates with NMOS and PMOS devices in a push-pull arrangement. In addition to the error amplifier, the LDO regulator can also include a startup circuit coupled to an enable voltage, a reference filter circuit coupled to a reference voltage, an output circuit, a quiescent current control circuit, and a pulse generator circuit. Also, an internal RC network is provided to compensate for phase shift. The integrated operation of the components of the regulator enables stable and fast operation of an LDO regulator with no external capacitors connected to the input or output terminals.Type: GrantFiled: August 25, 2006Date of Patent: December 25, 2007Assignee: National Semiconductor CorporationInventor: Shengming Huang
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Patent number: 7309978Abstract: A reference voltage generating circuit with ultra-low power consumption, which includes: a constant current circuit part generating a first constant current from a supply voltage; a current mirror circuit part mirroring the constant current and supplying a second constant current; a voltage control circuit part receiving the second constant current and generating a first reference voltage by using substrate transistors driven by a PTAT (Proportional To Absolute Temperature) voltage and MOS transistors driven by a CTAT (Complementary To Absolute Temperature) voltage; and an output circuit part amplifying an output voltage from the voltage control circuit part to generate second to fourth reference voltages, and feeding back at least one of the second to fourth reference voltages to the voltage control circuit part so that the magnitude of an output voltage is adjusted.Type: GrantFiled: February 23, 2006Date of Patent: December 18, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Ja-nam Ku, Chung-woul Kim, Young-hoon Min, Il-jong Song, Dong-hyun Lee
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Publication number: 20070285076Abstract: A DC power supply control apparatus monitors respective terminals supplying positive and negative DC supply voltages to a utility device. The voltage at the negative terminal is compared with a target value for that voltage to produce an offset current representative of any voltage differential therebetween. This offset current is used to produce an offset voltage, that is added to or subtracted from a target value of the positive supply voltage to produce an error amplifier reference voltage. This reference voltage is compared with the voltage at the monitored positive terminal, to produce an error voltage, in response to which the power supply's modulator loop adjusts the power supply's positive output voltage, as necessary, to maintain the intended DC voltage differential between the positive and negative DC supply voltages.Type: ApplicationFiled: June 12, 2006Publication date: December 13, 2007Applicant: Intersil Americas Inc.Inventors: Noel B. DEQUINA, Robert Haynes Isham
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Patent number: 7304466Abstract: Disclosed is a reference voltage generating circuit comprising a first reference current circuit including first and second current-to-voltage converting circuits, control means for exercising control in such a manner that prescribed output voltages of the first and second current-to-voltage converting circuits become equal, and a first current mirror circuit for supplying currents to respective ones of the first and second current-to-voltage converting circuits; a second reference current circuit having third and fourth current-to-voltage converting circuits, control means for exercising control in such a manner that prescribed output voltages of the third and fourth current-to-voltage converting circuits become equal, and a second current mirror circuit which has a linear input/output characteristic, for supplying currents to respective ones of the third and fourth current-to-voltage converting circuits; and means for outputting a difference current between output current of the first reference current circType: GrantFiled: January 25, 2007Date of Patent: December 4, 2007Assignee: NEC Electronics CorporationInventor: Katsuji Kimura
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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
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Patent number: 7276891Abstract: To augment the temperature dependence of the voltage used to detect temperature in a semiconductor integrated circuit device having a temperature detection function, the operating power supply voltage of the semiconductor integrated circuit device needed to be enhanced. It becomes possible for such a semiconductor integrated circuit device to generate a voltage of great temperature dependence, even under a low operating power supply voltage, by including: a temperature-to-current converter which outputs a first electric current proportional to temperature; a current generator which outputs a second electric current having extremely small temperature dependence; a current subtracter which outputs a third electric current proportional to a differential current obtained by subtracting the second electric current from the first electric current; and a current-to-voltage converter which converts the third electric current into a voltage.Type: GrantFiled: October 25, 2005Date of Patent: October 2, 2007Assignee: Hitachi, Ltd.Inventors: Kazuki Watanabe, Ryo Nemoto, Yoshiaki Yazawa
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Publication number: 20070210784Abstract: A current source with adjustable temperature coefficient is provided. The current source uses a first current generation unit and a second current generation unit to respectively produce a positive temperature coefficient current and a negative temperature coefficient current. A current addition unit is used to add the positive and negative temperature coefficient currents, and compose the positive and negative temperature coefficient currents according to a predetermined proportion. Finally, a reference current of adjustable temperature coefficient and value is output.Type: ApplicationFiled: June 14, 2006Publication date: September 13, 2007Inventor: Kuang-Feng Sung
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Patent number: 7268529Abstract: The present invention provides a band gap type reference voltage generating circuit and a semiconductor integrated circuit having the same, capable of generating a reference voltage of about 1.2V or less whose temperature dependency is low, and realizing reduced offset voltage dependency of a differential amplifier. A band gap part has: a first resistor and a first bipolar transistor connected in series between power supply voltage terminals; a second resistor, a second bipolar transistor, and a third resistor connected in series between the power supply voltage terminals; and a differential amplifier that receives voltages generated by the first and second resistors, and an output of the differential amplifier is applied to the bases of the two transistors.Type: GrantFiled: September 6, 2006Date of Patent: September 11, 2007Assignee: Renesas Technology Corp.Inventors: Toshio Mochizuki, Eiki Imaizumi, Sachiko Okumura
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Patent number: 7265607Abstract: A device comprises an active-pull-up stage and an active-pull-down stage. The device receives at least one reference voltage and provides an regulated output voltage to at least one load. The active-pull-up and active-pull-down stages are adapted to source or sink a current delivered to or received from the at least one load to regulate the output voltage provided to the at least one load. Other embodiments and methods are also claimed and described.Type: GrantFiled: August 31, 2004Date of Patent: September 4, 2007Assignee: Intel CorporationInventors: Saravanan Rajapandian, Peter Hazucha, Tanay Karnik
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Patent number: 7262586Abstract: A shunt type voltage regulator circuit (300) can include a load supply circuit (306) and feedback circuit (308-0) that provide impedance modulated according to a first feedback circuit (308), thus limiting power consumption at higher power supply ranges. In addition, a faster regulation response can be provided by a current conveyor circuit (312?) that can force the voltage at a regulated load node (304) to match that at a replication node (316).Type: GrantFiled: March 31, 2005Date of Patent: August 28, 2007Assignee: Cypress Semiconductor CorporationInventor: Iulian Gradinariu
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Patent number: 7259543Abstract: A bandgap reference circuit is disclosed operating under a predetermined low voltage source. The circuit has a first circuit with a first differential amplifier for generating a first current, a second circuit with a second differential amplifier for generating a second current, and a bandgap reference voltage output module for combining the first current and the second current to output a bandgap reference voltage, wherein the first circuit and the second circuit complement each other for offsetting variations of the bandgap reference voltage due to temperature changes.Type: GrantFiled: October 5, 2005Date of Patent: August 21, 2007Assignee: Taiwan Semiconductor Manufacturing Co.Inventor: Yue-Der Chih
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Patent number: 7259614Abstract: An auto voltage sense circuit uses voltage controlled current sources to generate a desired reference voltage level that closely tracks the variations and changes of a first voltage level and a second voltage level. The auto voltage sensing circuit includes a first voltage controlled current source operable to receive the first voltage level to generate a reference current that is proportional to the first voltage level. The auto voltage sensing circuit also includes a second voltage controlled current source operable to receive the second voltage level and the reference voltage to generate an output current that is proportional to the difference between the second voltage level and the reference voltage. The reference voltage causes the output current to be approximately equal to the reference current so as to generate a reference voltage that is proportional to the difference between the second voltage level and the first voltage level.Type: GrantFiled: July 22, 2005Date of Patent: August 21, 2007Assignee: Integrated Device Technology, Inc.Inventors: William G. Baker, Timothy Gillespie
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Patent number: 7253598Abstract: The performance of a bandgap reference circuit is improved by increasing the ?VBE, and thereby correspondingly decreasing the input sensitivity of the error amplifier in the control loop. The ?VBE can be increased by presenting stacked diode configurations at the amplifier inputs, by increasing the diode ratio presented at the amplifier inputs, and by providing a higher current in the CTAT leg than in the PTAT leg. The stacked diode configuration is achieved by producing isolated diodes with a triple well CMOS process. The stacked diode configuration and the triple well CMOS process also permit the input stage of the amplifier to use N-channel transistors operating in the threshold region.Type: GrantFiled: May 16, 2005Date of Patent: August 7, 2007Assignee: National Semiconductor CorporationInventors: James T. Doyle, Dae Woon Kang, Martin Dermody
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Patent number: 7253597Abstract: A curvature corrected bandgap reference circuit comprises a first bipolar transistor having a base-emitter voltage Vbe1 and operated such that it has a constant operating current, and a second bipolar transistor having a base-emitter voltage Vbe2 and operated such that it has an operating current consisting of an approximately temperature proportional component and a non-linear component. The circuit is arranged such that the ratio of the current densities in the two transistors varies with temperature, such that the difference voltage (?Vbe=Vbe1?Vbe2) includes a residual component which approximately compensates bandgap curvature error.Type: GrantFiled: February 23, 2005Date of Patent: August 7, 2007Assignee: Analog Devices, Inc.Inventor: A. Paul Brokaw
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Patent number: 7253599Abstract: A bandgap reference circuit having a low sensitivity to temperature and supplied voltage installs a compensation circuit on a bandgap reference circuit to substitute a prior art that uses a resistor to match the circuit startup purpose and solve the problem of startup error caused by the manufacturing error. The bandgap reference circuit includes a first amplifier, a second amplifier, and a reference circuit having a plurality of transistors and a plurality of bipolar junction transistors, and the bandgap reference circuit is electrically connected to a same supplied power of which the reference circuit is electrically connected and also includes a plurality of transistors and a compensation circuit of the second amplifier, so as to output a stable startup voltage which has a low sensitivity to the change of temperature and the change of supplied voltage.Type: GrantFiled: June 6, 2006Date of Patent: August 7, 2007Assignee: Nvidia CorporationInventors: An-Chung Chen, Hung-Cheng Huang, Wen-Lung Cheng, Ming-Tse Lin
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Patent number: 7245116Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.Type: GrantFiled: April 7, 2005Date of Patent: July 17, 2007Assignee: Renesas Technology Corp.Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
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Patent number: 7235959Abstract: A low drop-out voltage regulator (300) and method comprising: a differential transistor arrangement (Q1–Q2) for receiving a reference voltage and in dependence thereon producing a regulatred output voltage; an output stage (Q3) for coupling to a load; and a control loop (310) coupled to the differential transistor arrangement for providing a dominant pole. Since a load capacitance is not used for dominant pole, stability of operation may be obtained with a lower load capacitance. The output stage is preferably a closed-loop unity gain amplifier providing a low impedance output. This provides the following advantages: 1—The output capacitor can be dramatically reduced or removed (a low dominant pole, allows the regulator to worth with 0nF output capacitor). 2—internal power consumption can be reduced, improving regulator efficiency. 3—Low output impedance is provided, with very low DC output resistance. 4—The load capacitor can have zero ESR (equivalent serial resistance).Type: GrantFiled: June 16, 2003Date of Patent: June 26, 2007Assignee: Freescale Semiconductor, Inc.Inventor: Thierry Sicard
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Patent number: 7233136Abstract: A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.Type: GrantFiled: December 20, 2005Date of Patent: June 19, 2007Assignee: Denso CorporationInventors: Yasuaki Makino, Norikazu Ohta, Yoshie Ohira, Hirofumi Funabashi
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Patent number: 7230410Abstract: Current source embodiments are provided which generate an output current pulse whose initial and terminal slew rates are enhanced with initial and terminal generators that respectively provide an initial current pulse at initiation of the command signal and a terminal current pulse at termination of the command signal. Current source embodiments also include a correction generator that inserts correction currents to substantially correct Lambda current errors in the current sources.Type: GrantFiled: September 28, 2004Date of Patent: June 12, 2007Assignee: Analog Devices, Inc.Inventor: Edward Perry Jordan
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Patent number: 7224156Abstract: A voltage regulator includes a first stage capable having a first current flowing through it. A second stage has a second current. A third stage is capable of outputting an output voltage and has a third current flowing through it. The first, second and third currents are proportional to each other throughout a range of operation of the voltage regulator between substantially zero output current and maximum output current. The first stage drives the second stage as a low input impedance load.Type: GrantFiled: January 19, 2005Date of Patent: May 29, 2007Assignee: Broadcom CorporationInventor: Chun-Ying Chen
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Patent number: 7215186Abstract: A multi-channel current regulator includes two or more channels, each channel acting as a current source or sink for a respective load. Each channel regulates its load current so that the load current is proportional to an input voltage supplied to the channel. An operational amplifier is shared between the channels. Each channel is selected in a rotating sequence for connection to the amplifier. As each channel is selected, a two-phase refresh cycle is initiated. During the first phase, the output of the amplifier is charged until it substantially matches the drive voltage of the selected channel. This is followed by the second phase where the output of the amplifier is adjusted until the load current of the selected channel is proportional to a set voltage Vset.Type: GrantFiled: April 18, 2005Date of Patent: May 8, 2007Assignee: Advanced Analogic Technologies, Inc.Inventors: Andrew Whyte, Kevin D'Angelo
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Patent number: 7211993Abstract: The invention provides a bandgap voltage reference circuit that is adapted to provide a ?Vbe of sufficiently large value that no amplification is required, and therefore any offset contribution is not gained. Using a stacked arrangement of three pairs of transistors, the invention reduces the requirement for multiple resistors within a circuit and can therefore minimise errors due to resistor matching and value. Internally provided circuitry for reducing voltage curvature is provided with the result that a circuit having low offset sensitivity and curvature correction is provided.Type: GrantFiled: January 13, 2004Date of Patent: May 1, 2007Assignee: Analog Devices, Inc.Inventor: Stefan Marinca
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Patent number: 7205755Abstract: A difference between both emitter voltages of a first transistor having an emitter through which a first current flows, and at least one second transistor having an emitter through which such a second current as to reach a current density thereof smaller than that of the emitter of the first transistor flows, is applied across a first resistor. A second resistor is provided between the emitter of the second transistor and a circuit's ground potential. A third resistor and a fourth resistor are respectively provided between collectors of the first and second transistors and a power supply voltage. Such an output voltage that a collector voltage of the first transistor and a collector voltage of the second transistor become equal is formed in response to the collector voltage of the first transistor and the collector voltage of the second transistor and supplied to bases of the first and second transistors in common.Type: GrantFiled: March 28, 2006Date of Patent: April 17, 2007Assignee: Renesas Technology Corp.Inventors: Takayasu Ito, Mitsuru Hiraki, Masashi Horiguchi, Tadashi Kameyama
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Patent number: 7205827Abstract: A low-dropout regulator comprises a high-gain error amplifier having a differential input stage and a single-ended output, a high-swing high-positive-gain second stage with input connecting to the output of the error amplifier and a single-ended output, a p-type MOS transistor with gate terminal connecting to the output of the second stage, source terminal connecting to the supply voltage, and drain terminal to the output of the low-dropout regulator. A first-order high-pass feedback network connects the output of the low-dropout regulator and the positive input of the error amplifier, and a damping-factor-control means comprising a negative gain stage with a feedback capacitor connects the input and output of this gain stage. A capacitor is connected between the output of the error amplifier and the output of the low-dropout regulator, while a voltage reference connects to the negative input of the error amplifier.Type: GrantFiled: December 19, 2003Date of Patent: April 17, 2007Assignee: The Hong Kong University of Science and TechnologyInventors: Ka Nang Leung, Kwok Tai Mok
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Patent number: 7202654Abstract: A high voltage regulator including a current mirror including a pair of transistors, one of the transistors being connected to a node that outputs an output voltage Vout, a diode stack that includes a plurality of serially connected transistors T0, T1, T2, . . .Type: GrantFiled: September 27, 2005Date of Patent: April 10, 2007Assignee: Saifun Semiconductors LtdInventors: Oleg Dadashev, Alexander Kushnarenko
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Patent number: 7202711Abstract: An integrated driver with improved load current sense capability includes a first transistor, a first amplifier, a second transistor, a third transistor, a second amplifier and a fourth transistor. The integrated driver allows for significantly better fault handling capability, provides accurate thermal and current sensing capability and reduces I/O pin count over prior designs.Type: GrantFiled: September 7, 2005Date of Patent: April 10, 2007Assignee: Delphi Technologies, Inc.Inventors: Mark W. Gose, Douglas B. Osborn
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Patent number: 7202655Abstract: A constant voltage circuit is disclosed that includes a constant voltage generator circuit part converting an input voltage into a predetermined constant voltage in accordance with an externally input control signal and outputting the constant voltage; a first capacitor connected to the output end of the constant voltage generator circuit part; a second capacitor charging the first capacitor; and a switch circuit part controlling charging and discharging of the second capacitor in accordance with the control signal. The switch circuit part charges the second capacitor and blocks the discharging of the second capacitor to the first capacitor when the constant voltage generator circuit part is caused to stop outputting the constant voltage by the control signal, and stops applying the input voltage to the second capacitor and charges the first capacitor when the constant voltage generator circuit part is caused to start outputting the constant voltage by the control signal.Type: GrantFiled: July 25, 2005Date of Patent: April 10, 2007Assignee: Ricoh Company, Ltd.Inventor: Kohzoh Itoh
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Patent number: 7183836Abstract: A fuse sense circuit has a sense amplifier and a post amplifier (gain stage). The sense amplifier has a reference branch and one or more sense (or fuse) branches. The fuse sense circuit determines the state of the fuses using safe currents and provides much higher gain than prior art. The post amplifier is a scaled replica of the reference branch or one of the sense branches in that the devices in the post amplifier maintain the same ratio as similar devices in the reference branch, and components in the post amplifier each matches components in the reference branch. The sense amplifier output is interpreted by the post amplifier's matched gain stage and has a trip point that sufficiently tracks the reference voltage. The result is reduced process and voltage sensitivity, which allows lower differential fuse resistance to be accurately detected with a non-ideal sense amplifier. Multiple gain stages may be added to multiple sense branches for redundancy and single-ended sensing.Type: GrantFiled: May 11, 2005Date of Patent: February 27, 2007Assignee: Intel CorporationInventors: Rachael Jade Parker, Martin S. Denham
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Patent number: 7173407Abstract: A voltage circuit including a first amplifier having first and second inputs and having an output driving a current mirror circuit is provided. Outputs from the current mirror circuit drive first and second transistors which are coupled to the first and second input of the amplifier respectively. The base of the first transistor is coupled to the second input of the amplifier and the collector of the first transistor is coupled to the first input of the amplifier such that the amplifier keeps the base and collector of the first transistor at the same potential. The first and second transistors are adapted to operate at different current densities such that a difference in base emitter voltages between the first and second transistors may be generated across a resistive load coupled to the second transistor, the difference in base emitter voltages being a PTAT voltage.Type: GrantFiled: June 30, 2004Date of Patent: February 6, 2007Assignee: Analog Devices, Inc.Inventor: Stefan Marinca
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Patent number: 7173402Abstract: A low dropout voltage regulator (LDO) includes a regulating circuit, an amplifier, and a first compensating path. The regulating circuit is configured to receive an input signal at an input terminal and provide an output signal at an output terminal in response to a control signal received at the control terminal. The amplifier may have a first input terminal coupled to a first input path and an output terminal be coupled to the control terminal of the regulating circuit via a path to provide the control signal. The first compensating path is coupled between a first node on the first input path and a first node on the path coupling the output terminal of the amplifier to the control terminal of the regulating circuit, the first compensating path including a first compensating capacitor.Type: GrantFiled: February 25, 2004Date of Patent: February 6, 2007Assignee: O2 Micro, Inc.Inventors: Jiwei Chen, Guoxing Li
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Patent number: 7170337Abstract: A low voltage wide ratio current mirror circuit comprises an n times current mirror having an input port for receiving an input current and an m times current mirror coupled in series to the n times current mirror for resulting in an output current of (N*M the input current) being provided to a load where at least one of N and M is other than 1. The circuit provides precision in output current for use with a low voltage power amplifier without incurring an overhead of quiescent current. The low voltage wide ratio current mirror circuit in accordance with a second embodiment of the invention includes a voltage swing reduction circuit in order to provide increased stability thereto. In additional embodiments of the invention, the load is a differential amplification stage for providing differential amplification to differential RF input signals received at first and second RF input ports thereof.Type: GrantFiled: April 20, 2004Date of Patent: January 30, 2007Assignee: SiGe Semiconductor (U.S.), Corp.Inventor: Edward J. W. Whittaker
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Patent number: 7166991Abstract: Circuits and methods to achieve dynamic biasing for the complete loop transfer function of a current mode voltage regulator have been achieved. The circuit comprises a Mirror-Transconductor Amplifier type operational transconductance amplifier (OTA) wherein its transconductance is linearly dependent on its biasing current. This biasing current is a linearly derivative of the OTA's output current. A current amplification circuit couples the regulator output current linearly with said OTA's output current. In this configuration the iterative biasing of the OTA forms a feed-forward loop, which contains a low-pass filter for stability and a negative feedback loop is closed by connecting the regulator voltage output to the OTA input. The invention realizes a purely current mode regulator since all internal currents are generated as a fraction of the output load.Type: GrantFiled: September 23, 2004Date of Patent: January 23, 2007Assignee: Dialog Semiconductor GmbHInventor: Matthias Eberlein
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Patent number: 7164260Abstract: A CMOS bandgap reference (BGR) voltage generator circuit has a passive resistor T-network of low resistance connected between the inverting and non-inverting inputs of the op-amp in the circuit. The op-amp's output is connected to the gates of three PMOS transistors and the drains of two of the transistors are connected in a looped manner to the input terminals of the op-amp. The T-network is placed between these drains that connect to the op-amp. Becuse of the rules governing abstracts, this abstract should not be used to construe the claims.Type: GrantFiled: November 17, 2005Date of Patent: January 16, 2007Assignee: Micron Technology, Inc.Inventor: Philip Neaves
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Patent number: 7161339Abstract: A voltage regulator circuit includes a single high voltage regulator, and a plurality of parallel low voltage regulators capable of receiving an intermediate voltage from the high-voltage regulator, and capable of outputting a regulated output voltage. The intermediate voltage is no higher than a breakdown voltage of the low voltage regulators.Type: GrantFiled: August 20, 2003Date of Patent: January 9, 2007Assignee: Broadcom CorporationInventors: Chun-Ying Chen, Hsiang-bin Lee
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Patent number: 7161412Abstract: A calibration circuit for a current source cell includes a reference current source and a transresistance amplifier forming a feedback loop for calibrating the output current of the current source cell. The reference current source supplies a reference current to a first node switchably connected to the current output node of the current source cell. The transresistance amplifier has an input terminal coupled to the first node and an output terminal switchably connected to a calibration node of the current source cell. With the calibration circuit coupled for calibration, an input current develops at the first node being the difference between the output current of the current source cell and the reference current. The transresistance amplifier receives the input current and generates an output voltage for driving the calibration node. The output voltage has a value operative to nullify the difference between the output current and the reference current.Type: GrantFiled: June 15, 2005Date of Patent: January 9, 2007Assignee: National Semiconductor CorporationInventor: Gabriele Manganaro