With A Specific Feedback Amplifier (e.g., Integrator, Summer) Patents (Class 323/280)
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Patent number: 6975099Abstract: The present application describes a frequency compensation scheme for a linear voltage regulator circuit, or its special case, a low-drop out voltage regulator (LDO). According to one embodiment, the frequency compensation scheme includes two circuits, an inner loop compensation circuit (240), and a circuit (245) at the output in parallel with one of the resistors of the output voltage divider (235). These two compensation elements (240, 245) are not interdependent and may be adjusted separately to provide more optimal frequency compensation. Advantages include smaller compensation circuit elements, die or board area savings, better phase margin over process technology variations and operating conditions, and ease of design adjustment.Type: GrantFiled: February 27, 2004Date of Patent: December 13, 2005Assignee: Texas Instruments IncorporatedInventors: Dolly Y. Wu, David Grant
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Patent number: 6965218Abstract: A voltage regulator includes a two-stage feedback circuit for driving a controller formed by a transistor 10. The feedback circuit includes an error amplifier 30 and an output amplifier 20, a simple compensating circuit in the form of a resistor RSZ inserted between the inverting input 22 and the non-inverting input 24 of the output amplifier 20 resulting in a high phase reserve of the feedback circuit. The resistor RSZ limits the gain of the error amplifier 30 for small load currents by reducing its effective output impedance. This compensating circuit results in the two-stage feedback circuit being highly stable even when very low load currents are involved. This now makes it possible to achieve a very simple linear voltage regulator architecture totally integrated on a single chip. It is especially in battery-powered handhelds such as e.g.Type: GrantFiled: October 6, 2003Date of Patent: November 15, 2005Assignee: Texas Instruments IncorporatedInventors: Kevin Scoones, Martin Rommel
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Patent number: 6954059Abstract: Adjustment of the temperature dependence of the output voltage of a band gap circuit is achieved by intentionally mismatching currents flowing through nodes coupled to the inputs of an amplifier. Each node is coupled to a bipolar junction transistor and a resistor, such that an output voltage of the band gap circuit varies due to the temperature dependence of currents through the bipolar junction transistors and the temperature dependence of currents flowing through the resistors. Networks of parallel metal oxide semiconductor transistors are coupled to each node, with one network including transistors that may be selectively switched into or out of the network to adjust the effective channel width for that network, thereby altering the ratio of effective channel widths and adjusting the temperature dependence of the band gap circuit's output voltage.Type: GrantFiled: April 16, 2003Date of Patent: October 11, 2005Assignee: National Semiconductor CorporationInventor: William MacLean
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Patent number: 6940336Abstract: Voltage regulator with an output transistor MP1, including a first PMOS FET, whereby the input voltage Vdd of the voltage regulator is applied to the source of the output transistor MP1 and where the drain of the output transistor MP1 constitutes the output of the voltage regulator. The voltage regulator, furthermore, includes a regulation circuit 1 that may, for example, consist of an error amplifier and that controls the output transistor in such a way that the least possible deviations between the output voltage Vout and the target output voltage are allowed to occur.Type: GrantFiled: October 28, 2003Date of Patent: September 6, 2005Assignee: Texas Instruments IncorporatedInventor: Peter Bakker
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Patent number: 6936998Abstract: A power glitch free internal voltage generation circuit includes: a voltage divider for dividing level of an internal voltage; a reference voltage generator generating a reference voltage having a predetermined voltage level by dividing a level of an external voltage; a comparator connected to the external voltage and the internal voltage and comparing the divided internal voltage with the reference voltage to generate a compared output; and a driver for supplying the external voltage to the internal voltage in response to the output of the comparator. In this manner, a high voltage level from either of the external voltage and the internal voltage is used as a source of the comparator. This, in turn, stably maintains the internal voltage because the driver for transferring the external voltage to the internal voltage is intercepted in the case where a glitch occurs that lowers the external voltage to a level lower than the internal voltage.Type: GrantFiled: July 16, 2003Date of Patent: August 30, 2005Assignee: Samsung Electronics Co., Ltd.Inventor: Sung-Hee Cho
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Patent number: 6933708Abstract: A voltage regulator having an output terminal adapted to being connected to a load, including an operational amplifier having its non-inverting input connected to a first reference voltage, and its inverting input connected to the output terminal, an inverting stage having its input connected to the output of the operational amplifier, a power switch controlled by the output of the inverter stage, arranged between the output terminal and a supply voltage, and a charge capacitor arranged between the output terminal and a reference supply voltage, including a means for reducing the effective output impedance of the operational amplifier.Type: GrantFiled: December 21, 2001Date of Patent: August 23, 2005Assignee: STMicroelectronics S.A.Inventors: Cécile Hamon, Christophe Bernard, Alexandre Pons
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Patent number: 6933772Abstract: A low drop out voltage regulator (10) that receives an input voltage and generates a substantially constant output voltage includes a gain stage (12), a buffer stage (14), an output driver transistor (16), and first and second load current sense circuits (18, 20). The first load current sense circuit is connected between the output driver transistor and the buffer stage and adaptively increases a bias current of the buffer stage as a function of the load current. The second load current sense circuit is connected between the output driver transistor and the gain stage and adaptively decreases a bias current of the gain stage as the load current increases.Type: GrantFiled: February 2, 2004Date of Patent: August 23, 2005Assignee: Freescale Semiconductor, Inc.Inventors: Jaideep Banerjee, Tushar S Nandurkar
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Patent number: 6928561Abstract: A system and method for providing a power supply dual remote sense. A power supply with a positive remote sense input is coupled to first and second load positions. The load positions are each coupled to a pull-down circuit to provide first and second voltages, respectively, to the inputs of the pull-down circuit. The pull-down circuit output is coupled to the positive remote sense input of the power supply. The voltage level of the pull-down circuit output is no greater than either of the first or second voltages provided at its inputs.Type: GrantFiled: February 14, 2002Date of Patent: August 9, 2005Assignee: Dell USA, L.P.Inventors: Sandor T. Farkas, Quy N. Hoang
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Patent number: 6917189Abstract: The power supply unit is provided with a power supply circuit adapted to generate an output voltage in accord with an instruction voltage, an output condenser Co connected to the output end of the power supply circuit, and an auxiliary output voltage setting circuit adapted to compare the instruction voltage and the output voltage and to cause the output condenser to discharge its electric charge when the instruction voltage becomes lower than the output voltage. Because of the auxiliary output voltage setting circuit, the power supply circuit quickly generates an output voltage in accord with the instruction voltage if the instruction voltage is lowered.Type: GrantFiled: April 25, 2003Date of Patent: July 12, 2005Assignee: Rohm Co., Ltd.Inventors: Ko Takemura, Kiyotaka Umemoto, Kenichi Nakata
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Patent number: 6911806Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control, basing the conversion on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and carries out the pulse width modulation control. Furthermore, the control circuit includes a circuit for discharging charges corresponding to the output voltage of the DC/DC result when a power supply to the control circuit is turned off.Type: GrantFiled: December 15, 2003Date of Patent: June 28, 2005Assignee: Fujitsu LimitedInventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
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Patent number: 6900621Abstract: A digitally controlled hybrid power module is controlled by a programmable controller. The hybrid power module includes a digitally controlled switching supply with an output coupled to an input of a digitally controlled linear voltage regulator. Independent control of switching supply and the linear regulator is provided by the programmable controller, which may be a field programmable gate array (FPGA), microcontroller, or digital signal processor (DSP). The programmable controller may independently control one or more power modules. Each power module may also include enable switching and an associated current clamp for capacitive loads. An output voltage transient suppressor may also be used to control transients, such as those produced under fast switching conditions.Type: GrantFiled: July 3, 2003Date of Patent: May 31, 2005Assignee: InovysInventor: Andre Gunther
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Patent number: 6894469Abstract: The power supply circuit of this invention includes a constant voltage element which generates an output voltage insensitive to change in ambient temperature, a power supply transistor, to a base of which the output voltage of the constant voltage element is applied and from an emitter of which a power supply voltage is provided, a load connected to an emitter of the power supply transistor and a differential amplifier to one input terminal of which an emitter voltage of the power supply transistor is applied and to the other input terminal of which a voltage corresponding to the output voltage of the constant voltage element is applied, and a voltage corresponding to an output voltage of which is applied to the base of the power supply transistor.Type: GrantFiled: March 17, 2003Date of Patent: May 17, 2005Assignee: Sanyo Electric Co., Ltd.Inventors: Kenichi Nakajima, Ikuo Osawa
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Patent number: 6885177Abstract: A switching regulator has an input terminal for receiving an input voltage, an output terminal for outputting an output voltage, a coil connected between the input terminal and the output terminal, and a slope correcting circuit for outputting a signal adapted to carry out slope correction for preventing current oscillation. An error amplifier compares one of the output voltage and a voltage division value of the output voltage with a reference voltage to output a signal, and a switch controls the output voltage with a signal generated using results obtained by arithmetically operating the output signal of the slope correcting circuit and the output signal of the error amplifier. The slope correcting circuit outputs a signal obtained by adjusting the signal adapted to carry out the slope correction in correspondence to the output voltage.Type: GrantFiled: July 24, 2003Date of Patent: April 26, 2005Assignee: Seiko Instruments Inc.Inventor: Atsuo Fukui
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Patent number: 6861832Abstract: The Vt of an MOS transistor is lowered in response to its load current. In a LDO (low dropout) regulator, lowering the Vt of the pass transistor with load increases the level of drive that can be applied to the pass transistor thus allowing a smaller transistor to be used for the same load.Type: GrantFiled: June 2, 2003Date of Patent: March 1, 2005Assignee: Texas Instruments IncorporatedInventor: Raul A. Perez
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Patent number: 6861827Abstract: A method and apparatus to dynamically modify the internal compensation of a low drop-out (LDO) voltage regulator is presented. The process involves creating an additional equivalent series resistance (ESR) from an internal circuit. The additional ESR of the internal circuit is sufficient to ensure the DC output stability. This allows the ESR of the output capacitance to be reduced to zero if desired, for improved transient response.Type: GrantFiled: September 17, 2003Date of Patent: March 1, 2005Assignee: System General Corp.Inventors: Ta-yung Yang, Hsuan-I Pan, Chern-Lin Chen
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Patent number: 6856124Abstract: A method and a circuit to achieve a low drop-out voltage regulator with a wide output load range has been achieved. A fast loop is introduced in the circuit. The circuit is internally compensated and uses a capacitor to ensure that the internal pole is more dominant than the output pole as in standard Miller compensation. The quiescent current is set being proportional to the output load current. No explicit low power drive stage is required. The whole output range is covered by one output drive stage. By that means the total consumption of quiescent or wasted current is reduced. An excellent PSRR is achieved due to load dependent bias current.Type: GrantFiled: July 9, 2002Date of Patent: February 15, 2005Assignee: Dialog Semiconductor GmbHInventors: David Dearn, John Stuart Malcolm, Axel Pannwitz
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Patent number: 6842068Abstract: An multi-stage error amplifier (22) of a power management system (10) is formed to insert a zero to compensate for a high frequency pole that could cause unstable outputs at some output current levels. The error amplifier (22) includes a feed-forward block (40) that isolates the capacitor (36) from other signal paths to facilitate low noise and high efficiency operation.Type: GrantFiled: February 27, 2003Date of Patent: January 11, 2005Assignee: Semiconductor Components Industries, L.L.C.Inventors: Stephane Perrier, Patrick Bernard, Yves Bernard
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Patent number: 6841978Abstract: A voltage regulator has a voltage regulator output (6) for providing a regulated output voltage (Uout) and an internal nonreactive resistor (RZ) arranged in series with an external load (RL) to be connected to the voltage regulator output (6). An internal electrical regulation feedback path of the voltage regulator (10, 11) is tapped both at a first point (A) upstream of the internal nonreactive resistor (RZ) and at a second point (B) downstream of the internal nonreactive resistor (RZ), the second point (B) being located between the internal nonreactive resistor (RZ) and the voltage regulator output (6). For frequencies above a predetermined frequency (fw), the regulation is essentially effective directly via the first point (A) and not via the second point (B), while for frequencies below the predetermined frequency (fw), the regulation is essentially effected via the path first point (A)-internal nonreactive resistor (RZ)-second point (B).Type: GrantFiled: January 27, 2004Date of Patent: January 11, 2005Assignee: Infineon Technologies AGInventor: Bernhard Schaffer
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Patent number: 6812678Abstract: A low drop-out voltage regulator circuit includes: a MOS pass through transistor 12; a resistor feedback circuit 18 and 20 coupled to the MOS pass through transistor 12; an amplifier 16 having an input coupled to the resistor feedback circuit 18 and 20; a Class A output stage 22 coupled between an output of the amplifier 16 and a gate of the MOS pass through transistor 12; and a speedup circuit 48 coupled between the output of the amplifier and the gate of the MOS pass through transistor.Type: GrantFiled: October 10, 2000Date of Patent: November 2, 2004Assignee: Texas Instruments IncorporatedInventor: Paul L. Brohlin
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Patent number: 6806693Abstract: An oscillator circuit is coupled to an enable pin of an Voltage regulator so that total power consumption is minimized in the application. A filter capacitor is coupled to the Voltage regulator such that current is supplied to the load (the application) while the Voltage regulator is disabled. The frequency of the oscillator circuit is low such that power consumption by the oscillator is minimal. The duty cycle (DC) of the oscillator circuit is selected so that the output voltage across the load does not drop below minimum voltage requirements in the application. The total current (I) that is consumed by the system corresponds to: I=DC*Idq+(1−DC)*Iq+Iosc+Iapp, where Iq corresponds to the shutdown current of the LDO, Idq is the ground current of the LDO, Iosc is the oscillator operating current, and Iapp is the average current consumed by the application.Type: GrantFiled: April 14, 2003Date of Patent: October 19, 2004Assignee: National Semiconductor CorporationInventor: Ernest Armand Bron
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Patent number: 6806690Abstract: An LDO regulator automatically switches from the SLEEP mode to the ON mode without the need for an externally generated control signal. The LDO regulator utilizes a pair of drive amplifiers to drive a SLEEP mode pass transistor and a normal ON mode pass transistor, respectively. The regulator also has a circuit for adjusting the bias applied to the amplifiers for each mode of operation.Type: GrantFiled: March 25, 2003Date of Patent: October 19, 2004Assignee: Texas Instruments IncorporatedInventor: Xiaoyu Xi
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Publication number: 20040201369Abstract: A voltage regulator (10) is formed to generate a compensation current to flow when an output voltage of the voltage regulator (10) exceeds a compensation value. The compensation current is at least equal to the leakage current of the output transistor (24).Type: ApplicationFiled: April 14, 2003Publication date: October 14, 2004Applicant: Semiconductor Components Industries, LLC.Inventors: Stephane Perrier, Patrick Bernard, Pierre Daude
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Patent number: 6777920Abstract: The internal power-supply potential generating circuit includes a reference potential generating circuit having small dependency on an external power-supply potential and on a temperature, an MOS transistor for pull up, a level shifter producing a potential lower than a reference potential by a prescribed voltage to a first node and producing a potential lower than an internal power-supply potential by a voltage of the sum of the prescribed potential and an offset potential to a second node, and a differential amplifier bringing an MOS transistor out of conduction in response to the potential of the second node reaching the potential of the first node. Thus, the reference potential may be set lower by the offset voltage, allowing stable reference potential and internal power-supply potential to be obtained even if the external power-supply potential is lowered.Type: GrantFiled: September 20, 2002Date of Patent: August 17, 2004Assignee: Renesas Technology Corp.Inventors: Kiyohiro Furutani, Takeshi Hamamoto, Susumu Tanida
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Patent number: 6765374Abstract: A method an apparatus to dynamically modify the internal compensation of a low drop-out (LDO) linear voltage regulator is presented. The process involves creating an additional equivalent series resistance (ESR) from an internal circuit. The additional ESR of the internal circuit is sufficient to ensure DC output stability. This allows the ESR of the output capacitance to be reduced to zero if desired, for improved transient response. The zero induced by the ESR of the internal circuit is frequency compensated, so that it tracks the position of the output pole as the load varies.Type: GrantFiled: July 10, 2003Date of Patent: July 20, 2004Assignee: System General Corp.Inventors: Ta-yung Yang, Hsuan-I Pan, Chern-Lin Chen, Jenn-yu G. Lin
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Patent number: 6756774Abstract: A constant voltage source includes a constant voltage supplying circuit including an operational amplifier for supplying an output voltage to a load and a feedback circuit for feeding back the output voltage to the operational amplifier; a first inductance unit disposed between the constant voltage supplying circuit and the load; and a first bypass capacitor of which one terminal is coupled between the first inductance unit and the load and the other terminal is coupled to a constant voltage unit.Type: GrantFiled: January 2, 2002Date of Patent: June 29, 2004Assignee: Advantest CorporationInventor: Yoshihiro Hashimoto
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Patent number: 6750638Abstract: A linear regulator includes at least two control loops that monitor different control variables of the output signal. The error signal of the first control loop serves as the reference signal for the second control loop. The conversion of one control variable to the other increases phase margin and improves stability of the frequency response. Also, a capacitor can be coupled to the output of the linear regulator to improve small signal and transient response.Type: GrantFiled: April 17, 2002Date of Patent: June 15, 2004Assignee: National Semiconductor CorporationInventor: Elliot Lawrence Gang
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Publication number: 20040104711Abstract: A voltage regulator includes a two-stage feedback circuit for driving a controller formed by a transistor 10. The feedback circuit includes an error amplifier 30 and an output amplifier 20, a simple compensating circuit in the form of a resistor RSZ inserted between the inverting input 22 and the non-inverting input 24 of the output amplifier 20 resulting in a high phase reserve of the feedback circuit. The resistor RSZ limits the gain of the error amplifier 30 for small load currents by reducing its effective output impedance. This compensating circuit results in the two-stage feedback circuit being highly stable even when very low load currents are involved. This now makes it possible to achieve a very simple linear voltage regulator architecture totally integrated on a single chip. It is especially in battery-powered handhelds such as e.g.Type: ApplicationFiled: October 6, 2003Publication date: June 3, 2004Inventors: Kevin Scoones, Martin Rommel
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Publication number: 20040104712Abstract: Disclosed is a constant voltage power supply, which comprises an error amplifier VEA including a transistor M3, and a transistor M4 having the same ratio between channel width and channel length as that of the transistor M3. The gate and source of the transistor M4 are connected to the gate of a transistor M3 to form a current mirror circuit in conjunction with the transistor M3. Further, the drain of the transistor M4 is connected with a transistor M5 adapted to be switched in response to an external control signal Sg. For example, when the transistor M5 is in ON state, any signal amplification function of the transistor M3 is vanished away, and the gain of the error amplifier VEA is lowered. The circuit configuration for changing the gain of the error amplifier VEA makes it possible to strike a balance between high-speed response characteristic in an active mode and operational stability in a sleep mode, and reduce a circuit area required for being formed on an integrated circuit.Type: ApplicationFiled: November 24, 2003Publication date: June 3, 2004Applicant: Toko, Inc.Inventors: Hiroshi Tanigawa, Satoru Yamane
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Patent number: 6744243Abstract: A low gain feedback compensation circuit is provided on an integrated circuit. The feedback compensation circuit is coupled to a step down power supply on the integrated circuit. The step down power supply is operable to receive an input voltage and to generate an output voltage based on the input voltage. The feedback compensation circuit includes a line regulation circuit. The line regulation circuit is operable to receive the input voltage and a reference voltage. The line regulation circuit is also operable to generate an offset voltage based on the input voltage and the reference voltage.Type: GrantFiled: June 28, 2001Date of Patent: June 1, 2004Assignee: Texas Instruments IncorporatedInventors: David G. Daniels, Dale J. Skelton, Ayesha I. Mayhugh, David A. Grant
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Patent number: 6744242Abstract: In a packaged integrated circuit, the package inductance limits the rate at which off-chip current may be varied in response to a change in on-chip current demand of the integrated circuit. The present invention provides an on-chip voltage regulator circuit for regulating multi-cycle voltage fluctuations of an integrated circuit associated with changes in current demand of the integrated circuit. The voltage regulator sources current to prevent an undervoltage conditions and sinks current to prevent an overvoltage condition.Type: GrantFiled: January 14, 2003Date of Patent: June 1, 2004Assignee: Fujitsu LimitedInventors: Christophe Giacomotto, Robert P. Masleid, Akihiko Harada
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Publication number: 20040095105Abstract: A power supply device relating to the invention comprises a switching element connected between two different potentials, an output smoothing section for smoothing a voltage outputted from a terminal of the switching element and produce an output voltage provided for a load, a driver section for driving and controlling the switching element, and an output current sensing section for monitoring current flowing through the load, the output current sensing section provided in a stage after the output smoothing section. The power supply device is configured in such a way that, when a desired output voltage is produced from an input voltage, the switching element is driven and controlled by the driver section by incorporating a monitored result obtained by the output current sensing section. According to this configuration, it is possible to produce a stable output voltage even if there are abrupt changes of load.Type: ApplicationFiled: November 14, 2003Publication date: May 20, 2004Applicant: ROHM CO., LTD.Inventor: Kenichi Nakata
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Publication number: 20040061485Abstract: A voltage regulator having an output terminal adapted to being connected to a load, including an operational amplifier having its non-inverting input connected to a first reference voltage, and its inverting input connected to the output terminal, an inverting stage having its input connected to the output of the operational amplifier, a power switch controlled by the output of the inverter stage, arranged between the output terminal and a supply voltage, and a charge capacitor arranged between the output terminal and a reference supply voltage, including a means for reducing the effective output impedance of the operational amplifier.Type: ApplicationFiled: June 23, 2003Publication date: April 1, 2004Inventors: Cecile Hamon, Christophe Bernard, Alexandre Pons
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Patent number: 6710584Abstract: In the series regulator, when an external starting voltage source has started operation, a bias current is supplied from a fourth transistor to a reference voltage circuit, and a reference voltage is supplied form the reference voltage circuit to an amplifier. When an output voltage of a power transistor rises, and a value of a divided voltage applied to a sixth transistor has reached a value of a constant voltage being applied to a fifth transistor, the sixth transistor is turned on, and the fifth transistor is turned off. A tenth transistor starts supplying a bias current to the reference voltage circuit. At the same time, a bias switching circuit starts operation, and interrupts a supply of the bias current from the fourth transistor to the reference voltage circuit.Type: GrantFiled: December 21, 2001Date of Patent: March 23, 2004Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuo Kuroiwa, Shinobu Utsunomiya, Tomomi Oda
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Patent number: 6710583Abstract: A low dropout voltage regulator circuit with non-Miller frequency compensation is provided. The circuit includes an input voltage terminal; an output voltage terminal; an error amplifier having a first input coupled to a reference voltage; a voltage follower coupled to an output of the error amplifier; a pass device; and a feedback network. An input terminal of the pass device is coupled to the input voltage terminal. A control terminal of the pass device is coupled to an output of the voltage follower. An output terminal of the pass device is the output voltage terminal. The feedback network includes two resistors in series between the output voltage terminal and ground. A node between the resistors is coupled to a second input of the error amplifier. A frequency compensation capacitor also is coupled between the output voltage terminal and the node.Type: GrantFiled: January 10, 2003Date of Patent: March 23, 2004Assignee: Catalyst Semiconductor, Inc.Inventors: Cornel D. Stanescu, Radu H. Iacob
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Publication number: 20040051508Abstract: A voltage regulator having an output terminal adapted to being connected to a load, including an operational amplifier having its non-inverting input connected to a reference voltage, and its inverting input connected to the output terminal, an inverting amplifier having its input connected to the output of the operational amplifier, a capacitive impedance connected between the input and the output of the inverting amplifier, a power switch controlled by the output of the inverter amplifier, arranged to connect the output terminal to a first supply voltage, said capacitive impedance including a short-circuitable portion associated with active short-circuit means when the current flowing through the load is greater than a predetermined current.Type: ApplicationFiled: June 30, 2003Publication date: March 18, 2004Inventors: Cecile Hamon, Bernard Christophe, Pons Alexandre
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Publication number: 20040046534Abstract: A variable DC/DC converter system is provided that includes a feedback voltage device and a compensation device. The compensation device and compensation components are integrated into a single integrated circuit. The feedback voltage device is integrated into the single integrated circuit. The values of a first resistor and a second resistor determine the output voltage of the DC/DC converter system. The first resistor and second resistor can be external to the integrated circuit and selectable to provide a desired output voltage. Alternatively, the first resistor can be integrated into the integrated circuit, while the second resistor is external to the integrated circuit and selectable to provide a desired output voltage.Type: ApplicationFiled: September 5, 2002Publication date: March 11, 2004Inventors: Alan Michael Johnson, Thomas L. Fowler
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Patent number: 6703815Abstract: A low drop-out regulator is configured to provide high output current with a fast response during transient conditions, while also maintaining low quiescent current under DC conditions. An exemplary low drop-out regulator has an error amplifier, a current feedback amplifier, and a pass device. The low drop-out regulator includes a composite amplifier feedback configuration, with the current feedback amplifier being decoupled from the overall composite feedback configuration and configured to provide effective compensation. As a result, the current feedback amplifier can be configured to operate with low current supplied from the error amplifier and to drive the control terminal of the pass device with sufficiently high current as demanded by a load device. In addition, the current feedback amplifier can be configured to permit the voltage at the control terminal of the pass device to operate from rail-to-rail.Type: GrantFiled: May 20, 2002Date of Patent: March 9, 2004Assignee: Texas Instruments IncorporatedInventor: Hubert J. Biagi
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Patent number: 6703816Abstract: A composite loop compensation circuit and method for a low drop-out regulator configured to facilitate stable operation at very low output load currents is provided. An exemplary low drop-out regulator includes an error amplifier, a pass device, and a composite loop compensation circuit. The compensation loop compensation circuit includes a plurality of segmented sense devices, a plurality of switches and a biasing component. The plurality of segmented sense devices are configured to sense an output load current, i.e., the current from the output terminal of the pass device. The plurality of switches are coupled between the plurality of segmented sense devices and a biasing component. Composite loop compensation circuit is configured to adjust the dominant first pole of the composite feedback loop based on the output load current through biasing of the active resistor component.Type: GrantFiled: July 8, 2002Date of Patent: March 9, 2004Assignee: Texas Instruments IncorporatedInventors: Hubert J. Biagi, Haoran Zhang, Thomas L. Botker
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Patent number: 6700360Abstract: An output stage compensation circuit and method for a low drop-out regulator configured to facilitate stable operation while providing output voltage and current to downstream circuit devices is provided. An exemplary low drop-out regulator is configured with an output stage compensation circuit including one or more segmented sense devices configured to drive one or more fixed current sources. Each segmented sense device is configured to compensate a suitable range of output current and to multiply the effect of associated compensation capacitors. The one or more segmented sense devices are configured to provide pole-zero compensation based on output current. Further, the current range of each segment can be overlapped. As a result, the stability of the low drop-out regulator is not dependent upon the output current requirements or the capacitance requirements of the downstream circuit.Type: GrantFiled: March 25, 2002Date of Patent: March 2, 2004Assignee: Texas Instruments IncorporatedInventors: Hubert J. Biagi, Rodney T. Burt
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Patent number: 6696824Abstract: A variable DC/DC converter system is provided that includes a feedback voltage device and a compensation device. The compensation device and compensation components are integrated into a single integrated circuit. The feedback voltage device is integrated into the single integrated circuit. The values of a first resistor and a second resistor determine the output voltage of the DC/DC converter system. The first resistor and second resistor can be external to the integrated circuit and selectable to provide a desired output voltage. Alternatively, the first resistor can be integrated into the integrated circuit, while the second resistor is external to the integrated circuit and selectable to provide a desired output voltage.Type: GrantFiled: September 5, 2002Date of Patent: February 24, 2004Assignee: Texas Instruments IncorportedInventors: Alan Michael Johnson, Thomas L. Fowler
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Publication number: 20040032240Abstract: A method and circuitry are disclosed that provide for linear operation of a flyback converter through zero output. Broadly, the preferred embodiment enforces a minimum control pulse width thereby isolating energy derived thereby from the eventual load, and dissipating the energy from the minimum control pulse width. The net effect is linear operation inclusive of zero output.Type: ApplicationFiled: May 13, 2003Publication date: February 19, 2004Inventor: Larry Kirn
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Patent number: 6690147Abstract: A low drop out linear voltage regulator (200) overcomes the dynamic quiescent current limitation by creating an internal zero that moves in the same direction and has the same amplitude as that of the output pole without sensing a portion of the load current. The low drop out linear voltage regulator (200) having frequency compensation in accordance with the present invention includes an error amplifier (202), a NMOS pass transistor (204), a variable compensation network (Ci, 206), and a stabilization circuit (208, 210, I3, I4). The error amplifier (202) includes a power supply input connected to a first power supply, a non-inverting input coupled to a reference voltage, a inverting input and an output terminal. The NMOS pass transistor (204) includes a source connected to an output terminal of the voltage regulator, a drain coupled to the second power supply, and a gate coupled to the output terminal of the error amplifier. The variable compensation network (Ci, 206) connects to the error amplifier.Type: GrantFiled: May 23, 2002Date of Patent: February 10, 2004Assignee: Texas Instruments IncorporatedInventor: Olivier Bonto
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Patent number: 6677736Abstract: The invention comprises a voltage regulator including a droop compensation circuit and an energy recovery circuit. The droop compensation circuit adjusts the regulator output voltage to compensate for droop, such as voltage regulator droop, load transistor droop, or other variations to droop that occur in a load circuit over time. The droop compensation circuit compensates for voltage droop by providing an adjusted voltage input to the voltage regulator. The energy recovery circuit permits excess energy at the output of the voltage regulator to be transferred from the voltage output of the regulator to a voltage input of the regulator upon completion of a transmit gate during which the droop compensation circuit is operative. The energy recovery circuit can reduce heat generation and improve power efficiency and reliability.Type: GrantFiled: September 28, 2001Date of Patent: January 13, 2004Assignee: ITT Manufacturing Enterprises, Inc.Inventors: John Arthur Barnes, James John Polston, Makoto Andrew Igawa
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Patent number: 6677737Abstract: A voltage regulator having an output terminal provided for being connected to a load, including an amplifier having its inverting input connected to a reference voltage, and its non-inverting input connected to the output terminal, a charge capacitor arranged between the output terminal and a first supply voltage, first and second voltage-controlled switches each arranged to connect a second supply voltage and the output terminal, and a control means adapted to providing a voltage depending on the output voltage of the amplifier, on the one hand, to the gate of the first switch and, on the other hand, when the current flowing through the first switch reaches a predetermined threshold, to the gate of the second switch.Type: GrantFiled: January 16, 2002Date of Patent: January 13, 2004Assignee: STMicroelectronics S.A.Inventors: Cécile Hamon, Christophe Bernard, Alexandre Pons
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Patent number: 6677735Abstract: The present invention provides a low drop-out voltage regulator (200) that reduces gate capacitance and simplifies the compensation needed to maintain stability, without requiring additional and/or larger Miller capacitors (108), by splitting the output (220, 221) of the driver (112A) for different operational modes, selectively driving a small power device (206), a large power device (214) or both based on the mode.Type: GrantFiled: December 18, 2001Date of Patent: January 13, 2004Assignee: Texas Instruments IncorporatedInventor: Xiaoyu Xi
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Publication number: 20040004468Abstract: A method and a circuit to achieve a low drop-out voltage regulator with a wide output load range has been achieved. A fast loop is introduced in the circuit. The circuit is internally compensated and uses a capacitor to ensure that the internal pole is more dominant than the output pole as in standard Miller compensation. The quiescent current is set being proportional to the output load current. No explicit low power drive stage is required. The whole output range is covered by one output drive stage. By that means the total consumption of quiescent or wasted current is reduced. An excellent PSRR is achieved due to load dependent bias current.Type: ApplicationFiled: July 9, 2002Publication date: January 8, 2004Applicant: Dialog Semiconductor GmbHInventors: David Dearn, John Stuart Malcolm, Axel Pannwitz
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Publication number: 20040000896Abstract: A multimode voltage regulator includes a low current pass device and a high current pass device each adapted for connection between a power supply and a load; an error amplifier responsive to a difference between a reference voltage and a function of the voltage on the load to produce an error signal; and a low power driver responsive in a low load power mode to an error signal for operating the low current pass device to provide low power to the load and a high power driver responsive in a high load power mode to an error signal for operating the high current pass device to provide high power to the load for maintaining efficiency over high and low power load operation.Type: ApplicationFiled: May 12, 2003Publication date: January 1, 2004Inventors: Thomas James Barber, Stacy Ho, Paul Ferguson
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Patent number: 6664772Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control and controlling a direct-current to direct-current conversion based on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and, based on-the amplified output, carries out the pulse width modulation control.Type: GrantFiled: May 21, 2001Date of Patent: December 16, 2003Assignee: Fujitsu LimitedInventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
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Patent number: 6661214Abstract: An embodiment of the present invention comprises a voltage regulator including a droop compensation circuit and a voltage regulator circuit. The droop compensation circuit compensates for an output that changes over a period of time. This variable output may be the result of voltage regulator droop and/or a load transistor droop. For instance, the voltage regulator droop may be associated with the decrease in regulator output voltage that occurs during the course of applying a load. The load transistor droop may correspond to the decrease in RF transistor gain that occurs over the course of a transmit pulse. The variable output could be attributable to other phenomena. Moreover, the variable output that is compensated for is not necessarily decreasing over time, but, in fact, could be increasing over time, or could exhibit increases and decreases over time.Type: GrantFiled: September 28, 2001Date of Patent: December 9, 2003Assignee: ITT Manufacturing Enterprises, Inc.Inventors: Raymond Eugene Hann, James John Polston, Makoto Andrew Igawa
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Patent number: 6661213Abstract: An on-chip, e.g., on a microprocessor, super filter-regulator acts as a voltage regulator and a low-pass filter. The voltage regulator generates a constant DC output voltage and regulates the DC voltage against instantaneous load changes. The low-pass filter and actively filters AC interference out of the DC output voltage. The super filter-regulator provides the filtered and regulated DC voltage to a phase locked loop circuit.Type: GrantFiled: July 27, 2001Date of Patent: December 9, 2003Assignee: Intel CorporationInventors: Eyal Fayneh, Ernest Knoll