Abstract: A circuit and method are provided for interrupting current flow into a voltage regulator from an output thereof when a voltage source (Vpwr) drops below an output voltage (Vout). In one embodiment, the circuit comprises: (i) a comparator supplied by Vout including an output and inputs coupled to Vpwr and Vout; and (ii) transistors coupled to and controlled by the comparator, including a first transistor configured to interrupt a first current path extending between Vout and Vpwr through an output-leg of the regulator when Vpwr drops below Vout. Preferably, the regulator includes a reference-leg and a feedback-circuit coupling Vout thereto, and the first transistor also interrupts a second current path between Vout and Vpwr through the feedback-circuit and reference leg. More preferably, the reference-leg comprises resistors through which it is coupled to ground, and the transistors include a second transistor to interrupt a third current path between Vout and ground.

Abstract: A linear voltage regulator is provided. The linear voltage regulator includes a first circuit configured to receive the first voltage from a voltage source and to remove frequency components of the first voltage in a first frequency range to obtain an output voltage at a primary output node. The linear voltage regulator further includes a second circuit having first and second inverters electrically coupled to the primary output node of the first circuit. The second circuit is configured to receive the output voltage and to remove frequency components of the output voltage in a second frequency range. The second frequency range is greater than the first frequency range.

Abstract: A voltage regulator is disclosed that includes first and second output transistors each outputting a current from the input terminal to the output terminal of the voltage regulator; and a control circuit part controlling the operations of the first and second output transistors to equalize a voltage proportional to an output voltage with a reference voltage. The control circuit part includes first and second error amplifier circuits each amplifying and outputting the difference between the proportional and reference voltages. The second error amplifier circuit consumes a smaller amount of current than the first error amplifier circuit. The control circuit part controls the output voltage by controlling the operations of the first and second output transistors using the first error amplifier circuit or controlling the operation of the second output transistor using the second error amplifier circuit in accordance with a control signal externally input to the control circuit part.

Abstract: A power supply circuit comprises a power transistor, differential amplifier, an I/V converter circuit, and an inverting amplifier, wherein the differential amplifier comprises a first current path in which a first resistor element, a first current mirror transistor, and a first control transistor are connected in series, and a second current path in which a second resistor element, a second current mirror transistor, and a second control transistor are connected in series, and the power supply circuit comprises a phase compensating capacitor element connected in parallel with the inverting amplifier, and a ripple removal rate improving capacitor element which is connected between ground and a connection point between the first resistor element and the first current mirror transistor, or between the ground and a connection point between the second resistor element and the second current mirror transistor.

Abstract: A feedback power control system includes: a multiplying unit receiving a work voltage corresponding to a voltage drop of an electrical component, and a feedback voltage corresponding to a work current flowing through the electrical component, and outputting a measuring voltage corresponding to a consumed power of the electrical component and having a value equal to a product of a value of the work voltage and a value of the feedback voltage; a control unit receiving the measuring voltage from the multiplying unit, and a reference voltage, and outputting a control voltage corresponding to a voltage difference between the measuring voltage and the reference voltage; and a regulating unit providing the feedback voltage to the multiplying unit, and including an amplifier that receives the feedback voltage from a series connection of transistor and a resistor coupled to the electrical component, and the control voltage from the control unit and that controls operation of the transistor.

Abstract: An implantable pulse generator for providing at least one of a voltage and a current stimulation to a tissue of a subject through trough at least two electrodes adapted to be in electrical contact with the tissue of the subject, the implantable pulse generator comprising a stimulation circuit coupled to the at least two electrodes, the stimulation circuit including at least one dual-mode voltage and current source, wherein the stimulation circuit can operate alternatively in a voltage stimulation mode and in a current stimulation mode. The implantable pulse generator also comprises a processing unit coupled to the stimulation circuit, the processing unit being so configured as to control the mode of operation of the stimulation circuit.

Abstract: A system and method are disclosed for providing a pulsating current output having ultra fast rise and fall times. A linear constant current controller is provided that comprises an operational amplifier. A compensation capacitor is connected to an output of the operational amplifier through a switch circuit. The switch circuit closes to initially charge up the compensation capacitor. The switch circuit then opens to isolate the compensation capacitor when the output of the operational amplifier is connected to ground. A value of voltage is maintained on the compensation capacitor so that the compensation capacitor does not need to be recharged for each subsequent cycle of the pulsating current output. The linear constant current controller is capable of generating a pulsating output current that has rise and fall times in the tens of nanoseconds.

Abstract: A constant voltage circuit for converting an input voltage input from an input terminal, converting the input voltage to a predetermined constant voltage, and outputting the converted voltage from an output terminal is disclosed that includes an output transistor for outputting a current corresponding to a control signal from the input terminal to the output terminal, a control circuit part for controlling operation of the output transistor so that a proportional voltage proportional to the voltage output from the output terminal is equal to a reference voltage, and a pseudo-load current control circuit part for supplying a pseudo-load current from the output terminal when detecting that the output transistor is switched off according to a voltage difference between the input voltage and a voltage of a gate of the output transistor.

Abstract: A voltage regulator for providing a voltage regulated output to a load comprises a first loop and a second loop. The first loop comprises a first active device coupled to a first pass device and configured to provide a first, relatively high current output to the load. The second loop comprises a second active device coupled to a second pass device and configured to provide a second, relatively low current output to the load. This provision of two independent loops reduces the quiescent current provided by the voltage regulator under low load conditions.

Abstract: An apparatus and method for suppressing voltage fluctuations across a relay coil is disclosed. The method includes the steps of monitoring a voltage drop across a relay coil by a difference amplifier; providing an output of a reference source and an output of the difference amplifier to an integrator amplifier; providing an output of the integrator amplifier to a transistor; and driving the relay coil by controlling an output of the transistor based on the output of the integrator amplifier, wherein the output of the reference source is selectively applied to the integrator amplifier in response to a monitored undesired voltage fluctuations across the relay coil.

Abstract: A linear regulator is described that includes a mode selection circuit. In one implementation, the mode selection circuit is operable to receive an input voltage and to set an operation mode to one of a first mode or a second mode (e.g., based on a voltage level of the input voltage) so as to generate an output voltage. For example, when the voltage level of the input voltage is within a voltage range, the mode selection circuit can set the first mode as the operation mode to supply the input voltage as the output voltage to a load without voltage regulation. Similarly, when the voltage level of the input voltage is outside the voltage range, the mode selection circuit can set the second mode as the operation mode to regulate the output voltage to the load.

Abstract: A constant-voltage power supply circuit is disclosed that is able to prevent overshoot of an output voltage possibly occurring when changing a constant-voltage circuit in operation and is able to supply a constant output voltage. The constant-voltage power supply circuit includes a first constant-voltage circuit, having a first output transistor and a first output voltage controller, that generates a first reference voltage and generates a first proportional voltage in proportion to a voltage on an output terminal, and a second constant-voltage circuit having a second output transistor and a second output voltage controller that generates a second reference voltage and generates a second proportional voltage in proportion to the voltage on the output terminal.

Abstract: Disclosed are an apparatus and a method for controlling driving of a lamp. The apparatus for controlling driving of a lamp includes a plurality of lamps, a switching module for switching supplied power to output an alternating current (AC) signal, a trans-module for converting the alternating signal into high-voltage signals having different phases to supply the high-voltage signals to the lamps, an open lamp detecting module for adding low-voltage signals having different phases feedback from the trans-module to detect open states of the lamps, and a controller for controlling an operation of the switching module by a signal detected in the open lamp detecting module.

Abstract: Controlling input power is disclosed. In some embodiments, an in situ measurement of an operating condition in an operating environment is compared to a benchmark, and the comparison is used at least in part to determine whether to change input power.

Abstract: A controlling method of a voltage regulator is provided. The voltage regulator at least includes a differential circuit and a pump high-voltage circuit which has a bias path, an output transistor and an output terminal. The controlling method includes steps of: providing at least a pre-charge path to the pump high-voltage circuit, closing the bias path and charging the output terminal with the pre-charge path when the output terminal is transient, detecting an output level of the output terminal, and closing the pre-charge path and open the bias path to bias the output transistor when the output level reaches a predetermined value.

Abstract: Voltage regulator circuitry is provided. The voltage regulator circuitry may contain a drive transistor that is controlled by the output of an operational amplifier. The drive transistor may supply a regulated voltage to a load. The operational amplifier may compare a reference voltage and a feedback signal at its inputs. The operational amplifier may include first and second stages. An adjustable resistor may be provided between the first and second stages. Control circuitry may control the resistance of the adjustable resistor based on the amount of current flowing through the load to ensure stable operation of the voltage regulator circuitry. Overshoot and undershoot detection and compensation circuitry may compensate for overshoot and undershoot in the regulated voltage. Voltage ramp control circuitry may be used to control the ramp rate of the regulated voltage.

Abstract: A step-down circuit generates a second power supply lower than a first power supply. The step-down circuit includes an output terminal connected to a load circuit, an output transistor connected between the first power supply and the output terminal, and having a gate terminal connected to a first node, a monitor transistor connected between the first power supply and a second node, and having a gate terminal connected to the first node, and a feedback circuit which sets a gate voltage of the output transistor in accordance with a difference between a voltage obtained by dividing a voltage of the second node and a reference voltage. A size of the monitor transistor is changed in accordance with an operation mode of the load circuit.

Abstract: Embodiments of the invention may provide for a load regulation tuner that reduces the load regulation effect. The load regulation tuner may include a load current controlled current source that is responsive to a load current from a power transistor of a linear regulator, where the load current controlled current source includes a sensing transistor that generates a fraction of the load current as a sensed partial load current. The load regulation tuner may also include a resistor in parallel with a load current controlled current source, and where the paralleled resistor and the load current controlled current source form at least a portion of a feedback block that adjusts an operation of the linear regulator to provide a substantially constant load voltage.

Abstract: A constant voltage circuit is disclosed that includes an output voltage control transistor outputting a current to an output terminal; a first error amplifier circuit part controlling the operation of the output voltage control transistor; a second error amplifier circuit part causing the output voltage control transistor to increase the output current when there is a rapid decrease in an output voltage from the output terminal; and a current limiting circuit part controlling the operation of the output voltage control transistor so as to prevent the output current therefrom from exceeding a first predetermined value by gradually decreasing the output current and the output voltage alternately when the output current is greater than or equal to the first predetermined value. The current limiting circuit part stops the operation of the second error amplifier circuit part when the output voltage is less than or equal to a second predetermined value.

Abstract: A constant voltage circuit which is capable of quickly responding to a sudden change of an output voltage includes an output transistor, and first and second error amplifiers. The output transistor outputs a power with an output voltage and an output current to a load. The first error amplifier is configured to increase a response speed with respect to changes of the output voltage in accordance with an increase of the output current so as to control operations of the output transistor. The second error amplifier has a response speed faster than the first error amplifier with respect to changes of the output voltage, and is configured to decrease a gain thereof in response to a drain current of the output transistor.

Abstract: In one embodiment, a voltage reference circuit is configured to use two differentially coupled transistors to form a delta Vbe for the voltage reference circuit.

Abstract: A voltage converter comprises a first, a second and a third capacitor (11, 12, 13) which are switched in series in at least one operating state, an input (1) for supplying an input voltage (VIN), an output (2) for providing an output voltage (VOUT), and a compensation circuit (5). The input (1) of the voltage converter is coupled to a capacitor from a group comprising the first, the second and the third capacitor (11, 12, 13). The output (2) of the voltage converter is coupled to a capacitor from the group comprising the first, the second and the third capacitor (11, 12, 13). The compensation circuit (5) is coupled to the first, the second and the third capacitor (11, 12, 13) and adapts a first voltage (V1) of the first capacitor (11), a second voltage (V2) of the second capacitor (12) and a third voltage (V3) of the third capacitor (13) to one another.

Abstract: A regulator for generating, from a first power supply voltage exceeding the breakdown voltage of a low voltage transistor block, a second power supply voltage lower than or equal to the breakdown voltage of the low voltage transistor block, includes an operational amplifier including low voltage transistors and high voltage transistors. An operational amplifier including only low voltage transistors can be employed.

Abstract: A current limited voltage supply including a transistor and a capacitor is provided for powering digital logic cells of an integrated circuit. The transistor is connected in a current mirror configuration, such that a constant reference current is mirrored through the transistor to create a first supply current. The transistor is coupled to the digital logic cells and the capacitor. The first supply current is used to charge the capacitor while the digital logic cells are not switching. While the digital logic cells are switching, the capacitor discharges to the digital logic cells, thereby providing the digital logic cells with sufficient energy to implement high-speed switching. The capacitor minimizes voltage fluctuations within in the current limited voltage supply, such that analog circuitry can be reliably powered from a different branch of the same current mirror circuit.

Abstract: A voltage regulator comprises first and second amplifier stages, a common-source output stage and a feedback path. The output stage drives a capacitive load with a regulated voltage responsive to a signal applied to the output stage. The capacitive load sets the dominant pole of the voltage regulator. The first amplifier stage amplifies the difference between the regulated voltage and a reference voltage. The second amplifier stage drives the output stage with a signal corresponding to the difference between the regulated voltage and the reference voltage. The feedback path couples an output node of the second amplifier stage to an input node of the second amplifier stage for reducing the output resistance of the second amplifier stage to shift a non-dominant pole of the voltage regulator set by the second amplifier stage.

Abstract: A start-up circuit for a high voltage power distribution circuit includes a transistor, a current source which generates ramped current, an operational amplifier which is connected between the current source and the transistor and controls the transistor, a capacitor which is fed the generated ramped current from the current source and is charged by the generated ramped current, the capacitor being connected to the non-inverting input of the operational amplifier, and a feedback capacitor connected from the transistor output to the non-inverting input of the operational amplifier, which is fed the generated ramped current from the capacitor and is discharged. The transistor is fully enabled when the feedback capacitor is fully discharged.

Abstract: A low-dropout (LDO) voltage regulator that includes an error amplifier which compares a reference voltage with a feedback voltage of an output voltage and outputs an error signal based on the result of the comparison, the error amplifier being biased by an input voltage; a first MOS transistor having a gate electrically connected to the error signal, a source electrically connected to the input voltage and a drain electrically connected to the output voltage; a voltage divider which transmits a predetermined part of the output voltage to the error amplifier as feedback voltage; and a level limiter which limits a level of the output voltage from changing beyond and below an offset voltage when a level of a load current changes. In accordance with embodiments, A predetermined number of comparators and MOS transistor type-switches are provided to enhance the slew ratio of the regulated output voltage and to reduce standby electricity consumption.

Abstract: Various voltage regulators and/or voltage regulation systems are disclosed. For example, a voltage regulation system that includes a source follower output is disclosed. The source follower output includes a transistor where the source of the transistor provides a baseline voltage to a regulated voltage output node. The voltage regulation system further includes a body damping circuit and a low speed feedback circuit. The body damping circuit is electrically coupled to the body of the transistor, and is operable to provide a rapid opposition to any voltage disturbance at the regulated voltage output node. The low speed feedback circuit is electrically coupled to the gate of the transistor, and is operable to return the regulated voltage output node to the baseline voltage.

Abstract: A low-dropout linear regulator includes an error amplifier comprising a cascaded arrangement of a differential amplifier and a gain stage having interposed therebetween a frequency compensation network for a loading current to flow therethrough. The regulator includes a current limiter inserted the flow-path of the loading current for the compensation network to increase the slew rate of the output of the differential amplifier by dispensing with the capacitive load in the frequency compensation network during load transients in the regulator.

Abstract: A low-dropout linear regulator includes an error amplifier which includes a cascaded arrangement of a differential amplifier and a gain stage. The gain stage includes a transistor driven by the differential amplifier to produce at a drive signal for an output stage of the regulator. The transistor is interposed over its source-drain line between a first resistive load included in a RC network creating a zero in the open loop gain of the regulator, and a second resistive load to produce a drive signal for the output stage of the regulator. The second resistive load is a non-linear compensation element to render current consumption linearly proportional to the load current to the regulator. The first resistive load is a non-linear element causing the frequency of said zero created by the RC network to decrease as the load current of the regulator decreases.

Abstract: A low drop-out (LDO) voltage regulator with a wide bandwidth power supply rejection ratio (PSRR) is described. In one aspect, the LDO voltage regulator includes two individual voltage regulator circuit stages. A first stage voltage regulator circuit output is at an intermediate voltage (VINT) between an input supply voltage (VDD) and a final regulated output voltage (VREG). A second stage voltage regulator circuit output is at the final regulated output voltage (VREG) and is optimized for noise-sensitive analog circuits across a wide operating bandwidth. The first stage voltage regulator circuit has a zero frequency while the second stage voltage regulator circuit has a matching pole frequency to minimize the AC response from VDD to VREG across all frequencies.

Abstract: Voltage regulator circuitry is provided. The voltage regulator circuitry may contain a drive transistor that is controlled by the output of an operational amplifier. The drive transistor may supply a regulated voltage to a load. The operational amplifier may compare a reference voltage and a feedback signal at its inputs. The operational amplifier may include first and second stages. An adjustable resistor may be provided between the first and second stages. Control circuitry may control the resistance of the adjustable resistor based on the amount of current flowing through the load to ensure stable operation of the voltage regulator circuitry. Overshoot and undershoot detection and compensation circuitry may compensate for overshoot and undershoot in the regulated voltage. Voltage ramp control circuitry may be used to control the ramp rate of the regulated voltage.

Abstract: In one embodiment, a method for soft-start in a power converter includes the following: providing a feedback signal indicative of the output voltage of the power system at a first input terminal of an error amplifier in a negative feedback loop of the power converter; providing a reference voltage at a second input terminal of the error amplifier; comparing the feedback signal against the reference voltage to generate a control signal for regulating an output voltage of the power converter; charging a soft-start capacitor coupled to the second input terminal of the error amplifier with a current for establishing the reference voltage; and adjusting the current in response to the control signal so that the error amplifier is prevented from saturation.

Abstract: A voltage error correction system includes a voltage converter, a first and a second analog to digital converters, a subtracter, an adder, and a digital voltage generator. The voltage converter adjusts an input voltage proportionally, adds the adjusted input voltage to a reference voltage to obtain a positive voltage, and outputs the positive voltage. The first analog to digital converter converts the positive voltage into a first digital voltage, the second analog to digital converter converts the reference voltage into a second digital voltage, the subtracter subtracts the second digital voltage from the first digital voltage and outputs a difference voltage, and the adder outputs a corrected voltage by adding the difference voltage of the subtracter to a compensation voltage.

Abstract: An electronic device has an LDO regulator for varying loads. The LDO regulator includes a primary supply node coupled to a primary voltage supply. An output node provides a secondary supply voltage and a load current. A bias current source generates a bias current. A gain stage coupled to the bias current source increases the maximum available load current. The gain stage includes a first MOS transistor biased in weak inversion coupled to a current mirror which mirrors the drain current through the first MOS transistor to the output node. The gate-source voltage of the first MOS transistor increases in response to a decreasing secondary supply voltage level at the output node to increase the available load current.

Abstract: A power element bypass and voltage regulation circuit shutdown is used in a low drop out (LDO) bypass voltage regulator to minimize current drawn by the voltage regulator circuit when the supply input voltage approaches the regulated output voltage of the voltage regulation circuit. Two modes of operation are used in the low drop out (LDO) bypass voltage regulator. A regulate mode is used when the supply input voltage is greater than the reference voltage input, and a track mode is used when the supply input voltage is less than or equal to approximately the regulated output voltage of the voltage regulation circuit. Hysteresis may be introduced when switching between the regulate and track modes of operation.

Abstract: A system drives one or plurality of LEDs regulating their brightness by controlling LEDs average current or voltage. The system includes a switching power converter and an integrated digital regulator with at least one of electrical, thermal and optical feedbacks. The regulator is constructed as a hysteretic peak current mode controller for continuous mode of operation of the power converter. For discontinuous mode of operation of the power converter a pulse averaging sliding mode control is being used. Average LED current is measured by integrating LED pulse current at off time and hysteretically adjusting on time of the power switch. Input battery is protected from discharging at abnormally low impedance of the output.

Abstract: The present invention discloses an LDO (Low DropOut) linear voltage regulator, which is based on an NMC (Nested Miller Compensation) architecture and can be capacitor-free, wherein an active resistor is added to the feedback path of the Miller compensation capacitor to increase the controllability of the damping factor, solve the problem of extensively using the output capacitor with a parasitic resistance, and solve the problem that a compromise must be made between the damping factor control and the system loop gain. Further, the present invention utilizes a capacitor-sharing technique to reduce the Miller capacitance required by the entire system and accelerate the stabilization of output voltage without influencing stability.

Abstract: A power circuit and a charge pumping circuit add one control switch of small size to control a power transistor, and save one switch of large area and one capacitor of large area as compared with a conventional power circuit and a conventional charge pumping circuit. The power circuit includes a power processing circuit, a linear voltage-regulating switch, and a capacitor. The linear voltage-regulating switch includes a power transistor and a control switch. The control switch has a first end coupled to a gate of the power transistor and a second end coupled to one of a drain and a source of the power transistor. When the control switch is “on”, the power transistor is “off”. When the control switch is “off”, the voltage on the drain of the power transistor is maintained at a predetermined value by the linear voltage-regulating switch.

Abstract: A linear regulator for outputting a regulated voltage with improved rejection of high frequency components in the power supply. The linear regulator includes an op-amp connected in a linear feedback loop to drive first and second current legs based on a voltage reference. An output driver includes a load capacitance across which the regulated voltage is output, and further includes a ratio-driven current mirror having a mirror ratio defined by relative sizes of active devices in the first and second current legs, as compared with relative sizes of active devices in the output driver. Because the output driver and its load capacitance are provided outside the linear feedback loop, large values for the load capacitance can be selected without destabilization of the feedback loop. Thus, the value of the load capacitance can be chosen at any value according to frequency rejection requirements.

Abstract: A current-restriction circuit includes an input terminal to which an input voltage is input, an output terminal from which an output voltage is output, a driver transistor connected to the input terminal as well as the output terminal, a sense transistor connected to the output terminal as well as the input terminal via a sense resistor, a first operational amplifier circuit, and a bias-voltage change circuit. Control terminals of the driver transistor and the sense transistor are connected together and connected to an output terminal of the first operational amplifier circuit. The first operational amplifier circuit receives both a bias voltage with reference to an electrical potential at the input terminal and a decrease in a voltage at the sense resistor. The bias-voltage change circuit keeps the bias voltage below a predetermined bias voltage according to a voltage difference between the input voltage and the output voltage.

Abstract: A soft-start voltage circuit includes an operational amplifier, a first and a second capacitors, a first and a second switches, and a voltage level shifter. The operational amplifier includes a positive end, a negative end, and an output end coupled to the negative end of the operational amplifier for outputting the soft-start voltage. The voltage level shifter is coupled between the first capacitor and the positive end of the operational amplifier for shifting a level of the voltage on the first capacitor. The first switch is coupled between the first and the second capacitors for coupling the first and the second capacitors according to the clock. The second switch is coupled between the second capacitor and the negative end of the operational amplifier for coupling the second capacitor and the negative end of the operational amplifier according to the inverted clock.

Abstract: A low drop out (LDO) voltage regulator (10) includes a pass transistor (MPpass) having a source coupled by an output conductor (4) to a load and a drain coupled to an input voltage to be regulated. An error amplifier (2) has a first input coupled to a reference voltage, a second input connected to a feedback conductor (4A), and an output coupled to a gate of the pass transistor. A parallel path transistor (MPpa) has a source coupled to the input voltage, a gate coupled to the output (3) of the error amplifier (2), and a drain coupled to the feedback conductor. A feedback resistor (Rf) is coupled between the feedback conductor and the output conductor.

Abstract: A driving circuit that improves the loading transient performance of a power converter is provided. The driving circuit comprises an input unit, an output unit, a reference current generating unit, and a discharging unit. The input unit receives a first voltage signal and a second voltage signal. The first voltage signal has a first voltage V1 and the second voltage signal has a second voltage V2. The output unit outputs a third voltage signal. The input unit, the output unit, and the reference current generating unit form an error amplifier. A discharging unit has a discharging current path. When V1 is larger than (1+a)*V2, the discharging current path is turned ON. When V1 is smaller than (1+b)*V2, the discharging current path is turned OFF.

Abstract: A method includes receiving an activation signal at a semiconductor device and generating an output power signal at the semiconductor device in response to receiving the activation signal. The output power signal has a duty cycle. The method also includes providing the output power signal to a load. The output power signal provides power to the load. An amount of power provided to the load is based on the duty cycle of the output power signal. In addition, the method includes adjusting the duty cycle of the output power signal using at least one of a current limiter and a power limiter integrated in the semiconductor device.

Abstract: Voltage regulators are provided. In one embodiment of the voltage regulators, a differential amplifier receives a reference voltage and a feedback voltage, to generate a control signal according to a voltage difference between the feedback voltage and the reference voltage. An output transistor has a first terminal coupled to a power voltage, a control terminal coupled to the differential amplifier for receiving the control signal, and a second terminal coupled to an output terminal. A voltage feedback circuit is coupled between the output terminal and a ground voltage to generate the feedback voltage. A discharge transistor has a first terminal coupled to the ground voltage, a control terminal coupled to a first control signal, and a second terminal coupled to the output terminal through a first resistor in the voltage feedback circuit.

Abstract: A circuit for providing an improved “feed forward” zero in a feedback loop such that the zero has a frequency dependent on the transconductance (gm) of a common gate transistor, and pole and zero separation that is dependent on a multiple of the gm. The circuit includes an error amplifier and a compensation circuit. The compensation circuit provides a first feedback current and a second feedback current. The error amplifier receives a reference signal and a feedback signal. The feedback signal is provided by summing the first feedback current and the second feedback current.

Abstract: A voltage generator is used for generating a voltage reference with high power supply rejection. One embodiment of the circuit includes a voltage regulator and a bandgap voltage circuit and an amplifier. The voltage regulator including an input node is coupled to an external power supply for generating a regulated voltage source. A bandgap voltage circuit includes a first and a second resistor and a first and a second transistor to generate a voltage difference between the base-to-emitter voltages of the first and the second transistors. The second resistor is coupled to the first resistor and the first transistor for generating the first predetermined voltage in response to the voltage difference. An amplifier circuit is coupled to the first transistor of the bandgap voltage circuit for receiving a first amplifying signal and generating an amplified signal so as to regulate the regulated voltage source.

Abstract: A low-dropout voltage (LDO) regulator that creates a zero in the open loop gain using a relatively small-sized current control element to divert part of the supplied load current through a “zero” resistor before adding it to the output load. The main part of the output load is passed through a relatively large second current control element. A control signal generated by an error amplifier (e.g., an op-amp) is used to control the small current control element, but is passed through a boost zero compensating resistor before being applied to the large current control element. The voltage signal developed across the “zero” resistor mimics the magnitude and phase of a zero in the loop. This voltage signal is added to the loop gain by, for instance, using a bypass capacitor, and the resulting feedback signal is supplied to the error amplifier.

Abstract: A system including a first transistor, a first capacitor and a circuit. The first transistor has a first control input and is configured to regulate an output voltage. The first capacitor is coupled at one end to the first control input and at another end to a circuit reference. The circuit is configured to provide a first voltage to the first control input, where the first voltage includes an offset voltage that is referenced to the output voltage and adjusted to compensate for variations in the first transistor.