Abstract: A ballast (e.g. a fluorescent light ballast) includes a primary ballast for powering the lamp from a power supply (e.g., utility line power) and an battery powered ballast for powering the lamp from a battery when the primary power supply is not energized by the power supply. When power supply power is restored to the ballast, the ballast shuts down the battery powered ballast and a switch circuit operably connects the lamp to the primary ballast. The ballast toggles the switch circuit such that the primary ballast detects replacement of a lamp and resets any fault detection or protection circuits (e.g., an end of lamp life circuit) that may have been triggered during the transition from battery power to power from the power supply.

Abstract: An organic light emitting display device is provided. The device includes a photo sensor adapted to: sense a brightness of ambient light; output a pulse width of an emission control signal corresponding to a sensed brightness of the ambient light; and output a gamma compensation coefficient corresponding to the sensed brightness of the ambient light and a user selected brightness. The device also includes a gamma compensation circuit adapted to adjust a magnitude of a voltage between a plurality of gradation voltages according to the output gamma compensation coefficient. The device also includes a scan driver and a data driver. The device also includes a pixel portion including a pixel adapted to: emit light according to the data signal, the scan signal, and the emission control signal; and display an image corresponding to the user selected brightness.

Abstract: A power supply circuit includes a power supply input for receiving power from a power supply, a power supply output for supplying power to a load, a voltage reference circuit, and a switch circuit. The voltage reference circuit is connected between the power supply input and the power supply output for regulating voltage of the power supply circuit. The switch circuit is connected to the voltage reference circuit and the power supply output. The voltage reference circuit supplies regulated voltage to the switch circuit. The switch circuit controls current between the power supply input and the power supply output to be changed alternately at a certain frequency, thereby changing power output to the load to save electricity.

Abstract: A ballast circuit for controlling preheating, ignition or performing dimming of a gas discharge lamp such as a compact fluorescent lamp is disclosed. The ballast circuit has an inverter connected to a pair of input terminals for receiving a supply voltage, a base drive transformer connected to the switching transistor inverter to provide a drive signal, a resonant circuit connected to the switching transistor inverter, and a loading circuit connected to the base drive transformer. The base drive transformer includes a primary winding and a secondary winding set. The loading circuit is adapted for at least temporarily saturating the base drive transformer and thus effecting in the resonant circuit an oscillating frequency different from a natural resonant frequency of the resonant circuit.

Abstract: In a LED driver using a depletion mode transistor to serve as a current source, the depletion mode transistor is self-biased for providing a driving current to drive at least one LED, thereby requesting no additional control circuit to control the depletion mode transistor. The driving current is independent on the supply voltage coupled to the at least one LED, thereby requesting no additional voltage regulator, reducing the circuit size, and lowering the cost.

Abstract: The invention discloses an LED driving circuit and a controlling method thereof, comprising a power switch and a current sampling unit, as well as a voltage comparison unit for comparing the voltage obtained by the current sampling unit with a first reference voltage; an input voltage sampling unit for converting the sampled input voltage into a current signal; a timing unit for controlling the off-time of the power switch or presetting a fixed off-time; a logical unit for controlling the power switch by means of a power switch driving unit and for controlling the timing switch in the timing unit. The method for controlling the LED driving circuit comprises the step of modulating the off-time of the power switch with the input voltage or the step of presetting a fixed off-time. The invention can be used in LED light cluster driving with the power factor greater than 0.95.

Abstract: A lamp driving circuit, an inverter board and a display apparatus having the inverter board, the lamp driving circuit receiving a direct current voltage and provides the direct current voltage to a square wave generator, and the square wave generator outputting a first square wave voltage having a duty ratio corresponding to a voltage level of the direct current voltage. An inverter controller compares the first square wave voltage with a reference voltage and outputs a second square wave voltage. An inverter provides an output of a lamp driving voltage according to the duty ratio of the second square wave voltage.

Abstract: A circuit device for an LED's driving and stabilizing system includes an AC/DC controllable driving voltage source, a feedback driving controller, an LED demodulation driving controller controllable driving voltage source, an external regulator, and an LED modular device. While various internal conditions or factors of the circuit device may be obtained through integrally or partially setting and computing, the circuit device may also be externally connected to an input signal source according to the characteristics of different attributive conditions to thereby achieve the function of automatic regulation, enabling the LED modular device connected thereto and having been used over a long period of time to have lowered brightness attenuation rate, reduced power loss, reduced heat generation, and accordingly, extended the LED's lifespan.

Abstract: An exemplary backlight control circuit (20) includes: at least two load circuits (210), a pulse width modulation integrated circuit (PWM IC) (250) having a current sampling pin (251), a switching circuit (270), and an input circuit (230). Each load circuit includes a backlight and a backlight inspecting circuit having an output end. The switching circuit includes a first transistor which includes a source electrode connected to ground, a drain electrode connected to the current sampling pin, a gate electrode connected to a power supply. The input circuit includes at least two first diodes, at least two input resistor, a second transistor, and a pink-to-pink detector circuit. The pink-to-pink detector circuit includes a second diode, a second bias resistor, and a second filter capacitor. Each output end of the load circuits is connected to the gate electrode of the second transistor via the input resistor, the first and second diode.

Abstract: A hybrid electric lawnmower is described which includes a first and a second electric motor operating blades and the ability to drive the motors from either 120 VAC line voltage or from a battery pack. There is a user selectable power selection switch for switching between DC or AC power and also a boost and conserve feature which allows for increased speed of the blade as necessary. Running the mower at the conserve setting prolongs battery pack duration per charge. Power supply and control systems allow the user to select operation of the motors in either series or parallel configuration depending on the power source.

Abstract: An adaptable electrical braking system for an electrical propulsion system of a traction vehicle is provided. The electrical braking system is configured to dissipate electrical energy in a plurality of resistor grids. The braking system includes a braking system assembly including a baseline chopper circuit topology. The baseline chopper circuit topology includes a first semiconductor-based circuitry in an enclosure for accommodating the first semiconductor-based circuitry. The braking system further includes a second semiconductor-based circuitry electrically coupled to the first semiconductor-based circuitry to produce a chopper including a chopper circuit topology fully contained in the enclosure. The second semiconductor-based circuitry includes a circuit topology selectable to adapt the baseline chopper circuit topology to meet distinct operational requirements to be fulfilled by the braking system.

Abstract: Under a low load condition, a produced torque is small and a synthetic current command I* with respect to an armature of a servomotor is small so that a magnitude in a negative direction of a reactive current command Id* determined by Id*=?|I*|·sin ? is small. As a result, under the low load condition, the synthetic current flowing through the armature can be small, and generation of wasteful heat can be suppressed. Further, under a high load condition, because a q-axis current Iq that produces the torque is large, voltage saturation is liable to occur. However, at the same time, the overall current command I* is large under the high load condition, and Id* is large in the negative direction. Therefore, a large reactive current Id can be flowed in the negative direction, and voltage saturation under the high load condition can be effectively prevented.

Abstract: A current detecting unit detects three phase current of a three-phase inverter from current flowing between the inverter and a DC power supply. The current detecting unit includes a specified voltage vector generating portion that generates a specified voltage vector indicating a voltage vector that three-phase voltage of the inverter should follow, and a specified voltage vector correcting portion that corrects the generated specified voltage vector. The inverter is controlled in accordance with the specified voltage vector after the correction.

Abstract: There is a method of estimating values of winding currents, at an instant of a period, in a winding of a load, controlled in space vector modulation mode through symmetrical control phases. The winding is cyclically coupled between two supply lines through respective switches. A measuring device is alternately coupled to the supply lines. A current of one supply line, with anticipation smaller than or equal to half of the period with respect to the instant and chosen so the current is equal in amplitude to the winding current, and a current of the supply line with delay equal to the anticipation with respect to the instant, is measured. The winding current is estimated at the instant based upon the supply line currents. A threshold interval is fixed between consecutive switching edges of control phases of the winding and another control phase of the switching period wherein current is measured.

Abstract: Devices and methods for performing dynamic sampling of a back electromotive force (BEMF) measurement are provided. A device has hardware, including a voice coil motor (VCM) for receiving a VCM command signal and a correction circuit, for obtaining the VCM command signal and a coil voltage measurement from the hardware, where the correction circuit removes a transient voltage measurement due to a change in the VCM command signal from the coil voltage measurement and outputs an estimated BEMF measurement.

Abstract: A motor driving circuit drives a motor on receipt of an error signal having a digital value corresponding to a deviation between a current rotation speed of the motor, which is the subject to be driven, and its target value. A digital filter eliminates a high-frequency component of the error signal. A driving unit controls an electric current flowing through the motor in accordance with the digital value of the error signal from which the high-frequency component is eliminated by the digital filter. An upper-limit value setting unit sets an upper limit value to the digital value of the error signal input to the digital filter. The upper-limit value setting unit is configured to be capable of changing the upper limit value in accordance with a setting signal from the outside.

Abstract: An electric motor drive control method includes deriving a target current from a target torque to apply electric current corresponding to the target current to an electric motor. When a rotation speed of the motor is in a predetermined speed region, including a zero rotation speed at which the target current for driving the motor allocated to the target torque is switched discontinuously, the target current corresponding to the rotation speed is obtained through a linear interpolation using the rotation speed and target currents at a traction side and a regeneration side allocated to the target torque such that the electric current corresponding to the target current is applied to the motor.

Abstract: This method for controlling a motorized awning installation comprises: during the deployment of a cloth, a step of supervising the tension of the cloth, and a step of rolling up the cloth on a tube initiated automatically in response to a drop in the supervised tension, and stopped automatically before a perceptible folding of the arms for guidance of the cloth.

Abstract: A stepping motor controlling device according to the present invention includes lead angle computing means which computes a lead angle according to the load torque current deviation of the stepping motor, adding means which adds an angle command to the lead angle to determine a winding exciting angle and voltage applying means which applies a voltage according to the winding exciting angle to the stepping motor.

Abstract: A motor drive system is disclosed that includes a power input configured to receive alternating current (AC) power and a rectifier having a switching frequency selected to convert the AC power to direct current (DC) power. The motor drive unit also includes an input filter circuit connected between the power input and the rectifier and configured to suppress frequency harmonics across a range of harmonics. Additionally, the motor drive unit includes a block filter circuit connected between the power input and the rectifier and configured to substantially block frequency harmonics associated with the switching frequency of the rectifier. Furthermore, the motor drive unit includes an inverter configured to receive the DC power from the rectifier and convert the DC power to a series of pulses configured to drive a motor.

Abstract: In equipment with a built-in fuel cell, there are provided a plurality of secondary cells, and each of the secondary cells has a first state in which an electric power is supplied to a load within the equipment, and a second state in which the electric power that is supplied from the fuel cell is charged, and the first state and the second state is selectively used. The present invention can provide the fuel cell-carried equipment that stably operates due to a power system on which a fuel cell and plural secondary cells are mounted.

Abstract: In a multiple power supply apparatus installed in a vehicle, a first power supply system includes a generator and a first battery. The generator is driven by an operation of the engine. The first battery is chargeable by an electrical output of the generator. A second power supply system includes a second battery. The second battery works to supply electrical power to an electrical load installed in the vehicle. A power transfer module is operative to transfer electrical power supplied from the first power supply system based on at least one of the electrical output of the generator and a charged level of the first battery to the second power supply system. The power transfer module is integrally joined to the first battery to constitute a battery module.

Abstract: A hybrid battery pack and methods of charging and discharging the same make it possible to manage at least two power sources by one circuit. The hybrid battery pack includes a first power source having a first switching circuit, a second power source connected to the first power source in parallel and having a second switching circuit, a current sensor serially connected to the first and second power sources to sense the currents of the first and second power sources, and a controller to obtain the voltages of the first and second power sources so that the first and second power sources are not over-charged or over-discharged and to calculate the entire capacity of the first and second power sources using the amount of currents obtained by the current sensor.

Abstract: A method for operating an external medical device such as a defibrillator includes obtaining a data set from a battery pack and examining the data set to determine whether the battery pack is authenticated for use in the external medical device. If the examination does not confirm the authentication, the method includes causing the device to follow a non-authenticated battery pack protocol. The non-authenticated battery pack protocol may include drawing power from the non-authenticated battery pack only if it is the only available source of power for the external medical device. It may include limiting functionality of the external medical device. It may include modifying the battery status information display for the non-authenticated battery pack.

Abstract: A rechargeable battery system for a portable electronic device is provided. The system includes a battery pack having a first battery and a second battery. The battery pack is preferably configured to electrically connect one of the first and second batteries to the electronic device in a first position, but requires at least partial detachment from the electronic device and reattachment of the battery pack to the electronic device in a second position, different from the first position, to electrically connect the other of the first and second batteries to the electronic device. The system further includes at least one set of charging terminals on the battery pack for charging the first and second batteries.

Abstract: An electrical circuit and method of power management of a cellular telephone includes a battery adapted to produce a battery voltage; a LDO regulator operatively connected to the battery and adapted to provide a constant supply voltage from the battery voltage; and a DC-DC converter operatively connected to the LDO regulator, wherein the DC-DC converter is adapted to step down the constant supply voltage to a lower voltage level, wherein the LDO regulator and the DC-DC converter are embedded on a single integrated circuit chip. The constant supply voltage equals 3.6V at an output of the LDO, and the constant supply voltage is applied to an input of the DC-DC converter. Moreover, the battery voltage equals at most 5.5V.

Abstract: A wireless power transfer system 20 for charging an electronic device 22 having a secondary coil 24 includes a primary controller 38 disposed on a class B surface 30 of a vehicle. A primary coil 52 is electrically connected to the primary controller 38. The primary coil 52 is disposed remotely from the primary controller 38 on a class A surface 28 of the vehicle. A protective shield 66 is disposed on the primary coil 52 to secure the primary coil 52 to the class A surface 28 and indicia 68 indicating an alignment of the secondary coil 24 of the electronic device 22 is disposed on the protective shield 66.

Abstract: A battery management system is disclosed for control of individual cells in a battery string. The battery management system includes a charger, a voltmeter, a selection circuit and a microprocessor. Under control of the microprocessor, the selection circuit connects each cell of the battery string to the charger and voltmeter. Information relating to battery performance is recorded and analyzed. The analysis depends upon the conditions under which the battery is operating. By monitoring the battery performance under different conditions, problems with individual cells can be determined and corrected.

Abstract: A battery pack which includes a battery pack electronic control circuit adapted to control an attached power tool and/or an attached charger. The battery pack includes additional protection circuits, methodologies and devices to protect against fault conditions within the pack, as the pack is operatively attached to and providing power to the power tool, and/or as the pack is operatively attached to and being charged by the charger.

Abstract: An impulse generator including first and second differentiators coupled in parallel to each other, for generating impulses by differentiating a clock signal, and first and second switches for transiting on and off the first and second differentiators respectively to selectively output the impulses generated by the first and second differentiators, and varying polarity of the impulses by changing a direction of a current flowing through load. Accordingly, the negative and positive impulses are selectively output according to the circuit state, reliability of the impulses is improved, and power consumption is reduced.

Abstract: The present invention relates to a state of charge (SOC) compensation method for a vehicle using electrical energy, and a battery management system using the SOC compensation method. To determine the SOC of the battery, charge and discharge current of the battery is used to calculate a first SOC of the battery and a first corresponding voltage, a rheobasic voltage is calculated, an integration error corresponding to a difference between the first voltage and the rheobasic voltage is calculated, a SOC compensation factor is added to the first SOC when the integration error is greater than a first threshold value, and a SOC compensation factor is subtracted from the first SOC when the integration error is less than a second threshold value.

Abstract: A semiconductor device for protecting a rechargeable cell at least from excessive discharge current due to over discharge of the rechargeable cell, includes (a) a first excessive discharge current detection circuit configured to detect first excess of a voltage at an electric current detection terminal exceeding a first voltage level (Vs3), (b) a second excessive discharge current detection circuit configured to detect second excess of the absolute voltage at the electric current detection terminal exceeding a second voltage level (Vs4) higher than the first voltage level, (c) a delay circuit configured to cause each of the first and second excessive discharge current detection circuits to delay output by a predetermined delay time, and (d) a delay reducing circuit configured to produce a delay time reducing signal for reducing the delay time at a predetermined ratio.

Abstract: The electric charge of a capacitor can be reliably discharged. Therefore, an electric discharge controller has an electrically operated machine, an inverter, a capacitor, a voltage command value generating processor for generating a voltage command value for driving, an electric discharge control processor for generating a voltage command value for electric discharge, and a driving signal generating processor. When an electric current is supplied from a direct electric current source to the inverter, the driving signal generating processor generates a driving signal on the basis of the voltage command value for driving. When the supply of the electric current from the direct electric current source to the inverter is interrupted, the driving signal generating processor generates the driving signal on the basis of the voltage command value for electric discharge, and supplies the driving signal to the inverter.

Abstract: Systems and methods for selectively changing the current threshold of current limiting circuitry are provided. The current limit threshold of current limiting circuitry may be selectively changed based on a detected power source using a resistive network. The current limiting threshold may be selected by changing a resistance value of a resistive network electrically coupled to an input on the current limiting circuitry (e.g., battery controller) for programming the current limiting threshold. The resistance value received by the currently limiting circuitry at this input may set the current threshold and thus the maximum magnitude of current that may be provided to charge a battery or other energy storage device located in the electronic device (e.g., a mobile phone).

Abstract: A charging device that may perform charging with larger current is provided. The charging device comprises a switching element for increasing or decreasing charging power, a PWM controlling circuit for intermittently turning the switching element on and off, a current detecting circuit for detecting current flowing through the switching element, and a correcting circuit for correcting output voltage of the current detecting circuit depending on the temperature of the switching element. The PWM controlling circuit has a limiter terminal for turning off the switching element when voltage equal to or above a predetermined value is input, and corrected voltage from the correcting circuit is input to the limiter terminal.

Abstract: DC power for low power loads is provided for vehicles such as snowmobiles where the electrical system includes primarily AC power. DC voltage is provided for gauges and similar loads even though the peak value of the AC is below a desired level. Rectification and regulation of some energy from the alternator is used for supplying the DC power at a desired DC voltage that is above an alternator zero to peak value. A capacitor and a diode are connected in parallel from the alternator with rectifying circuit portions for supplying power to the DC load. A DC voltage monitor senses the DC voltage supplied to the DC load and prevents the DC voltage from rising above the desired voltage by controlling the first rectification, the second rectification, or both.

Abstract: An apparatus for controlling generation of power to be generated by a generator driven by an engine mounted on a vehicle equipped with an electrical load operative on the power from the generator, the generator including a field winding to which current is supplied on the power, and a duty cycle of the current being increased to maintain the power of the generator, the apparatus comprising duty cycle limit means for limiting an increasing rate of the duty cycle in response to an increase in an amount of the load when the engine is in an idle state; rotation frequency detecting means for detecting the rotation frequency of the engine; and limit value deciding means for deciding a limit value for the increasing rate of the duty cycle to a greater value than a limit value corresponding to the idle state, when the rotation frequency detecting means detects a decrease in the rotation frequency.

Abstract: Systems and methods are disclosed for a DC boost converter. The systems and methods combine operation of an inductor with the input capacitor of a DC/AC inverter via a switch configuration to power the DC/AC inverter. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.

Abstract: A digital multilevel memory system includes a charge pump and a voltage regulator for generating regulated high voltages for various memory operations. The charge pump may include a plurality of boost circuits to boost the output of the charge pump during a fast start up. Afterwards, the boost circuits are disabled to allow the charge pump to generate high voltages without boosting. The boost circuits may be successively enabled to boost the voltage. The boost circuits may be loadless. The voltage regulator may operate in an open loop and may include a resistive divider as a reference voltage for regulating the high voltage from the charge pump. The charge pump may include spread spectrum pump clocking to reduce electromagnetic inference for capacitor or inductor on-chip charge pumping.

Abstract: A load control device is adapted to be disposed in series with an AC voltage source and an electrical load and is operable to provide substantially all voltage provided by the AC voltage source to the load. The load control device comprises a controllably conductive device, a controller, a zero-crossing detector, and a power supply for generating a substantially DC voltage for powering the controller. The power supply is operable to charge an energy storage device to a predetermined amount of energy each half-cycle. The controller is operable to determine when the power supply has stopped charging from the zero-crossing detector each half-cycle, and to immediately render the controllably conductive device conductive to conduct the full load current. Before the controllably conductive device begins to conduct each half-cycle, only a minimal voltage develops across the power supply to allow the energy storage device to charge.

Abstract: A low dropout (LDO) voltage regulator includes an output terminal for providing a regulated voltage output to a load, and a plurality of PFETs connected in parallel. Each PFET drains a level of current and the sum of the levels of current are provided as a current output at the output terminal. The LDO voltage regulator also includes a feedback network coupled to the output terminal for providing a voltage feedback signal, and an error amplifier coupled between the plurality of PFETs and the feedback network for sensing a differential voltage. The error amplifier includes an output voltage which is provided to the plurality of PFETs for adjusting the drain of current from each PFET. A summation of the drains of current from each PFET is provided as the current output to regulate the voltage output at the output terminal. Each PFET drains a current level of I0/n and the summation of the drains of current is the current output I0.

Abstract: A voltage regulator having a MOS transistor driver includes a p-channel MOS transistor at a voltage input terminal Vin and a p-channel MOS transistor at a voltage output terminal Vout. A drain of the input side p-channel MOS transistor is connected to the voltage input terminal Vin. A threshold voltage or a voltage lower than the threshold voltage is applied to a gate of the input side p-channel MOS transistor. A drain of the output side p-channel MOS transistor is connected to the voltage output terminal Vout. A current flowing through the input side p-channel MOS transistor drives a voltage regulator circuit and the output side p-channel MOS transistor.

Abstract: A method of providing current mode pulse frequency modulation (PFM) for a switching regulator can include resetting a driver input for a fixed duration when a first current in the driver reaches a first value set by an error amplifier output. The first current can be associated with PMOS switching transistors in the driver. The method can also include setting the driver input signal for the same fixed duration when a second current in the driver reaches a second value. This second current can be associated with NMOS switching transistors in the driver. In one embodiment, the driver can be tristated to ignore both the resetting and the setting. Using this method, perturbations of the inductor current can be substantially corrected and have limited impact on the current waveform beyond the cycle in which they occur.

Abstract: A power supply system includes a first driver circuit to control a corresponding switching of a first switch device and a second switch device in the power supply system via different drive circuits. To reduce losses and thus improve efficiency of the power supply system, a first driver circuit can be configured to initiate a faster rate of transitioning the first switch device between ON and OFF states than a second driver initiates transitioning of the second switch device between ON and OFF states. To reduce the effects of introducing unwanted ripple voltage on an output signal used to drive a dynamic load, a controller in the power supply system can be configured to initiate shedding or adding of multiple voltage converter phases at the same time when load requirements cross a threshold 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 power factor correction circuit including a boost converter, a first capacitor, a first resistor, and a boost control unit is provided. The boost control unit includes a signal generator and a frequency controller. The boost converter transforms a rectified voltage to a correction voltage according to a pulse width modulation (PWM) signal. The first capacitor and the first resistor are coupled between an input terminal and a ground terminal of the boost converter. The boost control unit is adapted to generate the PWM signal, and adjust a duty cycle and a frequency of the PWM signal according to a current flowing through the first resistance, the rectified voltage and the correction voltage. Wherein, the signal generator is adapted to generate a ramp signal and adjust a slope of the ramp signal according to a charging current. The frequency controller adjusts the charging current according to the rectified voltage.

Abstract: The present invention discloses a load-dependent frequency jittering circuit, comprising: a load condition detection circuit for receiving a switching signal and generating an output according to a load condition; a number generator for receiving the output of the load condition detection circuit and generating a number; a digital to analog converter for converting the output of the number generator to an analog signal; and an oscillator for generating a jittered frequency according to the output of the digital to analog converter.

Abstract: Techniques are disclosed to regulate the output power of a power supply. An example technique for regulating a power supply output includes regulating in response to a feedback signal an output current of a power supply in a regulated current region of operation if an output voltage of the power supply is less than a second transition voltage. The output voltage and the output current of the power supply are regulated in a transition region current region of operation in response to the feedback signal if the output voltage of the power supply is between first and second transition voltages or if the output current of the power supply is between first and second transition currents.

Abstract: A power supply controller (25) is configured to accurately adjust the value of an output voltage of a power supply system (10) responsively to the output voltage increasing to an undesirable value. The controller (25) accurately limits an upper value of the output voltage during a light load condition, and rapidly reduces the value of the output voltage during a light load condition, and different control signals to control the switching of the output transistors facilitates rapidly reducing the output voltage.

Abstract: A reference generator circuit generates a reference signal for use by a regulator in generating operational power for circuits and devices. A start-up circuit includes a self-biased voltage reference and a differential amplifier configured to generate a start-up signal to induce current flow in response to the voltage independent reference during the start-up phase of the circuit and cease inducing the current flow following the start-up phase of the circuit. The reference signal is generated by receiving a supply voltage and inducing current flow into a node of a bandgap reference circuit during a start-up phase of the bandgap reference circuit and ceasing inducing the current flow following the start-up phase of the bandgap reference circuit.