Abstract: A bypass low dropout regulator has a pass gate coupled to a voltage rail. The pass gate receives a pass gate control signal on a pass gate control line and controllably drops a voltage from a rail to a regulated output in accordance with the pass gate control signal. A differential amplifier generates the pass gate control voltage using a reference and feedback from the regulated output. A bypass switch selectively bypasses the regulator control signal, in response to a bypass signal, by placing a pass gate ON voltage on the pass gate control line. Optionally, and ON-OFF mode circuit selectively disables the pass gate in response to a system ON-OFF signal.

Abstract: A embodiment relates to a current estimation circuitry for a converter comprising: an integrator for integrating a voltage across an inductor of the converter; a current sense unit for obtaining a signal that is associated with the current flowing through at least one of the electronic switches of the converter; and a control unit for adjusting at least two parameters of the integrator based on comparing the output of the integrator with the signal provided by the current sense unit.

Abstract: A controller for a switch mode regulator with discontinuous conduction mode (DCM) correction which includes a correction network and a modulator. The correction network detects a low load condition indicative of regulation error during DCM and asserts an adjust value indicative thereof. The modulator receives the adjust value and adjusts operation accordingly to improve regulation during DCM. The correction network receives or determines a regulation metric, such as periods between successive pulses of a pulse control signal, or a current sense signal indicative of load current, and compares the regulation metric with one or more thresholds for determining the level of adjustment. Adjustment may be made using one or more methods, such as adjusting pulse on-time, adjusting pulse off-time, adjusting frequency of operation, etc.

Abstract: A current resonance power supply includes a current detecting unit detecting a current flowing through a primary side of a transformer and a current compensating unit compensating the current detected by the current detecting unit in accordance with a variation in voltage input into the primary side of the transformer. The current resonance power supply detects overcurrent on the basis of an output from the current compensating unit.

Abstract: Embodiments of systems, methods and apparatuses of a switching voltage regulator are disclosed. One switching voltage regulator includes a series switch element, a shunt switch element, a PWM controller, and a mode controller. The PWM controller includes an error amplifier and a switching controller. The error amplifier generates an error signal based on a difference between a reference voltage and an output voltage. Further, the switching controller is operative to generate switch element control voltages based on the error signal, for controlling opening and closing of the series switch element and the shunt switch element, wherein the opening and closing of the series switch element and the shunt switch element generates a switching voltage. The mode controller is operative adjust a gain of the error amplifier over a selected range of frequencies based on a parameter indicative of a likelihood of oscillations in the output voltage.

Abstract: A regulating circuit includes a first comparator configured to control a turning on and a turning off of a first transistor based on a first comparison a reference voltage to a feedback voltage. The first transistor is coupled between an output node and a first voltage supply. A second comparator is configured to control a turning on and a turning off of a second transistor based on a second comparison of the reference voltage to the feedback voltage. The second transistor is coupled to the output node. A high-impedance circuit is coupled in series with the second transistor such that the high-impedance block is disposed between the second transistor and a second power supply. The high-impedance circuit is configured to generate a constant current between the output node and the second voltage supply when the second transistor is turned on.

Abstract: The invention relates to a method for managing an electrical network. The electrical network includes two power centers making it possible for each one to supply several loads, each power center including: an electrical power supply bus, a plurality of reversible converters making it possible to exchange energy between the bus and the various loads , routing means making it possible to vary an association between the converters and the loads, an energy storage element. According to the invention, if for a first of the power centers, the regenerated power cannot be dissipated in the other loads associated with the first center, the regenerative load dissipates its power toward the bus of the second power center.

Abstract: There is provided a semiconductor device including: a current generation circuit that generates a current; a voltage generation circuit that, using the current generated by the current generation circuit, generates and outputs a predetermined voltage from a reference voltage, with an internal capacitor element that is connected to output of the voltage generation circuit, the internal capacitor element being provided within an integrated circuit on which the device itself is mounted; a storage section that stores a flag indicating a connection state between the output of the voltage generation circuit and an external capacitor element provided externally to the integrated circuit; and a controller that, based on the flag, controls a current amount of the current used by the voltage generation circuit to generate the predetermined voltage.

Abstract: Systems and methods for light-load efficiency in displays may include a backlight driver circuit that may adjust a gate drive voltage provided to a gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) in the boost converter based on the load conditions of light-emitting diodes used to illuminate the display panel. The backlight driver circuit may also switch between two different voltage sources to further broaden a range of gate drive voltages available to drive the gate of the MOSFET in the boost converter. As a result, the backlight driver circuit may decrease gate drive losses associated with the MOSFET, thereby increasing the efficiency of the boost converter.

Abstract: A switch mode power supply system has a constant on-time signal generator, a logic circuit, a feedback circuit, a first ramp signal generator, a second ramp signal generator, a switch circuit having a power switch, and a comparator. A feedback signal from the feedback circuit is compensated by the first ramp signal generator, and a reference signal is compensated by the second ramp signal generator. The comparator compares the compensated feedback signal with the compensated reference signal to indicate an off time of the power switch while the constant on-time signal generator decides the on-time of the power switch.

Abstract: A power supply having an input and an output, includes a power converter coupled between the input and output of the power supply including at least one switch that is controlled by comparing a sensed voltage, the sensed voltage corresponding to a current flowing through the switch, to a reference voltage. A controller, in response to a change detected in a switching frequency of the switch, reduces audible noise generated by the power supply by at least one of: adjusting the reference voltage; adjusting the current sense voltage; or adjusting a resistance used to generate the sensed voltage.

Abstract: The present invention provides an off time control method and switching regulator using it. The current flowing through a switch is compared with a current threshold, and the switch is turned off if the current flowing through the switch is larger than the current threshold. The off time of the switch is determined by the load. The current threshold is variable at light load to prevent generating the audible noise and improve the whole efficiency.

Abstract: Representative implementations of devices and techniques determine when a dc to dc converter switches from a first mode of operation to a second mode of operation. The determination is based on a time interval representing a portion of a current waveform, which is measured and compared to a threshold value.

Abstract: There is provided a current controlling mode DC-DC converter that operates in a PWM mode or a PFM mode by adjusting a turned-on time of a gate depending on power consumption of a load. The DC-DC converter includes a first comparator that receives a first input voltage and a second input voltage and outputs a first output signal, a second comparator that receives a reference voltage for mode switching and the second input voltage and outputs a second output signal, and a first logic element that outputs a reset signal for turning off a gate at a point of time when both the first output signal and the second output signal are applied. Examples may also include additional elements to facilitate mode switching.

Abstract: A buck mode switching power supply under hysteretic control is provided. A fixed frequency pattern generator is operatively connected to the supply and configured to provide dynamic adjustment of the hysteretic threshold voltage level, resulting in the fixed frequency operation of the supply.

Abstract: An embodiment of a power supply includes an input node operable to receive an input voltage, an output node operable to provide a regulated output voltage, an odd number of magnetically coupled phase paths each coupled between the input and output nodes, and a first magnetically uncoupled phase path coupled between the input and output nodes. Such a power supply may improve its efficiency by activating different combinations of the coupled and uncoupled phase paths depending on the load conditions. For example, the power supply may activate only an uncoupled phase path during light-load conditions, may activate only coupled phase paths during moderate-load conditions, and may activate both coupled and uncoupled phase paths during heavy-load conditions and during a step-up load transient.

Abstract: Disclosed is a DC-DC converter, including: a switch unit configured to generate output voltage for driving a load; an output voltage monitoring unit including a reference voltage generator generating reference voltage and a reference voltage capacitor maintaining the reference voltage when power of the reference voltage generator is interrupted and configured to generate a signal for setting the output voltage as the reference voltage; a switch controlling unit configured to control the switch unit by being operated in a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode by using the signal of the output voltage monitoring unit; and a mode determining and power interrupting unit configured to set an operating mode of the switch controlling unit as the PWM mode or the PFM mode according to a magnitude of the load and interrupt power of the reference voltage generator when operated in the PFM mode.

Abstract: A switching power-supply device includes a main switching element connected between a power-supply and an output terminal; a driving circuit that drives the main switching element; a capacitor that feeds power to the driving circuit; a charging circuit that charges the capacitor when the main switching element is switched from an on-state to an off-state; a switching control circuit that performs switching control of alternately switching the main switching element to the on-state and the off-state via the driving circuit; a voltage detection circuit that detects a voltage between both ends of the capacitor, and a driving control circuit that switches a state of prohibiting driving of the main switching element and a state of permitting driving of the main switching element, based on a difference between an output voltage output from the output terminal and a preset reference voltage and the voltage between both ends of the capacitor.

Abstract: A hold-up circuit coupled to a first node to receive an input voltage and to provide a hold-up voltage includes an inductor, a constant on-time buck-boost control circuit configured to drive a high-side power switch and a low-side power switch to operate in a buck mode and a boost mode of operation, and an energy storage capacitor. When the input voltage is greater than a predetermined threshold, the buck-boost control circuit is configured in the boost mode to drive the low-side power switch with constant on-time pulses and to charge the energy storage capacitor under non-synchronous operation. When the input voltage is less than a predetermined threshold, the buck-boost control circuit is configured in the buck mode to drive the high-side power switch with constant on-time pulses and to drive the low-side power switch under synchronous operation to provide the hold-up voltage to the first node.

Abstract: Generally, this disclosure provides methods and systems for improved startup for DC-DC converters that reduce input voltage droop, in-rush current and output voltage jumps. The system may include a power stage circuitry including a plurality of power segments coupled in parallel, the power stage circuitry is coupled between an input voltage and output stage circuitry and configured to deliver power to a load coupled to the output stage circuitry. The system may further include PWM and power stage controller circuitry configured to sequentially and progressively activate the plurality of power segments to limit an input in-rush current from the input voltage during a ramp up period and output voltage at the output stage circuitry.

Abstract: A power controller has a high-side driver, a low-side driver, a voltage divider, and a comparator. The high-side driver drives a high-side power switch, powered by a boost power line and a connection node. The low-side driver drives a low-side power switch, powered by an operation power line and a ground power line. The voltage divider has a first resistor having a first node for providing a detection voltage and a second node coupled to the boost power line or the connection node. The voltage divider has a second resistor coupled between the first node of the first resistor and the ground power line. When the low-side power switch is turned off, the comparator compares the detection voltage with a reference voltage. When the detection voltage is higher than the reference voltage, the comparator renders to turn on the high-side power switch.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to, the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: A circuit and method for operating a switching mode power supply. A clock is driven by a current source to generate pulses at a fixed frequency using pulse width modulation for normal load demands. For light load demands, the current to the clock is reduced, and therefore the clock generates pulses at a lower, variable frequency and fixed duration using pulse frequency modulation. Thus, depending on the load condition, either fixed frequency pulses or fixed duration pulses are automatically provided to a power stage for conversion to an output voltage.

Abstract: A method for operating a direct current (DC) motor is shown and described. The method includes using pulse width modulated (PWM) DC output to control the speed of the DC motor. The method further includes sensing current output to the motor. When the sensed current exceeds a threshold, the method holds the PWM DC output off.

Abstract: An electronic switch is connected in series with a load dependent on an input signal. The electronic switch is operated in a first operation mode for a first time period after a signal level of the input signal has changed from an off-level to an on-level. The first operation mode includes driving the electronic switch dependent on a voltage across the load and dependent on a temperature of the electronic switch. The electronic switch is operated in a second operation mode after the first time period. The second operation mode includes driving the electronic switch dependent on the temperature according to a hysteresis curve.

Abstract: A system including a switch configured to supply power to a load. A first comparator is configured to compare a first current through the switch to a first threshold. A second comparator is configured to compare the first current through the switch to a second threshold. The second threshold is greater than the first threshold. A current control module is configured to turn off the switch (i) for a first duration in response to the first current through the switch being greater than or equal to the first threshold and (ii) for a second duration in response to the first current through the switch being greater than or equal to the second threshold. The current control module is configured to adjust the second duration based on a difference between an estimated current through the load and a desired current through the load.

Abstract: A direct current-to-direct current (DC-DC) power supply includes a voltage converter module that converts an input voltage having a first voltage level into an output voltage having a second voltage level that is less than the first voltage level. An over-voltage detection module receives the second voltage and generates an over-voltage signal indicating an over-voltage condition of the DC-DC power supply. A shutdown module receives the over-voltage signal and generates a shutdown signal in response to the over-voltage condition. An over-voltage protection module interposed between the shutdown module and the input of the voltage converter module. The over-voltage protection module is configured to selectively inhibit delivery of the input voltage to the voltage converter module in response to the shutdown signal.

Abstract: An active power factor correction (PFC) circuit for calibrating a power factor of an AC-to-DC converter when the active PFC circuit is coupled with the AC-to-DC converter is disclosed including: a piecewise linear gain circuit, an error amplifier, a PWM controller, and a PWM signal generator. The piecewise linear gain circuit is for receiving a feed forward signal and generating a corresponding gain signal, wherein the gain signal and the feed forward signal have a broken line relation with respect to magnitude. The error amplifier is for generating an error signal according to an output voltage of the AC-to-DC converter. The PWM controller is for generating a control signal according to the gain signal and the error signal. The PWM signal generator is for generating a PWM signal for controlling a power switch of the AC-to-DC converter according to the control signal.

Abstract: A feedback loop, which feedbacks information of an output voltage or a load current, is provided. The feedback loop has a first mode, which digitalizes and feedbacks the information of the current voltage or the load current, and a second mode, which feedbacks the information as an analog value.

Abstract: A power supply system and method are disclosed. The system includes a switching stage to provide an output current through an output inductor in response to a switching signal having a substantially fixed duty-cycle. The system also includes a load monitor to monitor a load of the power supply system. The system further includes a gate drive controller to generate the switching signal and to change operation of the switching stage from a normal operating mode to a light-load operating mode in response to the load being less than a predetermined threshold to substantially minimize a voltage across the output inductor in the light-load operating mode.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: The present invention relates to a switch controller, a switch control method, and a power supply including the switch controller. An exemplary embodiment of the present invention detects an on-time of a power switch of the power supply and decreases a frequency of a clock signal according to a period during which the detected on-time is shorter than or equal to the minimum on-time. According to the exemplary embodiment, switching of the power switch is controlled according to a clock signal, and the minimum on-time is an on period of the power switch that cannot be shortened.

Abstract: A buck voltage converting apparatus is disclosed. The buck voltage converting apparatus includes a first transistor, a second transistor, an inductor, a controller and a switch. The first transistor receives an input voltage. A first terminal of the inductor is coupled to the first and second transistors. A second terminal of the inductor is coupled to an output terminal of the buck voltage converting apparatus for generating an output voltage. The controller receives the output voltage, and generates a detection voltage according to voltage amplitude of the output voltage. The switch is coupled between a first terminal of the first transistor and a control terminal of the second transistor. The switch is turned on or off according to the detection voltage.

Abstract: A low power DC-DC converter includes a converter stage coupled to an input node, and having a low side switch and a rectifier switch. A peak current detector senses a current at the low side switch and a zero current detector senses a current at the rectifier switch. It is configured to set the low side switch to a non-conductive state and the rectifier switch to a conductive state if the peak current detector detects a predetermined peak current. It is configured to set the rectifier switch to a non-conductive state if the zero current detector detects zero current at the rectifier switch. A time interval between subsequent current peaks is triggered by a charge comparator receiving an average current fed to the low side and rectifier switches from the input node and a reference current coupled to the charge comparator by a reference current source.

Abstract: Reducing current harmonics at light loads is disclosed. In an example, a method includes increasing output voltage of a boost converter to reach a higher potential in a low power mode. After reaching the higher potential, the method includes dropping a set point for the output voltage.

Abstract: There is provided a circuit including a capacitor, a current source configured to supply a current to the capacitor, a comparator configured to output a result of comparison between a voltage stored in the capacitor and a predetermined voltage, and a switch section configured to intermittently which is caused to flow to the capacitor by the current source.

Abstract: A power supply circuit includes a first switch, a second switch, an inductor, a series circuit, a second resistor, and a control signal circuit. The first and second switches are connected between a first terminal and a second terminal and to each other at an output node. The inductor is connected between the output node and an output terminal. The series circuit is connected in parallel with the inductor and includes a first resistor and a capacitor connected to each other at a common connection node. The second resistor is connected in parallel with the capacitor. The control signal circuit compares a voltage at the common connection node to a reference voltage to generate a control signal for at least the first switch based on the comparison.

Abstract: A device, system, and method for global maximum power point tracking comprises monitoring an output power of a DC power source while executing a maximum power point tracking algorithm and adjusting a maximum power point tracking command signal in response to the output power being less than a reference output power. The command signal is adjusted until the output power exceeds a previous output power by a reference amount. The command signal may be a voltage command signal, a current command signal, an impedance command signal, a duty ratio command signal, or the like.

Abstract: A voltage regulator that includes a high-side and a low-side power transistor is implemented where the high-side and the low-side power transistors are operable to output power to a transient load. The voltage regulator further includes control circuitry coupled to the high-side low-side power transistors and the transient load, with the control circuitry operable to receive a control signal from the transient load or the system. The control signal may correspond to an operating voltage of the transient load. In response to a decrease in a power level, the control circuitry may turn off the high-side power transistor, turn on the low-side power transistor a first duration, and turn off the low-side power transistor for a second duration. The first duration and the second duration may be based, at least in part, on the operating voltage.

Abstract: An off-line regulator has a rectification circuit configured to rectify an AC line voltage into a rectified line voltage, a pass device coupled between the rectified line voltage and a first capacitor, and a converter. The pass device is configured to be turned ON or OFF according to a comparison signal indicating whether the rectified line voltage is over a threshold voltage. The first capacitor delivers an interim voltage into the converter which supplies power to a load. Wherein a second capacitor coupled across a driver which driving the pass device is charged by the first capacitor when the comparison signal is at a first state, and the driver is boosted when the comparison signal is at a second state.

Abstract: A direct current to direct current (DCDC) voltage converter is described comprising a controller and at least one converter circuit. The converter circuit comprises at least first and second inductors, each having an input and an output; a first input switch connected to the input of the first inductor; a second input switch connected to the input of the second inductor; and an output switch connected to the outputs of the inductors for selectively combining the outputs to form a parallel combination of the inductors or a series combination of the inductors. The controller generates signals for selectively connecting the first and second input switches and the output circuit between a pair of power supply input terminals and a pair of power supply output terminals. In response to appropriate signals from the controller, the converter circuit can be operated as a buck converter or a boost converter.

Abstract: A power supply controller is connected between a power source and a power-supply path, and includes a switch circuit, a power-supply path protection circuit, and a sleep mode setting circuit. The switch circuit is configured to permit and inhibit power supply from the power source to the load. The protection circuit controls switching operation of the switch circuit according to a power-supply command signal commanding start or stop of the power supply to the load, calculates a temperature of the power-supply path regardless of whether power is supplied to the load, do not calculate the temperature of the power-supply path in a sleep mode, and inhibits power supply to the switch circuit according to the calculated temperature reaching an upper limit. The sleep mode setting circuit sets the power supply controller to the sleep mode according to the power-supply path satisfying a temperature condition.

Abstract: A controller for use in a power converter includes a load sensing circuit coupled to output an error signal in response to a feedback signal representative of an output of the power converter. The error signal is representative of a load coupled to an output of the power converter. A burst mode control circuit is coupled to output a burst mode control signal in response to the error signal. An offset current generator circuit is coupled to output an offset current in response to the error signal. A drive circuit is coupled to control switching of a power switch to control a transfer of energy from an input of the power converter to the output of the power converter in response to the error signal, the burst mode control signal, the offset current, and a current sense signal representative of a current through the power switch.

Abstract: A switching-control circuit to control switching of a transistor whose input electrode is applied with an input voltage, and turn off the transistor, when an output current from the transistor is greater than a reference current, includes: a reference-voltage-generating circuit to generate such a first-reference voltage that the reference current is reduced with reduction in an output voltage; a comparing circuit to compare a voltage corresponding to the output current with the first-reference voltage; and a driving circuit to turn on/off the transistor based on a feedback voltage corresponding to the output voltage and a second reference voltage corresponding to a target level so that the output voltage reaches the target level, when the comparing circuit determines that the output current is smaller than the reference current, and turn off the transistor when the comparing circuit determines that the output current is greater than the reference current.

Abstract: A converter and a method for controlling a converter are disclosed herein, in which the converter includes a converting circuit, a current sensing circuit, a digital-to-analog converting circuit, a slope compensation circuit and a comparator circuit. The slope compensation circuit is independent from the digital-to-analog converting circuit, and the slope compensation circuit exclusively generates an analog slope compensation signal. The comparator circuit compares an analog signal generated by the digital-to-analog converting circuit with the superimposition of the analog slope compensation signal and a current sensing signal generated by the current sensing circuit or compares the current sensing signal with the superimposition of the analog slope compensation signal and the analog signal to generate a comparator output signal for a control operation of the converting circuit.

Abstract: A power conversion circuit of two feedback loops is disclosed that includes a feedback control circuit for ramping up or down a commanded voltage to a load (e.g., LEDs). The second feedback loop feeds into the first feedback loop, and the second feedback loop operates at a slower bandwidth than the first feedback loop. When ramping up or down the commanded voltage, a voltage overshoot results because of delay in the system. The overshoot can be compensated for by a final adjustment to the commanded voltage.

Abstract: According to one embodiment, a synchronous buck converter comprises a multi-mode control circuit for detecting a load condition of a variable load, an output stage driven by the multi-mode control circuit, wherein the variable load is coupled to the output stage, and a feedback circuit connected between the output stage and the multi-mode control circuit. The multi-mode control circuit is configured to adjust a current provided by the output stage to the variable load based on the load condition. In one embodiment, the multi-mode control circuit selectably uses one of at least a first control mode and a second control mode according to the load condition, wherein the first control mode is a pulse-width modulation (PWM) mode selected for switching efficiency when the load condition is heavy and the second control mode is an adaptive ON-time (AOT) mode selected for switching efficiency when the load condition is light.

Abstract: An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit compares a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit outputs a switching signal having a switching period to control a switch to regulate an output of the power converter in response to the feedback signal and enables or disables a switching period based on the output of the feedback circuit. The adjustable voltage reference circuit adjusts the voltage reference by a first amount in response to a first number of disabled switching periods indicating a first load condition at the output of the power converter and by a second amount in response to a second number of disabled switching periods indicating a second load condition at the output of the power converter.

Abstract: A power converting circuit and a feedback control circuit for the power converting circuit are disclosed. The feedback control circuit comprises a feedback controller and a level controlling unit. The feedback controller generates a feedback control signal according to a reference voltage signal and a feedback signal. The level controlling unit receives one of the reference voltage signal and the feedback signal and modules a level of the received signal from a first level to a second level with time according to a level adjusting signal.

Abstract: There is provided a control device which controls a transformer in accordance with a total loss imposed on a load driving system including the transformer and a load.