Abstract: The present invention discloses a power factor correction circuit, a control circuit therefor and a method for driving a power factor correction circuit. The power factor correction circuit receives rectified power obtained by rectifying AC power, and corrects the power factor thereof. The power factor correction circuit includes an inductor, and it generates a reference signal as a limit for the inductor current. The reference signal is proportional to Comp/Vin, wherein Comp is a signal relating to a feedback signal, and Vin is a voltage signal relating to the AC power or the rectified power.

Abstract: The switching frequency of a switch mode PFM power converter is compared with a predetermined frequency range that contains the operating frequency of a nearby clocked sub-system. In response to the switching frequency coming into the range, a parameter of the power converter is changed from an original value, so as to cause the switching frequency to go out of the range.

Abstract: A switching regulator switch between an input terminal and an output terminal; a second switch between the output terminal and ground; a switching-time control circuit to generate a first signal when a first period corresponding to a ratio of ON-period of the first switch to a sum of those of the switches has elapsed from a reset-release timing and a reset signal when a second period longer than the first period has elapsed from the rest-release timing; a comparator to generate a second signal when a feedback voltage is smaller than a reference voltage; and a switch control circuit to control the switches so that the first switch is turned off and the second switch is turned on in response to the first signal, and the second switch is turned off and the first switch is fumed on in response to the second signal.

Abstract: An integrated circuit device for delivering power to a load includes a controller circuit, a cascade circuit, and a power delivery circuit. The controller circuit generates a plurality of control signals. The cascade circuit receives the control signals from the controller circuit and sequentially outputs the control signals onto a cascade bus. The power delivery circuit receives the control signals from the controller circuit and delivers an amount of current to the load, in response to one of the control signals.

Abstract: A power supply device includes, for example, a switching element, a rectifying circuit having a first rectifying element, and a control circuit which controls an output of the rectifying circuit. In particular, the power supply device includes a detection unit which detects a current flowing through the first rectifying element, and an output reduction unit which reduces the output of the rectifying circuit as an output of the switching power supply device. The output reduction unit changes a switching state of the switching element when the detection result of the detection unit exceeds a predetermined value.

Abstract: There is disclosed a converter controller which can simply and early detect an abnormality of an auxiliary circuit constituting a soft switching converter. On turning off a first switching element, a controller detects a voltage between both the ends of a snubber capacitor and a voltage between both the ends of the first switching element, to obtain a difference voltage. The controller compares the obtained difference voltage with a voltage threshold value stored in a memory (not shown) to judge whether or not the difference voltage is larger than the voltage threshold value. When the difference voltage is smaller than the voltage threshold value, the controller judges that an auxiliary circuit is normal, to end processing, whereas when the difference voltage is not less than the voltage threshold value, the controller judges that a failure (an open failure) occurs in the auxiliary circuit, to shift to a fail safe operation, thereby ending the processing.

Abstract: A method for controlling a switching voltage regulator that includes generating a feedback voltage that is proportional to the output voltage of the voltage regulator; generating a voltage proportional to the duty-cycle of the inductor charging and discharging phases as a function of the difference between the feedback voltage and a reference voltage; and adding a dominate pole and two zeros to the function used to generate the voltage proportional to the duty-cycle of the inductor charging and discharging phases.

Abstract: The synchronous switching power converter comprises an inductor; a down bridge transistor; and a zero current detection circuit comprising a zero current comparator for receiving a fixed comparing level at a negative input end for comparison to change state of a comparing result; a delay unit, for delaying the comparing result to change state of a turn off signal according to a compensation voltage, to turn off the down bridge transistor when determining current on the inductor is zero; a transient state adjusting circuit for indicating a transient period when detecting state of the turn off signal is changed; and an integrator for integrating the compensation voltage by analog manner to adjust value of the compensation voltage and providing to the delay unit within the transient period; wherein the zero current comparator determines the integrator to integrate positively or negatively within the transient period.

Abstract: A time off estimator and an adaptive controller implemented on an integrated circuit to emulate current dependent zero crossing circuitry to permit improved performance of a buck type switching mode power supply. The time off estimator circuit is enhanced by an automatic correction circuit for the timing of a zero crossing where energy to a reference capacitor returns to zero and is turned off awaiting the next cycle where the capacitor is again charged and discharged.

Abstract: A timing generator for a power converter is provided. The timing generator includes a threshold voltage generation circuit and a timing generation unit. The threshold voltage generation circuit receives an error signal related to an output voltage of the power converter. The threshold voltage generation circuit generates a threshold voltage according to the error signal. The timing generation unit generates a timing signal according to the error signal, the threshold voltage and a control signal. The timing generation unit provides a tracking signal. A width of the timing signal depends on a time when tracking signal departed from a level of the error signal to a level of the threshold voltage. The present invention also provides a timing signal generation method for the power converter.

Abstract: A method for soft-starting a voltage generator includes disabling an output driver; detecting the voltage on an output node; ramping a reference voltage at a controlled rate from a predetermined first level until the reference voltage reaches a second level that is a predetermined function of said output node voltage; enabling the output driver when the reference voltage reaches said second level; and then ramping the reference voltage and the output node voltage at a controlled rate to a boot voltage level. A soft-start circuit for an output voltage generator includes a comparator for causing a ramp generator to ramp the reference voltage and the voltage on the output node to a boot voltage level at a controlled rate once the comparator detects that the reference voltage is substantially equal to the voltage on the output node.

Abstract: Systems and methods are disclosed to control a buck converter with a first switching circuit including a first upper power transistor coupled to a first lower power transistor at a first junction; a second upper power transistor coupled to a second lower power transistor at a second junction; an inductor coupled to the first and second junctions; and a load coupled to the second junction.

Abstract: An error amplifier includes a difference amplifier providing an error signal representing a difference in voltage between a feedback signal and a reference signal. The error amplifier further includes a compensation circuit limiting the rate of change of the error signal. The compensation circuit includes a switch that when activated effectively removes a circuit portion from the compensation circuit. A switch signal indicates for the switch to be activated when the feedback signal exceeds the reference signal by a predefined amount. The compensation circuit may further include a second switch that when activated effectively removes a second circuit portion from the compensation circuit. A second switch signal indicates for the second switch to be activated when the feedback signal exceeds the reference signal by a second predefined amount.

Abstract: A DC-DC converter has a control circuit for controlling a high-side power transistor and a low-side power transistor connected in series between supply terminals to which an input supply voltage is applied. The converter has a switching node at the interconnection of the power transistors for connection of an inductor to which a load is connected. The control circuit has a feedback loop that provides a pulse width modulated control signal, logic circuitry to which the pulse width modulated control signal is applied and gate drivers with inputs connected to outputs of the logic circuitry and outputs applying gate drive signals to the gates of the power transistors. A digital signal is obtained which is indicative of whether the converter switching node is at a potential above or below a zero reference at the time of the turn-off edge of the low-side gate drive signal.

Abstract: A control circuit of a DC-DC converter that has a switching element, including an error amplifier that amplifies a difference between a reference voltage and a feedback voltage corresponding to an output voltage of the DC-DC converter, a voltage reduction comparator that outputs an interrupt signal when the feedback voltage is lower than a voltage reduction threshold that has a value lower than that of the reference voltage, and a pulse-width modulation (PWM) signal generator circuit. The PWM signal generator circuit generates a PWM signal of a predetermined frequency based on the voltage difference when no interrupt signal is generated, or otherwise generates a switch drive signal to activate the switching element for a first period of time corresponding to the difference output by the error amplifier, and to deactivate the switching element for a second period of time after the first period of time has elapsed.

Abstract: A switching regulator has an output circuit having first and second transistors and a connection node thereof as an output terminal; a switching control unit generating a first and second switching pulses for alternately switching the first and second transistors according to the load; and a first comparator monitoring an output voltage, and generating a pulse stopping control signal for stopping the generation of the switching pulses when the output voltage rises, and for generating the switching pulses when the output voltage drops. And the switching control unit performs a stopping operation for stopping the switching pulse generation and a switching operation for generating the switching pulse in response to the pulse stopping control signal, and outputs, to the first comparator, a timing control signal for quickening a switching timing from the stopping operation to the switching operation as the load of the load circuit increases.

Abstract: Generally, this disclosure describes an apparatus, systems and methods for adaptively controlling a voltage regulator.

Abstract: A DC-DC converter circuit includes a DC-DC converter IC that inputs, via an input terminal connected to a power supply input line, a direct-current voltage converted from an alternating-current voltage and supplied by the power supply input line. The DC-DC converter IC outputs a direct-current voltage having a value converted by operation of the DC-DC converter IC. The DC-DC converter IC is able to operate when a voltage of a specified threshold value or greater is input from an enable terminal. The DC-DC converter circuit also includes an enable control circuit that makes the voltage input to the enable terminal equal to the threshold voltage or greater when the direct-current voltage supplied from the power supply input line reaches a specified value.

Abstract: A semiconductor integrated circuit device is employed in a DC-DC converter that switches the voltage fed to the load depending on the PWM signal. The semiconductor integrated circuit device has an error voltage generating part, a mode setting part, an oscillation signal generating part, a pulse generating part, and a control part. The oscillation signal generating part generates an oscillation signal with a prescribed period when in the non-light-load mode, and it turns off the oscillation signal when in the light-load mode. The pulse generating part generates a pulse signal before the oscillation signal generating part generates the oscillation signal when the pulse generating part switches from the light-load to the non-light-load mode.

Abstract: A boost-type switching regulator includes an inductor; a rectifying element; a capacitor; a switching element; an output terminal; a detection voltage generating unit; an output voltage controlling unit; and a detection voltage level shifting unit. The detection voltage generating unit generates a detection voltage according to an output voltage. The output voltage controlling unit turns on and off the switching element to increase the output voltage when the detection voltage is smaller than a specific value, and to turn off the switching element to decrease the output voltage when the detection voltage is greater than the specific value. The detection voltage level shifting unit shifts the detection voltage so that the detection voltage during a voltage increasing period becomes greater than the detection voltage during a voltage decreasing period.

Abstract: A power supply apparatus includes a first power factor correction circuit, a second power factor correction circuit and a control circuit that includes a first switching control unit that outputs a first switching signal for controlling a first switching element of the first power factor correction circuit generated in accordance with a detected result by an output voltage of the first power factor correction circuit and a current flowing through the first switching element, and a second switching control unit that outputs a second switching signal for controlling a second switching element of the second power factor correction circuit generated in accordance with a detected result by an output voltage of the second power factor correction circuit and a current flowing through the second switching element.

Abstract: Systems and methods for regulating a switching converter are disclosed. One embodiment of the present invention relates to a power supply system that includes a switching converter that provides an output voltage by alternately turning on and off a high-side transistor and a low-side transistor both coupled to an output inductor through a switching node. The switching converter includes a drive circuit that regulates the output voltage based on a feedback signal. The power supply system also includes a simulated output generator that generates and provides the drive circuit with a simulated inductor waveform as the feedback signal based on a low-side output waveform of the low-side transistor measured at the switching node during off-times of the switching converter.

Abstract: A power supply device is provided with the following: a rectifier circuit that rectifies an alternating voltage from an alternating current source; a booster circuit that boosts the voltage after rectification, and generates an input side voltage of a voltage conversion unit; the voltage conversion unit that outputs a voltage required for reducing the input side voltage and supplying the input side voltage to a light source; a voltage current detection unit that determines whether or not the light source is connected; and an output voltage control unit that, if it is determined that a first resistor and a second resistor, which are connected in parallel with respect to the light source, and the light source are not connected, controls the voltage of the first resistor so that the voltage is no more than a prescribed value.

Abstract: A converter circuit may include: a first node receiving an input voltage; a second node providing an output voltage; a first inductor between the first node and a third node; a capacitor between the third node and a first terminal of a diode, the other terminal of the diode providing said output voltage; a second inductor between the first terminal of the diode and common; an electronic switch acting between the third node and common; a first current generator acting between the first node and the switch to drive the switch to the conductive condition; and a second current generator sensitive to the current through the switch in the “on” condition and/or the output voltage on the second node, the second current generator to draw current from the first current generator to drive the switch to the non-conductive condition.

Abstract: A current mode buck converter has a power stage and a feedback stage. The power stage converts a higher power supply voltage level to a lower output voltage level. The feedback stage is connected with the power stage for controlling the levels of repetitive switching of an output current by phase and frequency locking a switching frequency of the output current to an external clocking signal. The feedback stage controls two levels of output current bounds by transforming a current error to a phase error to prevent error amplification such that an average output current remains constant at any duty cycle.

Abstract: A regulator includes a transistor connected between an input and an output. A feedback voltage controls the transistor to keep the output voltage constant. A first circuit functions as a comparator to compare a detection voltage from the output of the transistor and the feedback voltage when the output current is higher than a predetermined value, and functions as a buffer when the output current is lower than the predetermined value. A second circuit receives a reference voltage, the feedback voltage, and an output from the first circuit, and generates (i) a difference between the feedback voltage and the first circuit output when the reference voltage is lower than the first circuit output, and (ii) a difference voltage between the feedback voltage and the reference voltage when the reference voltage is higher than the first circuit output, and supplies a control voltage to control the output of the transistor.

Abstract: An apparatus and method of generating a drive signal for a switch in a switching converter having input terminals for applying an input voltage, output terminals for providing an output signal, and at least one inductive storage element coupled to the switch. The method includes sampling the output signal to provide a sampled output signal, and generating a pulsewidth modulated drive signal having a duty cycle that is dependent on the sampled output signal, wherein the output voltage is sampled at sampling times that are dependent on the duty cycle.

Abstract: In an embodiment, a voltage conversion circuit includes a first voltage conversion unit stepping up or stepping down an input DC voltage and a second voltage conversion unit stepping up or stepping down an input DC voltage. A switcher is configured to switch between using both the first and second conversion units or just one of the first and second conversion units. The switcher can optionally be controlled according to an input voltage level such that both the first and second voltage conversion units can be used for a voltage step-up or voltage step-down operation or just one of the first and second voltage conversion units can be used.

Abstract: According to one embodiment, a power supply circuit includes: a DC-DC converter which converts a first DC voltage supplied from a power supply flow path into a second DC voltage having a different absolute value, to supply the voltage to a DC load; and an overcurrent protection unit which is electrically connected to an end portion of the DC load on a low potential side, and performs feedback control of the DC-DC converter based on current which flows to the DC load. The DC-DC converter includes a normally-on type switching element. The overcurrent protection unit is electrically connected to the third electrode. When the current which flows to the DC load is greater than a reference value, the overcurrent protection unit changes the state of the switching element from the first state to the second state by decreasing the potential of the third electrode.

Abstract: Apparatus and methods for generating a drive signal of a switching signal are disclosed. A first circuit receives an oscillating reference signal, a first compensation signal, a second compensation signal, and a third compensation signal. The first compensation signal is indicative of an error between an output voltage of a power converter and a reference voltage. The second compensation signal is indicative of the error relative to a threshold. The third compensation signal is indicative of an output current of the power converter. The first circuit generates a comparison signal having a waveform including pulses having durations based at least partly on a combination of the periodic reference signal, the first compensation signal, the second compensation signal, and the third compensation signal. A second circuit receives a clock signal and the comparison signal and generates a drive signal for activation and deactivation of a driver transistor.

Abstract: A control device is disclosed, having a signal generating circuit and a mode decision circuit. The signal generating circuit is used to generate a first control signal and a second control signal according to an output voltage of a buck-boost converter. The first control signal is used to conduct a first switch and a second switch of the buck-boost converter. The second control signal is used to conduct a third switch and a fourth switch of the buck-boost converter. When the duty cycle of the first control signal is greater than a first predetermined value and the duty cycle of the second control signal is less than a second predetermined value, the mode decision circuit configures the signal generating circuit to generate the first control signal and the second control signal with substantially the same duty cycle.

Abstract: The present invention discloses a switching regulator, a control circuit and a control method therefor. The switching regulator comprises an upper gate switch, a lower gate switch, and an inductor connected to a switching node. When a current passing through the upper gate switch or the inductor is lower than a threshold, the lower gate switch is kept OFF until a next cycle, and during the cycle wherein the lower gate switch is OFF, the upper gate switch is turned ON for a period of time.

Abstract: In a PWM signal generation method of a voltage regulator, an output sense signal, a first ramp signal and a second ramp signal are provided. A first time point of the first ramp signal crossing with the output sense signal is used to determine a start point of an ON-time of a PWM signal, and a second time point of the second ramp signal crossing with the output sense signal is used to determine an end point of the ON-time of the PWM signal. Moreover, the first ramp signal is reset to a reference voltage at the first time point and then maintained at the reference voltage, and further ramps down starting from the end point of the ON-time. The second ramp signal ramps up starting from the start point of the ON-time, and then is reset to a preset voltage at the second time point.

Abstract: A first transistor coupled between a power supply line and an inductor, a second transistor coupled between a source of the first transistor and a reference voltage line, and a third transistor coupled between the source of the first transistor and a load are included, and efficiency deterioration caused by a dead time is improved by keeping a current flow through a current path of an inductor, a load, and the third transistor during the dead time by supplying a voltage which is less than a threshold voltage and approximately the threshold voltage to a gate of the third transistor as a gate voltage.

Abstract: Exemplary embodiments are related to a switching voltage regulator. A switching voltage regulator may include a current limit detector configured to detect an over-current condition. The switching voltage regulator may further include a pulse-width modulation (PWM) module coupled to the current limit detector and configured to convey a PWM signal based on a programmed switching frequency and an output voltage and in response to the over-current condition.

Abstract: A method and apparatus for determining the entry and exit from a pulse skipping mode in a power supply is provided. The power supply may incorporate a buck regulator. The method begins when current is sensed at an inductor of a power supply. This sensed current is then compared with a predetermined threshold current value. If the comparison reveals that the current is below the predetermined threshold current value, a pulse skipping mode is entered. If the current is found to be above the predetermined threshold the pulse skipping mode is not entered and normal operation continues. The apparatus includes a transconductance amplifier, an offset voltage source, a reference power supply reference voltage source, first and second voltage comparators, and a processor.

Abstract: A buck switching regulator includes a feedback control circuit including a feedback network including first and second gain circuits configured to generate first and second feedback signals, respectively, indicative of the regulated output voltage; a ripple generation circuit configured to inject a ripple signal to the first gain circuit; an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a reference signal and to generate an output signal being coupled to the first gain circuit to adjust the first feedback signal; and a comparator configured to receive the first feedback signal and the reference signal and to generate a comparator output signal. The output signal of the OTA is applied to the first feedback signal to cancel a voltage offset in the regulated output voltage due to the injected ripple signal to the first gain circuit.

Abstract: A switching regulator includes a first switching element connected between an input terminal and an output terminal; a second switching element connected between the output terminal and a ground; a switching-time control circuit to generate a first switching-time control signal indicating finish timing of an ON-period of the first switching element, based on a ratio of a length of the ON-period of the first switching element to a sum of lengths of ON-periods of the first and second switching elements; a comparator generate a second switching-time control signal indicating finish timing of the ON-period of the second switching element when a feedback voltage is smaller than a reference voltage; and a switching-element control circuit to control switching of the first and second switching elements so that the first and second switching elements are turned on complementarily based on the first and second switching-time control signals.

Abstract: The disclosure provides a power factor correcting (PFC) circuit, a power supply and a method of manufacturing a power converter. In one embodiment, the PFC circuit has a positive input terminal, an output terminal and a ground terminal and includes: (1) a power factor inductor coupled in series between the positive input terminal and the output terminal, (2) a main switch configured to periodically connect the power factor inductor to the ground terminal and (3) a clamping capacitor coupled to the power factor inductor and configured to provide zero turn-off loss for the main switch.

Abstract: DC to DC converters are described that include two converters interconnected and operated to mitigate at least some of the effects of low duty cycle operation.

Abstract: A non-isolated type switching regulator having an inductor includes: a switch element; a rectification element; an error amplifying circuit section amplifying a voltage difference between a feedback voltage and a first reference voltage and outputting as an error voltage; a first voltage comparison circuit section performing a voltage comparison of a ramp voltage which performs a voltage change set beforehand with the error voltage to be synchronized with the switching of the switch element and producing and outputting a first comparison signal; a second voltage comparison circuit performing a voltage comparison of the error voltage with a second reference voltage and producing and outputting a second comparison signal; an oscillation circuit section starting an oscillation based on the second comparison signal and producing and outputting a clock signal; and a control circuit section performing a switching control of the switch element based on the clock signal and the first comparison signal.

Abstract: A DC/DC converter 10 has a high-side transistor QH as a switching element and a low-side transistor QL as a synchronous rectifier element. A first primary electrode D and secondary primary electrode S of the high-side transistor QH are connected to an input voltage VIN and an external terminal T1, respectively. A detection transistor QD is provided in a row with the high-side transistor QH, and the ON voltage of the high-side transistor QH when ON is output as detection voltage VQD from the detection transistor QD. The output detection voltage VQD is added to a feedback voltage VFB1 by an adder CB, and inputted to a comparator CMP1. The ON period of a one-shot pulse PS1 outputted from the comparator CMP1 is regulated so as to be in direct proportion to the sum of the detection voltage VQD and the feedback voltage VFB1.

Abstract: A resonance frequency adjusting circuit in electronic communication with a power supply and a load connected to the power supply includes a first LC filter, a capacitor, a switch, and a frequency detecting and control module. The first LC filter circuit is electrically connected between the power supply and the load. The switch is electrically connected between the capacitor and ground. The frequency detecting and control module detects a current transient frequency of the load, compares the current transient frequency with a first resonance frequency of the first LC filter circuit, and controls the switch to turn on/off according to the comparison.

Abstract: A control circuit and method for a buck-boost switching converter provides a mode determinative circuit to judge the timing of an operation under buck-boost mode based on the input voltage, the output voltage and the mode reference voltage; meanwhile, the control signal generating circuit is provided to turn off the second switch during the first switch being on, turn on the second switch during the first switch being off, turn off the fourth switch during the third switch being on, turn on the fourth switch during the third switch being off, wherein the duty cycles of the first and third switches are identical, and duty cycles of the second and fourth switches are identical.

Abstract: A control system of a DC to DC converter skips switching pulses according to the output of an overvoltage protection circuit. The overvoltage protection circuit includes an overvoltage threshold voltage control section that lowers an overvoltage threshold voltage when the pulse width has a minimum valve. The control system both improves the output voltage accuracy of the DC to DC converter under a light load and promotes a quick return to normal operation after an overvoltage protection operation under a heavy load.

Abstract: A control circuit is provided for a buck converter that includes at least an inductor coupled to an output of the buck converter. The control circuit includes a power switch configured for coupling to a line voltage and configured for charging the inductor, an input line voltage sampling circuit, and a constant-voltage (CV) and constant-current (CC) control module coupled to the power switch. During a charging period of the inductor, the CV and CC control module is configured to control the power switch to provide a constant output current by maintaining a constant peak inductor current, even when the input line voltage changes. During a discharging period of the inductor, the CV and CC control module is configured to monitor the sensed output voltage to control the power switch to provide a constant output voltage.

Abstract: Embodiments described include voltage generators having reduced or eliminated cross current. Dynamic adjustment of a low or high threshold voltage used in a voltage generator is described. Use of a folded cascade amplifier in a voltage generator is also described.

Abstract: An electronic device for switched DC-DC conversion of an input voltage level into an output voltage level, comprising a first power switch and a second power switch, being connected in parallel and having a different gate width, and a driving stage that is configured to selectively drive the first power switch and/or second power switch depending on a load current output.

Abstract: A circuit for controlling a load current through a coil is connected to an output port of a transistor H-bridge that includes two low side transistors and two high side transistors. A current sense circuit is coupled to the H-bridge and configured to provide a representation of the load current provided by the output port. A current regulator is configured to generate a modulated signal dependent on the representation of the load current and a current set-point. The modulated signal has a duty-cycle. A gate control logic drives the individual transistors of the H-bridge on and off in accordance with the modulated signal. A direction signal provides the load current to the coil. The direction signal determines the direction of the load current. An over current detection circuit is coupled to each individual transistor and is configured to signal an over-current by providing an active over-current failure signal when a transistor current through the respective transistor exceeds a respective maximum value.

Abstract: A power supply circuit and a method for operating a power supply circuit involves selecting a normal operational mode or a pass-through operational mode for a switched mode power supply, in the normal operational mode, converting an input voltage of a power supply circuit to an intermediate voltage using a switching regulator of the switched mode power supply, in the pass-through operational mode, disabling the switching regulator such that the input voltage of the power supply circuit is unchanged by the switching regulator and an electric current consumption of the switching regulator approaches zero, and converting the intermediate voltage or the input voltage of the power supply circuit to an output voltage using a linear voltage regulator.