Abstract: Systems and methods for transition control in a hybrid Switched-Mode Power Supply (SMPS). In some embodiments, a hybrid SMPS may include linear circuitry configured to produce an output voltage proportional to a variable duty cycle when the SMPS operates in linear mode and hysteretic circuitry coupled to the linear circuitry, the hysteretic circuitry configured to cause the duty cycle to assume one of two predetermined values when the SMPS operates in hysteretic mode. The hybrid SMPS may also include transition circuitry coupled to the linear circuitry and to the hysteretic circuitry, the transition circuitry configured to bypass at least a portion of the linear circuitry in response to the hybrid SMPS transitioning from the hysteretic mode to the linear mode.

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: In accordance with an embodiment, a method for controlling a switched-mode power supply (SMPS), includes receiving a measurement of a supply voltage input of the SMPS, determining a change in the supply voltage input over time based on receiving the measurement, comparing the determined change in the supply voltage input with a predetermined threshold value and applying a correction factor to an integrator within a feedback control loop of the SMPS based on the comparing.

Abstract: The present invention includes: a zero crossing detection circuit which outputs a zero crossing signal when an inductor's regeneration period is completed; a light load detection circuit which compares an amplified error signal from an error amplifier and a threshold and outputs a light load signal; a timer circuit which outputs an intermittent operation enabling signal after a predetermined period based on the light load signal and zero crossing signal and outputs an intermittent operation disabling signal when the zero crossing signal is not outputted for a predetermined period; and an ON-OFF control controller which turns off a switching element when the amplified error signal falls below the threshold while the timer circuit is outputting the intermittent operation enabling signal, and turns on the switching element when the amplified error signal at least reaches or exceeds the threshold while the timer circuit is outputting the intermittent operation enabling signal.

Abstract: A hysteretic mode control circuit within a DC-to-DC converter is configured for varying the current limit that controls the switching interval and duration of a power switching section of the DC-to-DC converter to permit the DC-to-DC converter to manage large changes in output current load of the DC-to-DC converter. The hysteretic mode control circuit has a positive and a negative current limit section that develop a first and a second reference signal for turning on and turning off the first and the second switching device. The first and second reference signals are compared to an output voltage of the power switching section to determine if the first switching device or the second switching device is to be turned on or turned off.

Abstract: A converter comprises a high side switch, a low side switch connected in series with the high switch, a gate drive circuit comprising a first drive port coupled to a gate of the high side switch, a second drive port coupled to a gate of the low side switch, an SRE input port and a PWM input port coupled to a PWM controller, wherein the PWM controller is selected from the group consisting of a first PWM controller having two complementary PWM outputs, a second PWM controller having a tri-state PWM output and a third PWM controller having a single PWM output.

Abstract: Power converters that produce less noise are disclosed. For example, in an embodiment, power converter can include a first inductor magnetically coupled to a second inductor, wherein a first end of the second inductor is electrically open and a second end of the second inductor is electrically coupled to ground via a second capacitor, a transistor electrically connected to the first inductor, and control circuitry to control switching of the transistor, wherein when the transistor is repeatedly switched on and off by the control circuitry, a current loop is formed through the transistor, the second capacitor, the first inductor and the second inductor, the current loop causing a reduced amount of switching noise to be generated by the power converter.

Abstract: A method includes receiving, at a voltage regulator, an activity adjustment signal from a digital circuit. The method also includes controlling one or more variable impedance elements of the voltage regulator to modify an output voltage provided to the digital circuit. The output voltage is based at least in part on the activity adjustment signal.

Abstract: A switching power supply device includes a first control circuit that turns a first switch on when first and second switches are off and a voltage at a junction node therebetween is increased to decrease a voltage across the first switch to a first threshold voltage, turns off when a first ON-period has elapsed from when the first switch is turned on, and lengthens the first ON-period as an output voltage decreases relative to a reference voltage; and a second control circuit that turns the second switch on when both switches are off and a voltage across the second switch is decreased to a second threshold voltage, turns off when a reverse current flows through the inductor, sufficient to increase the voltage at the junction node to decrease the voltage across the first switch to the first threshold voltage after the second switch is turned off.

Abstract: A system and method capable of injection locking the phases of a peak-valley multiphase regulator includes comparing an output voltage error signal with a ramp control signal and providing a corresponding slope reset signal, using transitions of the slope reset signal to develop a equally spaced high side ramp signals and equally spaced low side ramp signals, and injecting a corresponding one of the high side signals and a corresponding one of the low side ramp signals into each of the phases which correspondingly develop equally spaced pulse control signals for multiphase operation. Such injection locking allows the additional phases to operate out of phase with the first phase and allows operation at high duty cycles.

Abstract: A switched mode power supply (SMPS) comprising a controller configured to control switching of the SMPS to regulate an output voltage at an output of the SMPS based on a feedback signal that indicates the output voltage, and a voltage droop control circuit. The voltage droop control circuit comprises a voltage droop control signal generator that detects a voltage drop across a component of the SMPS that is indicative of a current flowing through the output of the SMPS during operation. The voltage droop control signal generator is an active device arranged to generate, based on the detected voltage drop, an output voltage droop control signal for causing the controller to adjust the regulation of the output voltage. The voltage droop control circuit further comprises a reference voltage generator arranged to bias at least one of the first and second inputs of the voltage droop control signal generator.

Abstract: A switching regulator controller for a buck switching regulator incorporates a multi-mode adaptive modulator configured to automatically select between a first operation mode and a second operation mode as a function of the output voltage being generated. In one embodiment, the switching regulator controller compares the output voltage to a comparator reference voltage and is configured to operate in a selected operation mode based on the output voltage. In this manner, a single switching regulator controller can be used in multiple instances of an electronic system to supply circuitry that may have different operational requirements. In one embodiment, the switching regulator controller is configured to operation in a PWM/PFM mode and a PWM mode as a function of the output voltage, which indicates the circuit application to which the switch regulator controller is used to supply.

Abstract: A circuit for controlling a switching regulator is provided. The circuit includes a first input to receive a feedback signal from the switching regulator proportional to an output voltage of the switching regulator, a second input to receive a voltage reference signal, an output to be coupled to an input of the switching regulator, an error amplifier having a first input terminal coupled to the first input to receive the feedback signal, a second input terminal coupled to the second input to receive the voltage reference signal, and an output terminal coupled to the output, and a compensation network coupled between the second input and the output. The compensation network includes a series combination of a first capacitance and a first resistance coupled between the second input and a node, a second resistance coupled between the node and the output, and a second capacitance coupled to the node.

Abstract: A control circuit is adapted for controlling a converter. The converter includes a transformer and a power switch. The control circuit includes a current sensing unit, a current emulating unit, and a control unit. The current sensing unit senses a current flowing through the power switch coupled to a primary winding of the transformer. The current emulating unit determines a propagation delay period according to a voltage transient time of an auxiliary winding of the transformer and a turn-off time of the power switch, and retrieves several sampling times in a conduction period of the power switch according to the propagation delay period. The current emulating unit obtains a peak current and a valley current according to the sampling voltages corresponding to the sampling times. The control unit generates a control signal configured to control the power switch according to the peak current and the valley current.

Abstract: This device protects at least one electronic switching branch of an electrical conversion system against an overcurrent, each branch comprising two switching half-branches serially connected at an intermediate terminal, at least one half-branch including a switching member, each switching member comprising a first controllable switch and a diode connected in antiparallel to the first switch. The protection device includes, for each switching branch, at least one second controllable switch, each second switch being connected to the intermediate terminal or to an electrode of said diode in antiparallel to the first switch, each second switch being able to switch, under action of a controller, from an on state to an off state to protect said diode from the overcurrent, means for measuring a magnitude relative to a current able to circulate in each diode, and means for controlling each second switch, based on the measured magnitude.

Abstract: A control circuit of a power converter includes: an error detection circuit, configured to operably generate an error signal according to a reference signal and a feedback signal when coupling with an external feedback node of an external feedback circuit; an output signal detecting circuit, positioned inside the control circuit, configured to operably receive and detect an output signal of the power converter to generate a representative signal; an on time deciding circuit, coupled with the output signal detecting circuit, configured to operably generate an on time signal according to the representative signal; and a control signal generating circuit, coupled with the error detection circuit and the on time deciding circuit, configured to operably control on time of one or more power switches of the power converter according to the error signal and the on time signal.

Abstract: A system and method are provided for sensing current. A current source is configured to generate a current and a pulsed sense enable signal is generated. A sense voltage across a resistive sense mechanism is sampled according to the sense enable signal, where the sense voltage represents a measurement of the current. A system includes the current source and a current sensing unit. The current source is configured to generate a current. The current sensing unit is coupled the current source and is configured to generate a pulsed sense enable signal and sample the sense voltage across a resistive sense mechanism according to the pulsed sense enable signal.

Abstract: Disclosed herein are control apparatus, switching power supply, and control method embodiments for maintaining power conversion efficiency. An embodiment operates by determining whether or not a current of an inductor of the switching power supply has become less than or equal to a predetermined value, controlling a reference voltage based on at least one of a result of the determining or a result of comparing a voltage according to an output voltage of the switching power supply and the reference voltage, and pausing switching of the switching power supply based on the reference voltage.

Abstract: DC-DC converter PWM controllers and dual counter digital integrators are presented for integrating an error between a reference voltage signal and a feedback voltage signal, in which a comparator, dual counters, and a DAC are used to provide a compensated reference to a modulator loop comparator which generates a PWM switching signal for controlling a power converter output voltage, with the second counter being selectively incremented or decremented when the first counter output indicates a predetermined value after the first counter output transitions in one direction through a predetermined count range to enhance loop stability, and a startup mode control allows fast integrator operation during initialization, with the ability to freeze integrator operation during overcurrent conditions.

Abstract: In one embodiment, an integrated circuit (IC) includes a power distribution network having a first set of power distribution lines connected to a source voltage and a second set of power distribution lines connected to a ground voltage, and a first capacitor. A first variable resistive element is electrically coupled in series with the first capacitor between the first and second sets of power lines of the power distribution network. A control circuit is coupled to the variable resistive element and is configured and arranged to adjust a level of resistance of the first variable resistive element in response to an input signal. The adjustment of the level of resistance adjusts an equivalent series resistance of the power distribution network.

Abstract: An active diode formed within a buck power regulator with an NMOS transistor is connected to a PMOS transistor at a node that is further connected to the regulator output through an inductor. The active diode combines the NMOS transistor with circuitry to prevent conduction once the active diode passes a threshold voltage. Additional circuitry compares the output voltage to the target input voltage and varies the threshold voltage of the active diode such that the active diode can discharge excess current from the regulator each cycle until the output voltage is less than the target voltage.

Abstract: Hybrid buck converters that incorporate switching converter and auxiliary linear regulators are described. The auxiliary linear regulators are automatically activated during load transients to source or sink large currents to the output to achieve fast transient responses and are automatically deactivated during steady states to maintain high power efficiencies. With the proposed control scheme of automatic loop transition between linear and switching regulation loops, the power management interface design is simplified while the transient response performances are improved without compromising the power efficiencies.

Abstract: A DCDC converter includes a control circuit, a transistor in which switching is controlled by being supplied voltage output from the control circuit to a gate electrode of the transistor, a voltage conversion portion in which supply of input voltage is controlled by the switching of the transistor and output power commensurate with duty ratio of the switching of the transistor, and a detection circuit detecting the output power. Further, the control circuit includes a control signal generation circuit generating a control signal with a pulse voltage waveform and a selection circuit applying voltage of the control signal to the gate electrode in the case where current detected by the detection circuit is the same as or exceeds the threshold value and applying voltage for turning on the transistor to the gate electrode in the case where the current detected by the detection circuit falls below the threshold value.

Abstract: A level shift circuit and a DC-DC buck converter controller for using the same are disclosed. The level shift circuit is capable of detecting a state of a converting circuit, and avoids a current leakage when determining that the converting circuit is operating under a light-load. Therefore, the level shift circuit and the DC-DC converting controller provided by the present invention can reduce power consumption under the light-load and have power-saving advantage.

Abstract: In one aspect, a circuit includes a switching regulator configured to provide power to a load, a current regulator circuit coupled to the load and a response circuit configured to provide a control signal to the switching regulator in response to electrical changes of the current regulator circuit. The control signal changes non-linearly with respect to the electrical changes at the current regulator circuit. In another aspect, a circuit includes an adaptive regulation voltage circuit configured to provide a regulation voltage to a first input of an amplifier to maintain operability of a current regulator circuit. The adaptive regulation voltage circuit replicates electrical characteristics of the current regulator circuit.

Abstract: A controller with power saving for a power converter includes a delay circuit, a detection circuit, an output circuit, a counter circuit, a wake-up circuit and a PWM circuit. The delay circuit determines a delay time. The detection circuit activates the delay circuit whenever an output load of the power converter is lower than a light-load threshold. The output circuit generates a power-saving signal to cease a regulation of the power converter after the delay time ends. The regulation of the power converter is resumed once the output load increases during the regulation of the power converter is being ceased. The counter circuit coupled to the delay circuit is counted by the delay circuit to determine a sleep period. The output circuit generates the power-saving signal to cease the regulation of the power converter after the sleep period ends.

Abstract: A peak detector circuit receives an oscillating power supply signal. A capacitor is selectably coupled to the signal and charged to a value corresponding to a peak value of the signal. A switch is then opened to isolate the capacitor. When the signal rises to within a selected threshold, relative to the stored value, a comparator produces a command signal to close the switch, again coupling the capacitor to the signal. The peak detector can also include a tracking circuit that controls the capacitor to track the oscillating signal while the switch is closed, a timer circuit that closes the switch and activates the tracking circuit if more than a selected time passes without production of a command signal, a circuit that controls the polarity of a leakage current of the capacitor, a further auxiliary capacitor and a further auxiliary switch with a further control logic.

Abstract: A power supply system for maintaining the efficiency of an AC/DC power conversion unit in relation to a load is disclosed. The load varies in response to power usage during operation of the power supply system. An AC power input and a DC power output of the power conversion unit direct DC power to attached components. A master controller disposed in the power supply system detects the load of an attached computer system through a DC meter and executes an algorithm to determine the values of circuit parameters of conversion circuits in the AC/DC power conversion unit. The master controller sends the values to a mode controller through a digital signal interface. The mode controller adjusts the operating mode of the conversion circuits and thus changes the efficiency of the AC/DC power conversion unit.

Abstract: A voltage converter having a regulating circuit controlled by a duration adaptive pulse signal is disclosed. An input voltage is regulated by the regulating circuit according to the pulse signal to generate an output voltage. A first comparator of the voltage converter compares a first reference signal with a feedback value of the output voltage and thereby generates a first comparator output. The first reference signal fluctuates with the pulse signal. The voltage converter further includes an active-duration adjusting circuit that starts the active duration of the pulse signal in accordance with the first comparator output and ends the active duration of the pulse signal in accordance with a second reference signal. The DC value of the second reference signal depends on the duty cycle of the pulse signal.

Abstract: In one embodiment, a circuit comprises a sense circuit configured to sense an increase in an output voltage of a switching regulator under a light load condition. A pulse generating circuit generates a control signal to switch on and off a voltage input to the switching regulator. The pulse generating circuit reduces in a binary manner a switching frequency of the control signal under the light load condition as the sensed output voltage increases. As the output voltage rises, a clock signal is divided by two to remove every second pulse and applied to the pulse generating circuit. Further increases in the output voltage cause divisions of the clock frequency by four to remove 3 of 4 pulses so that only every fourth pulse remains. With output voltage increases, the frequency is divided by eight to remove 7 of 8 pulses so that every eighth pulse remains, and so forth.

Abstract: A driver circuit for a switched-mode power converter is configured to perform hysteretic control of a switched-mode power converter. The switched-mode power converter comprises an inductor configured to store energy during a first state of the switch and to release energy towards a load of the switched-mode power converter during a second state of the switch. The driver circuit comprises a filter unit which is configured to determine a command signal based on a gate control signal applied to a gate of the switch. The command signal is indicative of a current through the inductor. The driver circuit comprises hysteretic control circuitry configured to generate the gate control signal based on the command signal; wherein the switch alternates between the first and second state when being subjected to the gate control signal.

Abstract: A voltage converting controller. When output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value. After a period of time, the voltage converting controller sets the control frequency to a target control frequency corresponding to the second current value. And, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, the voltage converting controller sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A soft-start/soft-stop (SS) controller for a voltage regulator. The SS controller includes a power up/down detector configured to perform at least one selected from a group consisting of detecting a power on condition of the voltage regulator to determine a start-up time period and detecting a power off condition of the voltage regulator to determine a shut-down time period, and a ramped reference voltage signal generator configured to perform at least one selected from a group consisting of increasing a voltage level of a ramped reference voltage signal using a pre-determined ramp-up rate during the start-up time period and decreasing the voltage level of the ramped reference voltage signal using a pre-determined ramp-down rate during the shut-down time period, wherein the ramped reference voltage signal is supplied to the voltage regulator for controlling an output voltage level of the voltage regulator.

Abstract: A supply voltage regulation system for an IC including a temperature sensor that detects temperature of the IC, a scaling resistor coupled between a power grid and a feedback node of the IC, a regulator amplifier that compares a voltage of the feedback node with a reference voltage for developing a supply voltage for the IC, and a temperature scaling circuit that drives a scaling current to the scaling resistor via the feedback node to adjust the supply voltage based on temperature. The temperature scaling circuit may include one or more comparators that compare a temperature signal with corresponding temperature thresholds for selectively applying one or more bias currents to the scaling resistor. The scaling resistor may be coupled to a hot point of the power grid. A voltage difference between a hot point of a ground grid may be converted to a bias current applied to the scaling resistor.

Abstract: The invention relates to a self-oscillating pulse-width modulation amplifier in the form of a sine-cosine modulator (10) comprising at least two comparators (13, 14), two integrators (11, 12), a power switching stage (15), and negative feedback coupling with a low-frequency signal input and output. To achieve a maximum modulation factor, there are provisions with the aid of the comparators (13, 14) and integrators (11, 12) for the generation of sine- and cosine-square-wave voltages and sine- and co-sine-triangle-wave voltages that drive the power switching stage (15) in part, wherein the output of the power switching stage (15) combined with an LC low-pass filter (16) forms the low-frequency signal output. This brings about a situation in which a stable natural frequency exists and the modulation factor can be increased to nearly 100%.

Abstract: In one embodiment, a solar cell installation includes several groups of solar cells. Each group of solar cells has a local power point optimizer configured to control power generation of the group. The local power point optimizer may be configured to determine an optimum operating condition for a corresponding group of solar cells. The local power point optimizer may adjust the operating condition of the group to the optimum operating condition by modulating a transistor, such as by pulse width modulation, to electrically connect and disconnect the group from the installation. The local power point optimizer may be used in conjunction with a global maximum power point tracking module.

Abstract: A thermal balance conversion circuit includes a voltage conversion circuit, a temperature detection circuit, a PWM controller, and a signal integration controller. The voltage conversion circuit includes a plurality of voltage conversion units, and each of the voltage conversion units converts the DC voltage of a external power to a driving voltage. The temperature detection circuit includes a plurality of temperature detection units, and the plurality of temperature detection units detects temperatures of the plurality of voltage conversion units. The pulse width modulation controller outputs a plurality of different phase PWM signals according to each of the voltage conversion units. The signal integrated controller receives the PWM signals from the PWM controller to control the voltage conversion of each of the voltage conversion unit.

Abstract: An automatic adjusting device is provided, which is used for adjusting an output power of a power supply and comprises an automatic adjusting circuit. The automatic adjusting circuit includes a comparing unit and a programmable signal generating unit. The comparing unit compares a limiting level and a protection level and produces a comparison signal. The protection level limits the output power provided by the power supply. The programmable signal generating unit generates the protection level and adjusts the protection level according to the comparison signal for adjusting the output power. The programmable signal generating unit will adjust the protection level according to the limiting level. Thereby, the output power can be adjusted automatically without manual adjustment. Consequently, the cost can be reduced and the adjusting accuracy can enhanced.

Abstract: A switching power supply circuit is disclosed in an embodiment. The switching power supply circuit includes a power output stage, a pulse width modulation (PWM) signal generator, a compensation module, and a overshooting protection module. The power output stage is used for generating an output signal to drive a load device. The PWM signal generator generates a pulse width modulation (PWM) signal which is used for controlling the power output stage. The compensation module is used for generating a compensation signal to the PWM signal generator according to the output signal. The overshooting protection module receives the output signal to enable or disable the PWM signal generator.

Abstract: Methods and systems are disclosed that may be employed to improve efficiency of smart integrated power stages (IPstages) of multi-phase VR systems while operating under relatively light, ultra-light, or partial or reduced loads. The disclosed methods and systems may be implemented to improve VR system light load efficiency by providing and enabling reduced power IPstage operating modes in one or more smart IPstage/s of a VR system, and by enabling state transition between IPstage active and reduced power operating modes such as IPstage standby and IPstage hibernation modes.

Abstract: A DC-DC converter with improved voltage conversion efficiency is provided. The DC-DC converter includes a first circuit configured to generate a first signal containing data on current flowing through a load, a second circuit configured to amplify the first signal, a third circuit configured to generate a second signal containing data on voltage applied to the load, a fourth circuit configured to hold the second signal, a fifth circuit configured to amplify the second signal held by the fourth circuit, a sixth circuit configured to correct a difference in electrical characteristics between the second circuit and the fifth circuit, a seventh circuit configured to convert a first voltage to a second voltage supplied to the load, and an eighth circuit configured to control a level of the second voltage generated by the seventh circuit in accordance with either the amplified first signal or the amplified second signal.

Abstract: A control circuit, a time calculating unit, and operating method for control circuit are disclosed. The control circuit is operated in a power converter and coupled to a load. The control circuit includes an output stage and a time calculating unit. The time calculating unit receives a control signal and a reference voltage and provides a switch conducting signal to the output stage. The generation of the control signal is related to an output voltage of the power converter. When the difference between the control signal and the reference voltage becomes larger due to the change of the load, the time calculating unit dynamically increases an on-time of the switch conducting signal.

Abstract: An interleaved converter configured by connecting a plurality of switching converter circuits in parallel includes an inter-inductor switch that selects whether inductors are connected in series, an input side switch that is connected to a connection point of the inductor and the inter-inductor switch and selects whether electric power is supplied from a rectifier circuit to the inductor side, an output side switch that is connected to a connection point of the inductor and the inter-inductor switch and selects whether electric power is supplied from the inductor to the diode side, and a control circuit that controls the inter-inductor switch, the input side switch, and the output side switch.

Abstract: A control circuit for controlling a switching transistor and a synchronous rectifying transistor of a switching regulator includes: a bottom detection comparator configured to assert an on signal; an off signal generator configured to assert an off signal; a zero current detector configured to assert a zero current detection signal; and a control logic part configured to receive the on signal, the off signal and the zero current detection signal and generate a control signal such that the control circuit (i) transitions to a first state where, when the on signal is asserted, (ii) transitions to a second state where, when the off signal is asserted, and (iii) transitions to a third state where, when the zero current detection signal is asserted; In the third state, the control logic part reduces an operation current of at least a portion of the control circuit.

Abstract: A power source device includes: a transformer; a switching section driving a primary side of the transformer; and a controller capable of performing a switching operation on driving of the switching section for controlling an output of a secondary side of the transformer. The device detects a drive frequency for the switching section in the switching operation, and switches the drive frequency so as not to be a frequency in a prescribed range when the detected drive frequency reaches a threshold.

Abstract: A high-voltage heavy-current drive circuit applied in a power factor corrector, comprising a current mirroring circuit (1), a level shift circuit (3), a high-voltage pre-modulation circuit (2), a dead time control circuit (4) and a heavy-current output stage (5); the heavy-current output stage adopts a Darlington output stage structure to increase the maximum operating frequency of the drive circuit. The stabilized breakdown voltage characteristic of a voltage stabilizing diode is utilized to ensure the drive circuit operating within a safe voltage range. Adding dead time control into the level shift circuit not only prevents the momentary heavy-current from a power supply to the ground during the level conversion process, but also reduces the static power consumption of the drive circuit.

Abstract: A control apparatus for a switching device which suppresses surge voltages at the time of current shutoff of a switching device to protect from overcurrents although the switching device is not in an overcurrent state, including a current sensor, a comparator, a timer latch, a control circuit, and a transistor. The current sensor detects the current of a switching device and outputs a detected voltage. The comparator outputs a signal when the detected voltage is equal to or greater than a reference voltage. When the time duration of the output signal is equal to or greater than a setting time, the timer latch outputs a surge suppression detection signal, based on which the control circuit outputs to the transistor a driving signal to turn off the switching device. The reference voltage is smaller than a reference voltage used when detecting an overcurrent flowing in the switching device.

Abstract: The invention relates to a power control device for a power output stage. A forward signal corresponding to a wave advancing on a wall feed line and a return signal corresponding to a wave returning on the wave feed line is obtained by means of a directional coupler and is supplied to a controller after narrow-band selection for controlling the output of the power output stage. Narrow-band selection is not carried out in the baseband but on an intermediate frequency level above the baseband.

Abstract: The present invention includes: an ON-timer configured to control a period of time in which a main switching element is on; a voltage detecting circuit configured to detect an output voltage of a filter circuit; a triangular wave generator; a feed-forward circuit configured to generate a feed-forward output whose value decreases as a value of a DC voltage from a DC power supply increases; and a comparator configured to compare a second reference voltage generated by adding together a first reference voltage, a triangular wave signal from the triangular wave generator, and the feed-forward output from the feed-forward circuit, with the output voltage of the voltage detecting circuit, and based on a result of the comparison, output an ON-trigger signal for turning on the main switch element to the ON-timer.

Abstract: In one embodiment, a light-emitting diode (LED) driver can include: (i) a reference voltage control circuit configured to provide a reference voltage signal in response to an enable signal; (ii) a current control circuit configured to control an output current of the LED driver in response to the reference voltage signal; and (iii) the LED driver being configured to drive an LED load when the enable signal is active.