Abstract: A controller providing protection function and frequency-reduction function for a power conversion application, including: a voltage sense pin; a current source; a switch having a first end coupled to the current source, a second end coupled to the voltage sense pin, and a control end coupled with a control signal; and a sampling unit having a first node coupled to the voltage sense pin, a second node for providing the control signal, a third node for receiving a PWM signal, a fourth node for providing a first sampled voltage for a protection function, and a fifth node for providing a second sampled voltage for a frequency-reduction function.

Abstract: Disclosure includes control methods and power controllers with load compensation adapted for a power supply powering a load. A disclosed power controller comprises a converter and a control circuit. The converter converts the load signal at a first node to output a load-compensation signal at a second node. The load signal corresponds to an output power provided from the power supply to the load, and the converter includes a low-pass filter coupled between the first and second nodes. The control circuit is coupled to an inductive device via a feedback node, for controlling the output power to make a cross voltage of the inductive device approach a target voltage, based on a feedback voltage at the feedback node. The higher the load-compensation signal the higher the target voltage.

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: The present invention discloses CVCC circuits and methods with improved load regulation for an SMPS. In one embodiment, the CVCC can include: a voltage feedback circuit to generate an output voltage feedback signal; a current feedback circuit to generate an output current feedback signal; a control signal generating circuit that receives the output voltage feedback signal and the output current feedback signal, and generates a constant voltage/constant current control signal; a first enable signal generating circuit that compares a first reference voltage and the constant voltage/constant current control signal to generate a first enable signal; and a PWM controller that generates a PWM control signal based on the constant voltage/constant current control signal to control a main switch of the flyback SMPS.

Abstract: A control circuit for use in a power converter includes a drive signal generator coupled to generate a drive signal to control switching of a switch to regulate an output of the power converter. An event detection circuit is coupled to the drive signal generator to indicate if a switching period of one switching cycle of the drive signal exceeds a threshold switching period. An event counter circuit is coupled to the event detection circuit to render dormant the drive signal generator if the event detection circuit indicates a period of a switching cycle of the drive signal exceeds the threshold switching period for a threshold consecutive number of switching cycles.

Abstract: Embodiments of the invention provide a method and a circuit for generating a reference signal for controlling a peak current of a converter switch. According to at least one embodiment, a dead-zone generator configured to form a dead-zone in an input voltage signal divided from a primary-side supply voltage of an isolated converter, and a duty ratio calculator configured to calculate a duty ratio of energy transfer to a secondary side. The circuit further includes an operator configured to generate and output a reference signal for controlling the peak current of the converter switch from a dead-zone voltage signal having the dead-zone using the duty ratio of energy transfer calculated by the duty ratio calculator.

Abstract: Embodiments of the invention provide a method and a circuit for generating a reference signal for controlling a peak current of a converter switch. According to at least one embodiment, the circuit includes a squarer configured to squire an input voltage signal divided from a primary-side supply voltage of an isolated converter, and a duty ratio calculator configured to calculate a duty ratio of energy transfer to a secondary side. The circuit further includes an operator configured to generate and output a reference signal for controlling the peak current of the converter switch from a square signal of the input voltage signal using the duty ratio of energy transfer calculated by the duty ratio calculator.

Abstract: System and method for regulating a power converter. The system includes a first signal generator configured to receive at least an input signal and generate at least a first output signal associated with demagnetization and a second output signal associated with sampling. Additionally, the system includes a sampling component configured to receive at least the input signal and the second output signal, sample the input signal based on at least information associated with the second output signal, and generate at least a third output signal associated with one or more sampled magnitudes. Moreover, the system includes an error amplifier configured to receive at least the third output signal and a first threshold voltage and generate at least a fourth output signal with a capacitor, the capacitor being coupled to the error amplifier.

Abstract: System and method for regulating a power converter. The system includes a first comparator configured to receive a first input signal and a second input signal and generate a first comparison signal based on at least information associated with the first input signal and the second input signal, a pulse-width-modulation generator configured to receive at least the first comparison signal and generate a modulation signal based on at least information associated with the first comparison signal, a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter, and a voltage-change-rate detection component configured to sample the feedback signal to generate a first sampled signal for a first modulation period and to sample the feedback signal to generate a second sampled signal for a second modulation period.

Abstract: A controller of a switching power converter sets an actual turn-on time of a switch in the switching power converter in each switching cycle by selecting one of a plurality of valley points of the output voltage of the switching power converter occurring subsequent to the desired turn-on time of the switch. The desired turn-on time of the switch may be calculated according to the regulation scheme employed by the switching power converter. The controller selects one of the plurality of valley points randomly from switching cycle to switching cycle. The controller generates a control signal to turn on the switching power converter at the selected one of the plurality of valley points of the output voltage occurring subsequent to the desired turn-on time.

Abstract: An active voltage drop control-type pulse power generator includes power stages, a power inverter, a power loop, a control inverter, a control loop, and a compensation unit. The power stages include power cells connected in series. Each power cell includes a switch and a capacitor connected in series, a driver for driving the switch, a bypass diode connected to both ends of the switch, and a rectifying diode connected to both ends of the capacitor. The power inverter charges the capacitor via the power loop and the rectifying diode inside each power cell. The control inverter provides a control signal for the switch via the control loop and the driver inside each power cell. The compensation unit is connected to one of the power cells and generates a compensation voltage for compensating for a voltage drop at a load according to a voltage detected in real-time from the power cell.

Abstract: According to one embodiment, a power supply device includes a substrate, a first inductor, and a second inductor. The substrate has a first surface and a second surface on opposite side from the first surface. The first inductor includes a first coil having a coil center axis substantially parallel to a first direction, is used for a switching circuit for controlling power supplied to a load, and is mounted on the first surface of the substrate. The second inductor includes a second coil having a coil center axis substantially parallel to the first direction, is electrically connected to the first inductor, and is mounted on the second surface of the substrate. As viewed in a direction orthogonal to the first surface, position of the first coil of the first inductor does not overlap position of the second coil of the second inductor.

Abstract: A switching mode power supply, having: a power switch; an energy storage component coupled to the power switch; a current sense resistor configured to generate a current sense signal; a mode select resistor configured to generate a mode select resistor; a ZCD (Zero Cross Detecting) circuit configured to generate a ZCD signal; and a control circuit configured to provide a switch control signal to control the on and off of the power switch, the control circuit having a multi-function pin configured to receive the mode select signal, the current sense signal and the ZCD signal.

Abstract: A primary side regulator according to an embodiment includes a power switch connected to a primary winding, a secondary winding configured to be insulated and coupled to the primary winding, a diode connected between the secondary winding and an output terminal, and an auxiliary winding coupled to the primary winding, and insulated and coupled to the secondary winding. The primary side regulator controls a switching operation of the power switch using a voltage obtained by filtering at least one of an estimation voltage signal corresponding to an output voltage of the output terminal and an estimation current signal corresponding to an output current flowing through the diode.

Abstract: Systems and methods are provided for signal processing. An example error amplifier for processing a reference signal and an input signal associated with a current of a power conversion system includes a first operational amplifier, a second operational amplifier, a first transistor, a second transistor, a current mirror component, a switch, a first resistor and a second resistor. The first operational amplifier includes a first input terminal, a second input terminal and a first output terminal, the first input terminal being configured to receive a reference signal. The first transistor includes a first transistor terminal, a second transistor terminal and a third transistor terminal, the first transistor terminal being configured to receive a first amplified signal from the first output terminal, the third transistor terminal being coupled to the second input terminal.

Abstract: An example control circuit for use in a power converter includes an input voltage sensor, a current sensor, and a drive signal generator. The input voltage sensor generates a first signal representative of an input voltage (Vin) of the power converter. The current sensor generates a second signal representative of a switch current through a power switch of the power converter. The drive signal generator generates a drive signal to control switching of the power switch in response to the first and second signals. The drive signal generator adjusts a duty cycle of the drive signal based on a product K×Vin×t to control a maximum output power of the power converter, where K is a fixed number and t is a time it takes the second signal to change between two values of the switch current when the power switch is in an on state.

Abstract: A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.

Abstract: This relates to sampling a feedback signal representative of an output of a power converter. The sampling is performed using a buffer sampling circuit having three sample and hold stages coupled in series to sense and store the feedback signal. The first stage is coupled to sample and hold the feedback signal on a capacitor. If the output diode is conducting, the sampled signal is transferred to the second stage. If the output diode is conducting, the first stage will sample the feedback signal and the sampled signal will be transferred to be sampled and held by the second stage. When the output diode stops conducting, the sampled voltage held by the second stage is transferred to the third stage. The third stage stores the sampled voltage on a capacitor. As such, the controller may sample the feedback signal near the end of the output diode conduction time.

Abstract: System and method for regulating a power converter. A system for regulating a power converter includes a controller, a first switch, and a second switch. The controller is configured to generate a first switching signal and a second switching signal. The first switch is configured to receive the first switching signal, the first switch being coupled to an auxiliary winding of the power converter further including a primary winding and a secondary winding. The second switch is configured to receive the second switching signal and coupled to the primary winding of the power converter. The controller is further configured to, change, at a first time, the second switching signal to open the second switch, maintain, from the first time to a second time, the first switching signal to keep the first switch open, and change, at the second time, the first switching signal to close the first switch.

Abstract: A switch-mode power supply (SMPS) includes a transformer having a primary winding coupled to a power switch, a secondary winding for providing an output of the power supply, and a controller. The controller includes a first input terminal for receiving a current sensing signal related to a current in the primary winding, a second input terminal for receiving a feedback signal related to a current in the secondary winding, and an output terminal for providing a control signal to turn on and off the power switch. When the feedback signal is higher than a first reference voltage, the controller is configured to cause the SMPS to maintain a constant output current at a first current magnitude. When the feedback signal is lower than the first reference voltage, the controller is configured to cause the SMPS to provide a second output current at a second current magnitude higher than the first current magnitude.

Abstract: A switching power converter provides regulated output power to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage, a secondary winding coupled to an output of the switching power converter, an auxiliary winding on a primary side of the transformer, and a switch coupled to the primary winding of the transformer. Output voltage across the secondary winding is reflected as a feedback voltage across the auxiliary winding. The switching power converter detects output current based on a reset time of the transformer. Based on the detected output power, the switching power converter controls switching of the switch to provide regulated output power.

Abstract: The present disclosure relates to an LC snubber circuit for a switching converter, wherein the switching converter includes an inductor and a switching device connected in series. The LC snubber circuit can include a first snubber diode, a snubber capacitor, a second snubber diode, and a snubber transformer having a primary winding and a secondary winding. The secondary winding of the snubber transformer is connected to an output of the switching converter.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a first primary winding coupled to an input voltage, a second primary winding, a secondary winding coupled to an output of the switching power converter, and an auxiliary winding, a first switch coupled to the first primary winding, and a second switch coupled to the secondary primary winding. A controller generates a first control signal to turn the first switch on or off at a first switching frequency, and a second control signal to turn the second switch on or off at a second switching frequency that is higher than the first frequency. During off cycles of the switches, feedback voltage representing the output voltage of the power converter is generated across the auxiliary winding. The controller controls switching of the first switch to regulate the output voltage based on the feedback.

Abstract: A control circuit of the power converter according to the present invention comprises a feedback circuit, an output circuit and an adaptive clamping circuit. The feedback circuit generates a feedback signal in accordance with an output of the power converter. The output circuit generates a switching signal in accordance with the feedback signal for regulating the output of the power converter. The adaptive clamping circuit limits the level of the feedback signal under a first level for a first load condition. The feedback circuit determines a slew rate of the feedback signal for increasing the level of the feedback signal from the first level to a second level. The adaptive clamping circuit is disabled and the level of the feedback signal can be increased to the second level for a second load condition.

Abstract: The present application provides a control device for controlling a switching converting module to generate an output signal of constant output current from a rectified AC power supply signal. The switching converting module comprises a primary winding for receiving the rectified AC power supply signal and a power switch coupled in series with the primary winding.

Abstract: A switching power-supply device includes a COMP-voltage comparator circuit that compares a COMP-voltage obtained by performing phase compensation on the feedback signal, with a first threshold voltage which is a threshold value; and an intermittent-oscillation control circuit that, if it is detected by the COMP-voltage comparator circuit that the COMP-voltage is lower than the first threshold voltage, stops the switching operation of the switching device and performs a transition to a first intermittent oscillation operation in which the switching device performs the switching operation every predetermined first period, wherein if a predetermined delay period elapses in a state where the COMP-voltage is lower than the first threshold voltage, the intermittent-oscillation control circuit performs a transition to a second intermittent oscillation operation in which the switching device performs the switching operation every second period which is an integral multiple of the first period.

Abstract: A switching regulator related to aspects of the invention can include an auxiliary winding for monitoring the voltage across the primary winding of a transformer, a differentiation detecting circuit that detects the timing of reversal start or reversal end of the signal detected by the auxiliary winding and a dead time adjusting circuit that receives a signal to trigger turn OFF of a first switch or a second switch and, after passing a predetermined delay time from the detection of the signal, generates a signal to trigger turn ON of the first switch or the second switch. The differentiation detecting circuit can confirm current transfer between body diodes. The dead time adjusting circuit can adjust a dead time to deliver the signal after a predetermined time from the confirmation of the current transfer. In some aspects of the invention, occurrence of hard switching and short-circuit current can be suppressed.

Abstract: A secondary-side dynamic load detection system and method rapidly identifies when a dynamic load has been placed on the output (e.g., when an electronic device is re-connected to the switching power converter). Once a dynamic load condition has been detected by the secondary side detector, a dynamic load detection signal is communicated from the secondary side of the switching power converter to a switch controller on the primary side. The switch controller can then quickly adapt switching in response to the dynamic load condition.

Abstract: A pulse frequency modulation (PFM) controller for controlling a switching mode power supply. The controller includes an output terminal for providing a control signal to turn on and off a current in the power supply to regulate an output of the power supply. A first input terminal receives a feedback signal related to the output of the power supply, the feedback signal exhibiting a ringing waveform when the current in the power supply is turned off. The controller also includes a control circuit configured to provide the control signal in response to the feedback signal. The control signal is adapted to turn on the current in the power supply when the feedback signal is substantially at a valley of the ringing waveform of the feedback signal. In an embodiment, such a PFM controller can reduce turn-on transition loss in a power supply and provides frequency dithering to reduce electromagnetic interference.

Abstract: System and method for regulating a power converter. The system includes a comparator configured to receive a first signal and a second signal and generate a comparison signal based on at least information associated with the first signal and the second signal. The first signal is associated with at least an output current of a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive at least the comparison signal and generate a modulation signal based on at least information associated with the comparison signal, and a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter. The modulation signal is associated with a modulation frequency corresponding to a modulation period.

Abstract: A flyback converter with primary side and secondary side feedback control includes a transformer, a secondary-side feedback unit and a feedback control unit. The secondary-side feedback unit is electrically connected to a secondary winding of the transformer and comprises an isolated signal transceiver device and an error amplifier. The feedback control unit is electrically connected to an auxiliary winding of the transformer and operatively connected to the isolated signal transceiver device. When the flyback converter is operated in heavy load conditions, the feedback control unit receives a secondary feedback control signal sent from the isolated signal transceiver device for feedback control. When the flyback converter is operated in light load conditions, the feedback control unit receives a primary feedback control signal sensed by the auxiliary winding for feedback control.

Abstract: A switching power supply device and method for control thereof, including an input voltage generating unit, a transformer, an output voltage generating unit, a MOS transistor, an output voltage detecting unit, a switching control unit, and a power supply unit. The output voltage detecting unit detects a transformer tertiary winding voltage, compares it with a first reference value, compares the differentiated tertiary winding voltage with a second reference value, and determines the start and end of a detection period based on the two comparisons. The output voltage detecting unit also samples and holds the voltage with two sampling pulses within the detection period, selects one of the two sampled and held voltages, and outputs the selected voltage when the detection period ends.

Abstract: A power supply circuit includes a plurality of output terminals that output voltages (voltages may have the same or different voltage values among the output terminals), and a transformer that has a plurality of output windings. First and second output windings of the plurality of output windings are coupled to each other. The first and second output windings have the same number of turns. First terminals, which have a first polarity, of the first and second output windings are connected to each other via a capacitor. Further, second terminals, which have a second polarity opposite to the first polarity, of the first and second output windings are electrically connected to each other. The second terminals of the first and second output windings may be directly connected to each other.

Abstract: Provided are a power supply device and a method of controlling the same. The power supply device includes: a power factor corrector which corrects a power factor of an initial power; a standby power supply unit which is connected to the power factor corrector, the standby power supply unit including a transformer which converts an input power received from the power factor corrector; a sensor which detects a level of an induced power corresponding to the input power; and a power supply controller which determines whether the level of the induced power exceeds a critical value, activates the power factor corrector to correct the power factor of the initial power if the level of the induced power exceeds the critical value, and supplies a driving power to the system based on the level of the induced power.

Abstract: In one embodiment, a method of controlling a capacitor discharge for a switching power supply, can include: (i) generating a first voltage signal from a voltage at an X capacitor that is coupled between input terminals of the switching power supply; (ii) activating a detection signal in response to the first voltage signal being inactive for a duration of a predetermined time interval, where the detection signal being activated indicates a cut-off of the input terminals; and (iii) at least partially discharging the X capacitor after the cut-off and in response to activation of the detection signal.

Abstract: A switching power converter provides a communication link between a secondary side and a primary side of the switching power converter. During a messaging mode, the communication link enables information to be transmitted from an electronic device coupled to the secondary side to a controller on the primary side. The communication link may be used to transmit operating parameters related to powering the electronic device. The switching power converter may then adapt its switching operation to achieve different regulated output voltage and/or current to accommodate the detected electronic device.

Abstract: Driver circuits comprise power converters detecting automatically a topology used by the driver circuits. A controller controls a plurality of different types of power converters in accordance to a corresponding plurality of different operation modes. The controller comprises a measurement pin coupled to a first topology resistor of a first power converter of a type from the plurality of different types. The different types of power converters comprise topology resistors of corresponding different resistor values. The controller senses a voltage at the measurement pin wherein the voltage at the measurement pin is indicative of a voltage drop at the first topology resistor. Furthermore, the controller determines a type of the first power converter based on the sensed voltage, and selects an operation mode for controlling the first power converter.

Abstract: A controller having an on-time controller, an off-time controller, a switch control signal generator, and a jittering signal generator, wherein the jittering signal generator couples jitter into the on-time or the off-time of a primary switch of the power supply. Therefore the EMI performance may be improved.

Abstract: Disclosed is a compact inverter plug that can be used with LED lighting strings. The converter plug has a size and shape that is comparable to a standard wall plug and is capable of plugging into a standard wall socket. The converter plug is waterproof and can be easily assembled. A unique converter circuit is utilized that is compact and highly efficient. Monitoring is performed by a transformer coil that generates a monitoring signal. The converter is controlled by controlling the modulation frequency of a direct current signal using a controller.

Abstract: A power distribution system and method includes a controller that is configured to control a switching power converter. In at least one embodiment, the controller includes a compensation current control circuit to control a compensation current that reduces and, in at least one embodiment, approximately eliminates variations in current drawn by the controller during a particular operational time period. In at least one embodiment, the power distribution system is a lamp that includes the controller, a switching power converter, and one or more light sources, such as light emitting diodes.

Abstract: The power supply apparatus includes a first control part that controls a switching operation of a first converter, a second control part that controls a switching operation of a second converter, a zero crossing circuit that outputs a zero crossing signal of a voltage to be input; and a voltage supply part that supplies a DC voltage obtained by rectifying an output of an auxiliary coil of a transformer of the first converter to the first control part, the second control part, and the zero crossing circuit. When the first converter stops, the supply of the DC voltage to the second control part and the zero crossing circuit is stopped to reduce a power consumption.

Abstract: A controller includes a control, a sensor, and a fault detector. The control is configured to control a switch to regulate an output of the power converter. The sensor receives a signal from a terminal of the controller that is representative of an input voltage during an ON state of the switch and is representative of an output voltage during an OFF state of the switch. The sensor is configured to sample the signal from the terminal during the ON state to generate a first sample signal and to sample the signal from the terminal during the OFF state to generate a second sample signal. The fault detector detects a fault condition in response to either the first or the second sample signals. The control inhibits the switching of the switch to reduce a power output level of the power converter in response to the fault condition.

Abstract: Techniques are disclosed for providing a stable output voltage in switching mode power supplies (SMPS). An SMPS includes a switching converter for powering a load, a passive startup circuit for initially providing an internal voltage supply for powering switching electronics when the mains is turned on, and a feedback circuit providing the internal voltage supply once the switching converter starts switching. The SMPS also includes a decoupling circuit that decouples or otherwise isolates the gain of the passive startup circuit from the feedback circuit, so as to prevent false dynamic overvoltage protection triggers. The decoupling circuit is implemented, for instance, with the addition of two or three passive components, such as a diode and a capacitor, or a diode, a capacitor, and a resistor. Preventing false triggering of the dynamic overvoltage protection in turn provides a more stable output voltage from the SMPS.

Abstract: An apparatus and method for a flyback power converter reduce the standby output voltage of the flyback power converter by switching the reference voltage provided by a shunt regulator of the flyback power converter or the ratio of voltage divider resistors of the shunt regulator, to reduce the standby power consumption by an output feedback circuit of the flyback power converter, the shunt regulator, and the voltage divider resistors, and thereby improve the power loss of the flyback power converter in standby mode.

Abstract: A power converter control circuit includes a ramp signal circuit, a blanking circuit, and a pulse driver circuit. The ramp signal circuit provides a ramp signal in response to a power converter feedback signal and an enable signal. The blanking circuit provides a blanking signal in response to the ramp signal and a clock signal. The blanking signal is provided when both the ramp signal is increasing in value and the enable signal indicates a light load operating condition. The pulse driver circuit provides a power switch control pulse in accordance with the clock signal and in the absence of the blanking signal.

Abstract: A switching power converter (200, 300, 400, 500) comprises a transformer (211) with a parasitic capacitance (212), a first switch (207) coupled to the transformer (211) and configured to couple or decouple a load (219) to or from a power source via the transformer (211), a switch controller (205) coupled to the first switch (207) and configured to generate a switch drive signal (206) for turning on or off the first switch (207) according to switching cycles, and a bypass circuit configured to provide a bypass path for the parasitic elements such as the parasitic capacitance (212). The bypass circuit may be coupled in parallel with the auxiliary winding (220), the primary winding (213), or the secondary winding (214) of the transformer (211). High frequency ringing and EMI/RFI is reduced when the bypass circuit is enabled.

Abstract: A sensing arrangement and method a sense winding is used to provide a voltage which represents the voltage appearing across an in-circuit magnetic component. In a flyback phase, when the component is supplying the output, that voltage represents an output voltage and in a supply phase, the supply voltage. This arrangement provides a solution to the problem of the disparity in magnitude of sense winding output during the two phases by proving a pull-up resistor arranged to apply bias to the voltage measured, the pull-up being to a first level during the supply period and to a second value during the flyback period, the first and second levels being selected such that the voltage across the sense winding is scaled differently during the supply period and the flyback period. The invention is suitable for use in a transformer based flyback power converter in which the magnitude disparity problem may be exacerbated by a turns ratio.

Abstract: The present invention is a switching power source device which converts AC power of an AC power source into DC power and outputs the DC power, the device including: a rectifying-smoothing circuit configured to output a rectified-smoothed voltage signal obtained by rectifying and smoothing an AC voltage of the AC power source; a transformer having a primary winding, a secondary winding, and an auxiliary winding; a switching element connected to the primary winding of the transformer; and a control circuit configured to turn the switching element on and off based on a voltage signal which is based on an average value of current flowing through the switching element and the rectified-smoothed voltage signal from the rectifying-smoothing circuit.

Abstract: An example power supply controller includes a signal separator circuit that generates a feedback signal. An error signal generator generates an error signal in response to the feedback signal. A control circuit generates a drive signal in response to the error signal. The drive signal controls switching of a switch. A multi-cycle modulation circuit is included in the control circuit and generates a skip signal in response to a start skip signal, a stop skip signal and a skip mask signal. The skip mask signal is generated in response to the skip signal. The start skip and stop skip signals cause the drive signal to start skipping or stop skipping, respectively, on-time intervals of cycles. The skip mask signal disables the start skip signal from causing the drive signal to start skipping the on-time intervals of cycles.

Abstract: There is provided a power supply device including: a first controller operating a pulse width modulation (PWM) control integrated circuit (IC) when a load is connected to an output terminal thereof; a second controller determining whether to operate the PWM control IC according to a change in voltage of an auxiliary capacitor connected to the first controller when a load is not connected to the output terminal; and a constant voltage circuit unit supplying a constant voltage to the first controller and the second controller when the PWM control IC operates. Power consumption can be considerably reduced when a load is not connected to the output terminal of the power supply device. Also, since elements for controlling the power supply device are implemented as a single integrated circuit (IC), a leakage current can be reduced to thus minimize power consumption. In addition, voltage can be supplied to the IC while reducing switching noise.