Abstract: A control circuit and a control method of a switching power supply, according to feedback signals on a pin FB and a pin CS, a constant current control module generates and outputs a control signal to control an output current of the switching power supply, thereby regulating duty cycle of a first transistor adaptively and controlling an output current Io of a power supply system to be constant; according to the feedback signals on the pin FB and on the pin CS, a constant current precision compensation module adaptively regulates circuit parameters of the constant current control module and a sample-and-hold module, preventing precision of constant current output from being influenced by change of a working mode and/or by variation of input conditions; when an output voltage changes, QR mode keeps unchanged or depth of a CCM keeps approximately constant.

Abstract: Thermoelectric energy harvesting systems in accordance with embodiments of the invention enable energy harvesting. One embodiment includes a thermoelectric energy harvesting (TEH) system comprising a TEH comprising a thin-film array-based TEH source; start-up mode circuitry comprising: an upper branch comprising: a mode switch configured to allow selection of the upper branch; an inductive-load ring oscillator (ILRO); a charge pump configured to receive an input from the ILRO and output current, where output current is utilized to charge an upper branch capacitor; a lower branch comprising: an inductor; an active diode configured to transfer energy stored in the inductor to an output capacitor; maximum-power-point tracking (MPPT) mode circuitry, where the MPPT loop comprises: a mode control unit; a gate controller; a clock generator configured to generate at least one control signal; an analog-domain MPPT unit configured to receive the at least one generated control signal.

Abstract: An isolated power transfer device has a primary side and a secondary side isolated from the primary side by an isolation barrier. A secondary-side circuit includes a rectifier circuit coupled to a secondary-side conductive coil. The secondary-side circuit includes a first resistor coupled to a first power supply node and a terminal node. The secondary-side circuit includes a second resistor coupled to the terminal node and a second power supply node. The secondary-side circuit includes a first circuit to generate a feedback signal in response to a reference voltage and a signal on the terminal node. The feedback signal has a hysteretic band defined by the first resistor and the second resistor. The secondary-side circuit is configured as an AC/DC power converter that provides, on the first power supply node, an output DC signal having a voltage level based on a ratio of the first resistor to the second resistor.

Abstract: Signal transmission circuitry comprises a conductive transmitting coil, a first power supply, a semiconductor switch to reversibly couple the transmitting coil to the first power supply, control circuitry to control the coupling of the transmitting coil to the first power supply by the semiconductor switch, a second power supply coupled to supply power to the control circuitry.

Abstract: A drive includes an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus. A power factor correction (PFC) circuit outputs power to the DC voltage bus based on input alternating current (AC) power. The PFC circuit includes: (i) a switch having a first terminal, a second terminal, and a control terminal; (ii) a driver that switches the switch between open and closed states based on a control signal; (iii) an inductor that charges and discharges based on switching of the switch; and (iv) a circuit that outputs a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch.

Abstract: A flyback power converter includes a transformer having a primary winding receiving an input power, a secondary winding generating an output power, and an auxiliary winding generating an auxiliary voltage and providing a supply voltage, a primary side switch controlling the primary winding, a start-up switch coupled to the input voltage and the supply voltage, and a primary side controller supplied by the supply voltage. The primary side controller includes a shared pin coupled to a control terminal of the start-up switch, a start-up circuit for controlling the start-up switch to be conductive through the shared pin when the supply voltage is lower than a threshold, and a signal processing circuit receiving an auxiliary signal related to the auxiliary voltage through the shared pin and operating the flyback power converter accordingly, wherein the shared pin, besides providing a function of controlling the start-up switch, provides another function.

Abstract: Methods and circuits for controlling a synchronous rectifier. An operating condition of the synchronous rectifier is detected. A voltage level applied to turn on at least one transistor of the synchronous rectifier us modified based upon the detected operating condition, to improve efficiency of the synchronous rectifier.

Abstract: A semiconductor device for power supply control includes an on/off control signal generation circuit which generates a control signal to turn on or off the switching element, a high-voltage input start terminal to which alternating-current voltage of AC input or voltage rectified in a diode bridge is input, a high-voltage input monitoring circuit connected to the high-voltage input start terminal and monitoring voltage of the high-voltage input start terminal, and a discharging unit connected between the high-voltage input start terminal and a ground point. When the high-voltage input monitoring circuit detects that a time for which the voltage of the high-voltage input start terminal is not lower than a predetermined voltage value for a predetermined period, the discharging unit is turned on.

Abstract: An isolated DC/DC converter includes a transformer having a first winding and a secondary winding, a switching transistor connected to the primary winding of the transformer, a rectifier element connected to the secondary winding of the transformer, a photocoupler, a feedback circuit configured to drive a light emitting element on an input side of the photocoupler by a forward current corresponding to an error between an output voltage of the DC/DC converter and a target voltage of the DC/DC converter, a conversion circuit configured to convert a collector current flowing in a light receiving element on an output side of the photocoupler into a feedback voltage having a negative correlation with the collector current, a pulse signal generator configured to generate a pulse signal corresponding to the feedback voltage, and a driver configured to drive the switching transistor depending on the pulse signal.

Abstract: Aspects include a hold-up capacitor charging circuit for a power supply. The hold-up capacitor charging circuit includes a voltage boosting charge pump circuit with a hold-up capacitor electrically coupled to a voltage source. The hold-up capacitor charging circuit also includes a fly-back circuit. The fly-back circuit includes a transformer with a primary winding electrically coupled to the voltage source and a secondary winding electrically coupled to a load. A switch is electrically coupled to the primary winding and the voltage boosting charge pump circuit. A controller is operable to open and close the switch to control energy transfer from the primary winding to the secondary winding and charge the hold-up capacitor responsive to voltages of the voltage source, the voltage boosting charge pump circuit, and a reflected voltage of the secondary winding at the primary winding.

Abstract: An ionization detector that reduces the filtering effects of the ignition coil inductances by shorting an inductance of a primary winding of the ignition coil. The ionization detector includes a bias voltage source and an inductance control switch. The bias voltage source supplies electric voltage across an electric gap of a spark plug for detecting ionization within the combustion chamber. The inductance control switch is electrically parallel with a primary winding of an ignition coil and is operable to short an inductance of the primary winding.

Abstract: A power inverter includes a plurality of bridge arms and a plurality of switching circuits. The bridge arms are electrically coupled to a first and a second dc node and a neutral point node, and respectively coupled to a corresponding one of a plurality of ac output nodes to provide an ac output voltage and output current via the ac output node. The switching circuits are respectively coupled between a corresponding one of the ac output nodes and the neutral point node. Each of the switching circuits includes a first transistor, a second transistor, a first diode and a second diode. The first and the second transistors are coupled in series to each other. The first and the second diodes are electrically coupled in inverse-parallel to the first and the second transistors respectively.

Abstract: A DC-DC power converter includes an input, an output, a transformer, and a primary FET coupled to selectively conduct current though a primary winding of the transformer. The primary FET includes a drain that experiences multiple resonant voltage valleys during each dead-time period of the converter. The converter further includes a synchronous rectifier coupled to selectively conduct current through a secondary winding of the transformer, and a control circuit. The control circuit is configured to operate the primary FET in a valley skipping mode by turning on the primary FET during a second or subsequent one of the multiple resonant voltage valleys, and to allow a negative current in the secondary winding of the transformer before turning off the synchronous rectifier during one or more of the multiple resonant voltage valleys. Methods of operating DC-DC power converters are also disclosed.

Abstract: An apparatus including a first circuit and a second circuit. The first circuit may generate an output signal with a regulated voltage and maintain a constant switch frequency having a first on time and a first off time. The second circuit may generate a shifted signal based on a phase delay with respect to the output signal and maintain a shifted frequency having a second on time and a second off time. The second on time may follow the first on time by the phase delay. The second on time may be based on the first on time and transient conditions of a load. The apparatus may implement an automatic phase shift adjustment. A current sensing comparison may implement a cycle-by-cycle comparison between the output signal and the shifted signal to determine the second on time and perform a tuning operation to achieve inductor current balancing.

Abstract: Disclosed are AC-DC voltage converter circuits and methods for low standby power consumption. In one embodiment, a method can include: (i) detecting operating states of an input power supply, where the input power supply is received by a safety capacitor and provided to a switching power supply circuit after being rectified and filtered; (ii) removing a phantom load when the input power supply operates in a normal operating state; (iii) loading the phantom load when the input power supply operates in an under voltage lock out state; and (iv) when the input power supply operates in the under voltage lock out state, using energy stored in the safety capacitor to supply power to a load of the switching power supply circuit and the phantom load, and disabling a power stage circuit until a voltage of the safety capacitor is reduced to less than a safety threshold value.

Abstract: A PWM controller in a switching mode power supply provides to a power switch a PWM signal determining an ON time and an OFF time. A peak detector detects a voltage peak of a line voltage generated by rectifying an alternating-current input voltage. An OFF-time control unit controls the PWM signal and determines the OFF time in response to a compensation voltage, which is in response to an output voltage of the switching mode power supply. An ON-time control unit controls the PWM signal and determines the ON time in response to the compensation voltage and the voltage peak. The ON-time control unit is configured to make the ON time not less than a minimum ON time, and the minimum ON time is determined in response to the voltage peak.

Abstract: Systems, methods, and apparatus for a circuit with adaptive switching frequency control are disclosed. The method comprises operating a controller of the dimmable single-stage power converter in pulse width modulation (PWM) mode at a first switching frequency level from a maximum dimming duty-ratio level until a first dimming duty-ratio level. The method further comprises operating the controller in PWM mode, while reducing switching frequency from the first switching frequency level to a second switching frequency level, from the first dimming duty-ratio level until a second dimming duty-ratio level. Also, the method comprises operating the controller in PWM mode at the second switching frequency level from the second dimming duty-ratio level until a current command (Vipk) falls below a predetermined low limit value. Further, the method comprises operating the controller in skip mode, while reducing the switching frequency from the second switching frequency level, until a minimum dimming duty-ratio level.

Abstract: Disclosed is a method of acquiring input and output voltage information by employing a pulse width modulation (PWM) controller, which is in collocation with an input power processing unit, a primary inductor, a switch element, a current-sensing resistor, an output rectifier, and an output filter for converting an alternating current input power into an rectified input power and an output power, and the output power supplies an external load. A current-sensing signal is specifically disposed and applied to calculation of the input voltage and output voltage of the rectified input power when the switch element is turned on and off, respectively. Thus, no resistive voltage divider is needed, and power consumption at no load is greatly improved.

Abstract: System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

Abstract: An LED power supply device includes a primary winding, a secondary winding, a charge-pump capacitor, a bridge rectifier circuit, a unidirectional controlled switch, and an output capacitor. The secondary winding includes a first terminal and a second terminal and configured to provide a secondary current in response to a primary current flowing through the primary winding. A first terminal of the charge-pump capacitor is coupled to the second terminal of the secondary winding. The bridge rectifier circuit is coupled to the first terminal of the secondary winding and a second terminal of the charge-pump capacitor. The unidirectional controlled switch is reversely coupled to one of multiple diodes in the bridge rectifier circuit, and configured to be on or off according to a control voltage selectively. The output capacitor is coupled to the bridge rectifier circuit and configured to provide an output voltage according to the secondary current.

Abstract: A switching regulator has: a switching device; a rectifying device having the anode thereof connected to an output terminal from which an output voltage is output; an inductor arranged between the switching device and the output terminal; a controller having an error amplifier configured to produce an error signal commensurate with a difference between a voltage commensurate with the cathode voltage of the rectifying device and a reference voltage, the controller using the cathode voltage of the rectifying device as a supply voltage and turning ON and OFF the switching device according to the cathode voltage of the rectifying device; a monitor configured to monitor a current that flows through the inductor; and a current varier configured to increase, based on the result of monitoring by the monitor, a current that flows through the rectifying device with increase in the current flowing through the inductor.

Abstract: A switching power supply device includes a switching transistor, a sense resistor connected to the switching transistor in series and on which a sense voltage generates when the switching transistor is turned on, a transformer including a first winding to which an input voltage is applied when the switching transistor is turned on and a second winding connected to a load, an optocoupler in which an optocoupler current is generated based on an output voltage on the second winding side, a load power detection circuit that generates a load power signal in accordance with a turn-on period of the switching transistor, a turn-on period control circuit, a turn-off period control circuit, and an SRFF circuit.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

Abstract: System and method are provided for protecting a power converter. The system includes a first comparator, and an off-time component. The first comparator is configured to receive a sensing signal and a first threshold signal and generate a first comparison signal based on at least information associated with the sensing signal and the first threshold signal, the power converter being associated with a switching frequency and further including a switch configured to affect the primary current. The off-time component is configured to receive the first comparison signal and generate an off-time signal based on at least information associated with the first comparison signal. The off-time component is further configured to, if the first comparison signal indicates the sensing signal to be larger than the first threshold signal in magnitude, generate the off-time signal to keep the switch to be turned off for at least a predetermined period of time.

Abstract: The present application is a converter having a low loss snubber. The low loss snubber of the converter includes a clamping winding, a first capacitor, and a second capacitor. The clamping winding is magnetically coupled with a primary winding of a transformer of the converter. The primary winding to a secondary winding of the transformer leakage inductance energy is recovered by storing the energy in the second capacitor. When the second capacitor is discharging, the energy in the second capacitor may be further transferred to the first capacitor. When the first capacitor is discharging, energy in the first capacitor may be further returned to the power source. Therefore, the energy in the first capacitor and the energy in the second capacitor may not be consumed by a resistor, and power consumption of the low loss snubber may be decreased.

Abstract: A power supply apparatus supplies a power supply voltage VDD. The power supply apparatus includes a compensation circuit in addition to a main power supply. The compensation circuit receives, via its input, as a feedback signal, a detection signal VS that corresponds to the power supply voltage VDD. The compensation circuit has input/output characteristics fIO that correspond to the characteristics of the main power supply and the characteristics of a target power supply to be emulated. The compensation circuit injects or otherwise draws a compensation current iCOMP that corresponds to the detection signal VS to or otherwise from a node for generating the power supply voltage VDD.

Abstract: A power source device includes a transformer including a primary winding and a secondary winding; a first switch portion connected with the primary winding in series; a circuit including a capacitor and a second switch portion connected in series and connected with the primary winding in parallel; a controller for controlling conduction between the first switch portion and the second switch portion, wherein the first switch portion and the second switch portion are alternately conducted to generate an output voltage at a secondary side of the transformer, a detecting portion for detecting a current flowing through the first switch portion. The controller controls conduction of the first switch portion and the second switch portion so that a value of the current detected by the detecting portion does not exceed a threshold depending on conduction times of the first switch portion and second switch portion.

Abstract: A switching element driving device includes: a drive circuit that is connected between an element driving power supply and a circuit ground and outputs a driving signal to a driving switching element; a capacitor that is connected between the circuit ground and a reference ground to which a potential reference side conduction terminal of the driving switching element is connected; and a regulator that charges and discharges so that the capacitor has a predetermined terminal voltage. The regulator discharges the capacitor when the terminal voltage exceeds an upper limit value, and charges the capacitor when the terminal voltage falls below a lower limit value.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for fault detection in a power control system. In one aspect, a method includes measuring a plurality of values of a feedback voltage from a power control system over a period of time; determining a rate of feedback voltage change based on the measured values of the feedback voltage and a duration of the period of time; determining, with a controller, that the determined rate of feedback voltage change is smaller than a threshold rate of change; and in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting a fault indication signal to the power control system.

Abstract: A device and method are provided for saving power and electricity in a charging device including external power supplies and battery chargers having a primary circuit and a secondary circuit where a switch is located in the primary circuit and a current sensing device in the secondary circuit to sense when there is a drop in current in the secondary circuit or no current in the secondary circuit because the load such as a cell phone or tablet is charged and when this occurs the switch in the primary circuit is opened and the primary circuit no longer draws power from the source of power until the switch in the primary circuit is closed by either a user activating a switch to reenergize the charging device, where the switch may be powered by an on-board battery to close the primary circuit, or where a control circuit is activated by a program in the load or device to be charged, such that the charging device will cycle on and off according to an external app program residing on the device to be charged or some

Abstract: An electrical circuit for a power supply includes a primary-side controller integrated circuit (IC) that outputs a drive signal on a switch pin to control a switching operation of a switch that is coupled to a primary winding of a transformer. The primary-side controller IC places the switch pin at high impedance during a sense window and turns on the switch in response to sensing a dynamic detection signal on the switch pin during the sense window. The dynamic detection signal is induced by a secondary-side controller IC by controlling switching of a switch that is coupled to a secondary winding of the transformer when the output voltage drops below a predetermined threshold during standby or other low load conditions.

Abstract: A power source apparatus comprises: a transformer that insulates a primary system and a secondary system and uses primary/secondary windings to transform an input voltage into an output voltage; a switching control device that is disposed in the primary system to drive the primary winding, and an output monitor device that is disposed in the secondary system to monitor the output voltage. The transformer includes a first auxiliary winding disposed in the primary system and a second auxiliary winding disposed in the secondary system. The output monitor device drives the second auxiliary winding to generate an induced voltage in the first auxiliary winding when the output voltage becomes smaller than a predetermined threshold voltage. The switching control device temporarily stops driving of the first winding upon detecting a light load state and resumes the driving of the first winding upon detecting the induced voltage in the first auxiliary winding.

Abstract: In one embodiment, a zero-crossing detection circuit can include: (i) a first detection circuit configured to detect a current through a main transistor of a main circuit of a switching power supply, and to generate a voltage sense signal that represents the current through the main transistor; (ii) a second detection circuit configured to detect if quasi-resonance occurs in the main circuit, the second detection circuit being configured to generate at least one pulse signal when the quasi-resonance is detected; and (iii) a control circuit configured to receive the at least one pulse signal and the voltage sense signal, to turn the main transistor off when the current through the main transistor reaches a predetermined value, and to turn the main transistor on when the at least one pulse signal is active.

Abstract: A cross regulation circuit for multiple outputs, includes an input end and at least two output ends. A first output end of the at least two output ends is connected to a feedback circuit. The feedback circuit is connected to the input end and used for maintaining the output voltage of the first output end by adjusting the input end. A first resistor and a first inductor are sequentially connected in series on the upstream of each of other output ends than the first output end and are used for performing cross regulation. In the cross regulation method of the circuit, simultaneous equations are established through parasitic inductance on any output branch and load thereof as well as parasitic inductance on the first output branch so as to obtain the inductance of the first inductor and the capacitance of the first resistor.

Abstract: A control circuit can include: a blanking time control circuit configured to generate a blanking control signal according to a peak current of a main switch of a power stage circuit of a flyback converter; a sampling time control circuit configured to generate a sampling time control signal according to the blanking control signal and a feedback voltage signal; and a voltage detection circuit configured to receive the feedback voltage signal and the sampling time control signal, and to determine the time of detecting the feedback voltage signal according to the sampling time control signal to obtain a detection signal for controlling the main switch, where the voltage detection circuit stops detecting the feedback voltage signal when the blanking control signal is active, and the period during which the blanking control signal is active is adjustable along with the peak current.

Abstract: Methods of operating switching power supplies are disclosed. A power supply has a transformer and a switch coupled to the primary side of the transformer for controlling the current flow through the primary side of the transformer. A method includes determining the output voltage of the power supply. A first minimum switching frequency is generated for driving the switch in response to the output voltage being greater than a nominal output voltage and less than a predetermined voltage. A second minimum switching frequency is generated for driving the switch in response to the output voltage being equal to or greater than the predetermined voltage, wherein the first minimum switching frequency is greater than the second minimum switching frequency.

Abstract: Disclosed is a resonant DC/DC converter, comprising a DC source unit, a power conversion unit, a control unit and an output rectification unit, wherein the power conversion unit comprises a resonance circuit and at least a phase-shift circuit, the phase-shift circuit comprises at least a pair of first switching elements S1, S2 and a phase-shift inductance La, one end of the phase-shift inductance is connected with the bridge node of the first switching element S1, S2, and the other end is coupled to the resonance circuit; the control unit drives each switching element of the power conversion unit, and the switching frequency and the phase shifting angle of the first switching element are calculated according to the feedback signals of the output rectification unit.

Abstract: In one embodiment, a method of controlling a switching power supply, can include: (i) generating a driving current signal that follows a waveform of a sense voltage signal, where the sense voltage signal is related to a current through a collector of a transistor that is configured as a power switch of the switching power supply, where the collector is coupled to an inductive element of the switching power supply; (ii) providing the driving current signal to a base of the transistor, where the transistor is in a saturated conduction state when a pulse-width modulation (PWM) signal is active; and (iii) releasing charge accumulated on the base when the PWM signal is inactive to turn off the transistor.

Abstract: A power supply system includes a flyback power converter and a control circuit coupled to the flyback power converter. The power converter includes an input, an output, a transformer having a plurality of windings coupled between the input and the output, a first power switch coupled to the transformer and a clamping circuit having a capacitor, a diode, and a second power switch coupled to one of the plurality of windings. The capacitor and the diode are coupled in parallel between the winding and the second power switch. The control circuit is configured to operate the power converter in a discontinuous conduction mode and control the first power switch and the second power switch at a fixed frequency to achieve substantially zero voltage switching during turn on of the first power switch. Various other example power supply systems, power converters, and methods for controlling a power converter are also disclosed.

Abstract: A switching power supply includes a first switching element connected between a primary winding of a transformer for the switching power supply and the ground, a shunt regulator serving as an output voltage detection circuit configured to detect an output voltage on a secondary winding side of the transformer, a photocoupler configured to transmit the output voltage to a control circuit, a second switching element configured to receive a stop signal for stopping operation of the switching power supply, and a photocoupler drive circuit configured such that when the second switching element has received the stop signal, power output from a low-frequency transformer power supply or the switching power supply is supplied to the photocoupler, and the stop signal is transmitted to the control circuit via the photocoupler.

Abstract: A method of controlling an isolated converter can include: (i) sampling and holding an output voltage of the isolated converter during a present switching cycle to generate a reference voltage signal that is proportional to the output voltage; (ii) comparing, in a predetermined time interval before a next switching cycle, the output voltage against the reference voltage signal, and activating a wake-up signal when the output voltage is less than the reference voltage signal, in order to control a voltage at a secondary winding to represent a variation of the output voltage; (iii) detecting a voltage of the primary winding or the secondary winding, and generating a voltage detection signal; and (iv) controlling the power switch according to the voltage detection signal, in order to maintain the output voltage as an expected voltage.

Abstract: According to some embodiments, an electronic drive circuit is disclosed. The electronic drive circuit includes an energy storage device and a first bridge circuit coupled to the energy storage device. The first bridge circuit includes at least one leg having two switches. The electronic drive circuit also includes a transformer. The transformer includes a first winding coupled to the first bridge circuit and a second winding coupled to the energy storage device through a center tap. The electronic drive circuit further includes a second bridge circuit coupled to the second winding of the transformer. The second bridge circuit includes a pair of switches operable to conduct in both directions and block voltage in both directions.

Abstract: According to some aspects of the present disclosure, isolated power supplies and corresponding control methods are disclosed. Example isolated power supplies include a transformer, at least one power switch coupled to the transformer, a controller, an output terminal, and a feedback circuit coupled to the output terminal to sense the output voltage and compare the sensed output voltage to a voltage reference. The power supplies include a fault detection circuit to sense the output voltage, compare the sensed output voltage to a fault reference, and modify a feedback signal when the sensed output voltage exceeds the fault reference. The power supplies also include a single isolation device coupled between the feedback circuit and the controller. The controller is operable to control the power switch based on the feedback signal and to detect a fault condition when a slew rate of the feedback signal exceeds a fault threshold slew rate value.

Abstract: System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

Abstract: A method includes generating output power based on a switching signal, comparing the output power to a target power, increasing the output power using a pulse frequency modulation (PFM) and pulse width modulation (PWM) when the output power is less than the target power, and decreasing the output power using the PFM and PWM when the output power is greater than the target power. An apparatus includes a power regulator configured to generate output power based on a switching signal, and a pulse frequency and width modulation (PFWM) controller coupled to the power regulator, and configured to compare the output power to a target power and to increase or decrease the output power using a PFM and pulse PWM according to the comparison result.

Abstract: A control device for a switching converter having a transformer, with a primary winding receiving an input quantity, a secondary winding providing an output quantity, an auxiliary winding providing a feedback quantity, and a switch element. The control device has a processing module for generating a control signal for switching the switch element on the basis of the feedback quantity in order to regulate the output quantity via alternation of phases of storage and transfer of energy. The processing module controls the end of the transfer phase by comparing the feedback quantity with a comparison threshold. A discrimination circuit generates a signal for discrimination between the presence of a short circuit on the output or the fact that the input quantity is lower than a threshold. The processing module controls the end of the energy-transfer phase also on the basis of the discrimination signal.

Abstract: The disclosure relates to a control arrangement for a SMPS, the control arrangement comprising: an input terminal configured to receive a feedback-signal (V1) representative of an output of the SMPS; a normal-mode-processing-arrangement-configured to process the feedback-signal and provide a normal-mode-control-signal for operating the SMPS in a normal mode of operation; a burst-mode-processing-arrangement configured to process the feedback-signal and provide a burst-mode-control-signal for operating the SMPS in a burst mode of operation; and a feedback-control-processing-arrangement configured to operate the SMPS such that the feedback signal in the normal mode of operation has a predetermined relationship with the feedback signal in the burst mode of operation.

Abstract: A control method is used in a switching mode power supply to improve dynamic load response and switching loss. A PWM signal is provided to control a power switch and has a switching frequency. A cross voltage of a transformer in the switching mode power supply is detected to provide a de-magnetization time. The switching frequency is controlled in response to a sleep signal and a compensation voltage, which is generated based on an output voltage of the switching mode power supply. The sleep signal is provided in response to the de-magnetization time and a current sense signal, a representative of a winding current of the transformer. The switching frequency is not less than a first minimum value if the sleep signal is deasserted, and not less than a second minimum value if the sleep signal is asserted. The second minimum value is less than the first minimum value.

Abstract: Control methods and related power controllers diminish audible noise in a power supply capable of performing valley switching. The power supply has an inductive device and a power switch. When the power switch is OFF, a winding voltage of the inductive device oscillates to provide an oscillation signal with at least one signal valley. An occurrence number of the signal valley is detected, and is compared with a lock number. When the occurrence number and the lock number fit a predetermined condition, the power switch is turned ON to start a cycle time at a start moment. Whether the start moment falls within an expectation window is checked. The lock number is changed if the start moment falls outside of the expectation window.