Abstract: A flyback converter control architecture is provided in which primary-only feedback techniques are used to ensure smooth startup and detection of fault conditions. During steady-state operation, secondary-side regulation is employed. In addition, current limits are monitored during steady-state operation using primary-only feedback techniques to obviate the need for a secondary-side current sense resistor.

Abstract: A power provider includes: first, second, and third inductors; a first transistor connected to the second inductor; a second transistor connected to the third inductor; and a power integrated chip (IC) including input terminals connected to the first, second, and third inductors, and an output terminal connected to a power line. The power provider may supply the power voltage using the first inductor and the power IC when power current is less than a first reference value, supply the power voltage using the second inductor, the first transistor, and the power IC when the power current is greater than the first reference value and less than a second reference value, and supply the power voltage using the second and third inductors, the first and second transistors, and the power IC when the power current is greater than the second reference value.

Abstract: In one embodiment, a method includes identifying at a first powered device in communication with power sourcing equipment, a second powered device in communication with the first powered device, wherein the first powered device is receiving high voltage pulse power from the power sourcing equipment, notifying the power sourcing equipment of the second powered device at the first powered device, and performing a low voltage power initialization at the first powered device with the second powered device before passing the high voltage pulse power to the second powered device.

Abstract: A resonant power conversion device includes: a main circuit provided with a semiconductor switch, a capacitor and an inductor connected in series or parallel to the semiconductor switch; and a drive circuit configured to drive the switching element. The switching element enters an off-state or an on-state depending on a control voltage input to a gate terminal, and the drive circuit includes two or more types of control voltages, as a control voltage at which the switching element enters an off-state.

Abstract: A method includes detecting a first current flowing through a first clamping device coupled to a gate of a power switch, determining whether an inductor current reduces to zero based upon a first comparison between the first current and a first predetermined current level, and after determining the inductor current reduces to zero, determining whether a drain voltage of the power switch enters a valley of a resonant ringing based upon a second comparison between the first current and the first predetermined current level.

Abstract: The bidirectional insulating DC-DC converter shares high/low voltage terminals, a cooling passage, a housing, and a control board, and two independent step-down circuit (10) and step-up circuit (20) are formed in parallel to perform a bidirectional DC power conversion. A high voltage applied from a high voltage battery HV is stepped down through the step-down circuit (10) and output to a low voltage battery LV. On the other hand, a low voltage applied from the low voltage battery LV is stepped up through the step-up circuit (20) and output to the high voltage battery HV. The step-down circuit (10) is formed as an active clamp forward converter circuit, and the step-up circuit (20) is formed as an active clamp flyback converter circuit.

Abstract: A method for determining user configurations of services in a radio communication network is performed in a support system node, and includes ranking users of a service based on frequency of occurrences of user reconfiguration in the radio communication network, creating a linear regression model of user configuration for a plurality of users of the service in the radio communication network, identifying a user configuration per user of the service for a selected number of ranked users by fitting the selected number of ranked users in the linear regression model, in order to reduce user reconfiguration of the service, and providing the identified user configuration per user to the selected number of ranked users. A support system node, a computer program and a computer program for determining user configurations of services in a radio communication network are also presented.

Abstract: A power device fault detection circuit includes a first fault detector configured to measure an output signal of at least one power device and output a first fault signal when a voltage of the output signal of the at least one power device exceeds a first voltage reference level after a first time period; and a second fault detector configured to measure an output signal of the at least one power device and output a second fault signal when a voltage of the output signal of the at least one power device exceeds a second voltage reference level after a second time period, where the first time period implemented by the first fault detector is shorter than the second time period implemented by the second fault detector.

Abstract: A power source apparatus including a control unit configured to output a control signal to a switching element to switch a target voltage of an output voltage from a transformer. In a case of increasing the output voltage, the control unit outputs the control signal having a first duty when the target voltage is lower than a first threshold value, and outputs the control signal having a second duty larger than the first duty when the target voltage is switched to a value equal to or higher than the first threshold value. In a case of reducing the output voltage, the control unit outputs the control signal having the second duty when the target voltage is equal to or higher than a second threshold value, and outputs the control signal having the first duty when the target voltage is switched to a value lower than the second threshold value.

Abstract: A control circuit applied to a power adapter includes a voltage conversion unit and a switch control unit. The voltage conversion unit is configured to: receive a first direct current voltage, and generate a second direct current voltage based on the first direct current voltage, where when the first direct current voltage is lower than a working voltage of the switch control unit, the voltage conversion unit is configured to boost the first direct current voltage, to obtain the second direct current voltage. The switch control unit is configured to: receive the second direct current voltage from the voltage conversion unit, and use the second direct current voltage as a power supply voltage of the switch control unit.

Abstract: A charging device of the present invention includes a DC-DC converter, a charging circuit that charges a secondary battery, a power supply voltage detecting circuit that detects an input voltage Ve, an output voltage setting circuit that sets an output voltage of the DC-DC converter, and a charging control section that controls the charging circuit and the output voltage setting circuit based on the input voltage Ve, and the charging control section increases the output voltage of the DC-DC converter by a predetermined voltage in a stepwise manner while monitoring the input voltage Ve, and in a case where the input voltage Ve is decreased to a first threshold voltage Vth1 or less before the output voltage of the DC-DC converter increases to a rated charging voltage, the charging control section keeps the output voltage of the DC-DC converter at a voltage that is one step lower than a voltage at a time point of the case.

Abstract: A two-stage driver supplies current to an LED load. A first stage of the driver generates a bulk voltage. A second stage has a flyback transformer with a primary winding and a secondary winding. The second stage generates an output voltage to cause LED load current. The primary winding is turned on and off by a gating signal. Control logic within the second stage is responsive to initially turning on the driver to perform a startup short circuit test of the output circuit by applying a gating signal with a short on-time and a low switching frequency. If the output circuit is not shorted, the control logic increases the on-time and the switching frequency to detect if an output current is excessive. If the output current is not excessive, the control logic adjusts the on-time and the frequency to provide sufficient current to illuminate the LED load.

Abstract: In this invention we introduce the concept of energy injection in a resonant circuit with initial conditions which is part of almost all of the present topologies. The patent will present in details several methods of energy injection in a resonant circuit with initial conditions and how it is applies to different topologies. The patent presents also a simple and economical method of driving the clamp switch in a flyback topology operating in discontinuous mode and a bias circuit in a flyback topology wherein the output voltage varies over a large range.

Abstract: A power converter controller includes an analog to digital converter (ADC) to generate a digital representation of a feedback signal of a power converter, the feedback signal being received from a compensator of the power converter and being based on an output voltage of the power converter. A nonlinear gain block of the power converter controller receives the digital representation of the feedback signal and generates a transformed digital representation of the feedback signal using a nonlinear function. A switch control block of the power converter controller controls an on-time of a primary-side switch of the power converter based on the transformed digital representation of the feedback signal.

Abstract: A power supply control circuit for a switch mode power supply converter, and a power supply control method using the control circuit. The control circuit includes an auxiliary boosting unit, a main control unit and an auxiliary winding unit. The main control unit is configured to control the power switch in a power stage circuit to turn on or to be off, and to supply power to the auxiliary boosting unit. The auxiliary boosting unit is configured to provide auxiliary power for the main control unit, and to self-adaptively adjust the auxiliary boosting unit's own average switching frequency based on a load state of the main control unit. The auxiliary winding unit is configured to couple energy by means of a magnetic element in the power stage circuit, to generate an output voltage.

Abstract: A power converter provides a low-voltage output using a full-bridge fault-tolerant rectification circuit. The output circuit uses controlled switches as rectifiers. A fault detection circuit monitors circuit conditions. Upon detection of a fault, the switches are disabled decoupling the power converter from the system. A common-source dual MOSFET device includes a plurality of elements arranged in alternating patterns on a semiconductor die. A common-source dual synchronous rectifier includes control circuitry powered from the drain to source voltage of the complementary switch. A DC-to-DC transformer converts power from an input source to a load using a fixed voltage transformation ratio. A clamp phase may be used to reduce power losses in the converter at light loads, control the effective output resistance of the converter, effectively regulate the voltage transformation ratio, provide narrow band output regulation, and control the rate of change of output voltage for example during start up.

Abstract: A grounded voltage protection circuit for a linear drive circuit includes an AC-DC power supply module, a first voltage protection module, an LED module, a drive IC and a linear current adjustment module. Through the cooperation of the first voltage protection module, the drive IC and the linear current adjustment module, when a DC voltage signal output by the AC-DC power supply module exceeds a first preset voltage value, the first voltage protection module outputs the first preset voltage signal to prevent the drive IC and the LED module from being damaged due to the overvoltage output by the AC-DC module, and avoid the transient impulse voltage in the entire voltage protection circuit, thereby enabling the voltage protection circuit to pass the CEC certification.

Abstract: A power distribution system includes a plurality of power distribution modules connected to at least one power supply and configured to receive power therefrom. A power distribution bus connects the power distribution modules of the plurality of power distribution modules in parallel. The plurality of power distribution modules executes a distributed system policy management protocol over the power distribution bus to control a supply of available power from the at least one power supply to loads connected to USB charging ports of the power distribution modules.

Abstract: A two-stage driver supplies current to a light emitting diode (LED) load. The driver includes a first stage and a second stage. The second stage is configured to generate a desired current through the LED load. The second stage has a flyback converter having a flyback transformer with a primary winding and a secondary winding. The primary winding is turned on and off by a gating signal. An induced voltage in the secondary winding rings when a current in the secondary winding is discharged. The flyback converter is configured to turn on the primary winding only during a detected valley in the ringing of the secondary winding. If the primary winding is turned on during a detected valley different from the previous detected valley, a valley jump is detected and the switching frequency is adjusted.

Abstract: In a start-up control in which primary-side direct-current (DC) terminals and secondary-side DC terminals are charged by an external power supply outside a power conversion device, initially, one-side DC terminals are charged by the external power supply while switching operations of the primary-side bridge circuit and the secondary-side bridge circuit are stopped. Subsequently, a bridge circuit that is connected to the DC terminals not charged by the external power supply stops the switching operation and operates in a diode rectifying mode, while a bridge circuit that is connected to the DC terminals charged by the external power supply performs the switching operation and outputs an AC voltage whose voltage pulse width has been subjected to a variable control so that the voltage pulse width is smaller for a greater voltage difference of the charged DC terminals from the uncharged DC terminals.

Abstract: Apparatus and associated methods relate to providing an integrated circuit package having (a) a bypass circuit in parallel with an inductor and (b) a logic circuit configured to control the bypass circuit for conductivity modulation. In an illustrative example, in response to a corresponding load transient, the logic circuit may include a state machine configured to generate different control signals for the bypass circuit to control the timing and/or quantity of energy transfer from the inductor to a load. The bypass circuit may include a first semiconductor switch and a second semiconductor switch connected in anti-series. In some implementations, the power stage and the bypass circuit may be operated, for example, in numerous operational modes to dynamically modulate conductivity across the terminals of the inductor in a power supply to advantageously result in a smaller undershoot and overshoot.

Abstract: The present invention discloses a power converter, a switch control circuit, and a short circuit detection method for current sensing resistor of the power converter. The power converter includes: a transformer, a power switch, a current sensing resistor and a switch control unit. The current sensing resistor has one end coupled to the power switch and another end coupled to ground. The switch control unit generates the operation signal to control the power switch. The switch control unit generates a first sample-and-hold voltage at a first time point and a second sample-and-hold voltage at a second time point according to a voltage across the current sensing resistor. When a voltage difference between the first sample-and-hold voltage and the second sample-and-hold voltage is smaller than a reference voltage, it is determined that a short circuit occurs in the current sensing resistor.

Abstract: An image forming apparatus controls a power supply circuit by supplying a control signal to the power supply circuit, and detects an electrical characteristic, e.g. an electrostatic capacitance generated between an image carrier and a developing member or a current caused to run by applying a development voltage to the developing member. The apparatus determines a change pattern of a duty ratio of a PWM signal including the control signal on the basis of the electrical characteristic. The apparatus changes the duty ratio as time passes according to the determined change pattern and outputs the control signal to the power supply circuit.

Abstract: A power supply system comprises: a switched-capacitor converter, a transformer, and a voltage converter. The switched-capacitor converter includes multiple capacitors. The multiple capacitors are controllably switched in a circuit path including a primary winding of the transformer to convert the first voltage into a second voltage. The voltage converter converts the first voltage produced by the switched-capacitor converter into the second voltage that powers a load.

Abstract: A power factor correction (PFC) controller applied to a primary side of a power converter includes a feedback pin, a sensing pin, a current detecting circuit, an output voltage detecting circuit, and a determination circuit. The current detecting circuit is coupled to the feedback pin and the sensing pin for detecting an output current of a secondary side of the power converter according to a feedback voltage of the feedback pin and a sensing voltage of the sensing pin. The output voltage detecting circuit is coupled to the feedback pin for detecting an output voltage of the secondary side of the power converter according to the feedback voltage. The determination circuit is coupled to the current detecting circuit and the output voltage detecting circuit for turning on or turning off a PFC circuit coupled to the power converter according to the output current and the output voltage.

Abstract: A power supply control device includes a charge circuit, a detection circuit, and a charge control circuit. The charge circuit charges a capacitor coupled to a power supply voltage node based on a full-wave rectified voltage. The charge control circuit enables a charge mode of the charge circuit when the detection circuit detects that a power supply voltage is less than a first threshold voltage. The charge control circuit disables the charge mode when the detection circuit detects that the power supply voltage reached a second threshold voltage. The charge control circuit sets a charge capacity of the charge circuit in a second charge mode period according to a length of a first charge mode period.

Abstract: A power supply circuit has a push-pull portion having a transformer; first and second terminals of the primary winding, each connected to ground via first and second switches; an inductor connected between an input voltage and the primary winding centre tap via a third switch; an energy storage portion connected between the primary winding and ground, and to the inductor via a fourth switch; a controller arranged to monitor the input voltage and to apply partially overlapping first and second PWM signals to the first and second switches; when input voltage is between first and second thresholds, the controller closes the third switch and opens the fourth switch; above the second threshold, the controller applies a third PWM signal to the third switch and opens the fourth switch; and below the first threshold, the controller closes the third switch and applies a fourth PWM signal to the fourth switch.

Abstract: A circuit and method for providing high-voltage radio-frequency (RF) energy to an instrument at multiple frequencies includes a plurality of inputs each configured to receive an RF voltage signal oscillating at a corresponding frequency, and a step-up circuit for generating magnified RF voltage signals based on the received RF voltage signals. The step-up circuit includes an LC network operable to isolate the RF voltage signals at the plurality inputs from one another while preserving a voltage magnification from each input to a common output at each of the corresponding frequencies.

Abstract: A controller of a current resonance switching power supply apparatus configured to supply a constant output voltage to a load. The current resonance switching power supply apparatus includes a resonance circuit, and generates a feedback signal indicative of an error between the output voltage and a target voltage. The controller includes a load current detection circuit that receives a part of a resonance current of the resonance circuit, performs averaging and outputs a load current signal, and a standby detection circuit that receives the feedback signal and the load current signal, and determines that the load is in a standby mode upon detecting that the load current signal is lower than a first threshold and the feedback signal is lower than a second threshold, and is in a normal mode upon detecting that the feedback signal continues to be higher than the second threshold for more than a predetermined time.

Abstract: A control circuit for a switching converter having a main power switch and a freewheeling circuit, can be configured to: control the freewheeling circuit to be turned on in a first time interval after the main power switch is turned off; control the freewheeling circuit to be turned on in a second time interval after the first time interval, in order to reduce turn-on loss of the main power switch; and where the first time interval and the second time interval do not overlap each other in a switching cycle.

Abstract: A control circuit for a resonant converter has a communication interface, a memory, and a primary switching control circuit. The memory provides a frequency setting signal capable of being programmed through a communication interface, the primary switching control circuit provides a first control signal to control a high-side switch and a second control signal to control a low-side switch. When the resonant converter works in an open loop mode, a frequency of the first control signal and the second control signal is determined by the frequency setting signal, an on-time period of the high-side switch equals an on-time period of the low-side switch, less than half of a resonant period.

Abstract: The invention relates to a synchronous converter (10) comprising a transformer (11A, 11B) having a predefined winding ratio, which couples a supply-side (12) and a load side (13) of the synchronous converter (10), which are each allocated limit current intensities (15?, 15?, 24?, 24?); detection means (14), which are configured to detect a current intensity (15) on one side (12) from the supply side (12) and the load side (13); conversion means (16), which are configured to provide the limit current intensities (24?, 24?) from the other side (13) from the supply-side (12) and the load side (13), converted via the predefined winding ratio, as corresponding limit current intensities (15*, 15**) on the one side (12); and comparison means (17), which are configured to compare the detected current intensity (15) with the limit current intensities (15?, 15?) of the one side (12) and with the corresponding limit current intensities (15*, 15**) on the one side (12).

Abstract: An apparatus includes comprises an auxiliary switch, a transformer and an auxiliary diode. The auxiliary switch is configured to be turned on prior to turning on a first power switch of a multi-level boost converter. The transformer has a primary winding connected between the first power switch and the auxiliary switch. The auxiliary diode is coupled between a secondary winding of the transformer and an output terminal of the multi-level boost converter. The transformer and the auxiliary switch are configured such that the first power switch is of zero voltage switching, and the auxiliary switch is of zero current switching.

Abstract: A device includes a driving portion, a transformer having a primary winding and a secondary winding, the secondary winding generating an output voltage, the driving portion being connected across the secondary winding so that the output voltage is applied to the driving portion, a switching element connected in series to the primary winding, a first controller provided in a primary side of the transformer for controlling the switching element, and a second controller supplied with the output voltage. The second controller is configured to perform, during implementation of a burst switching control, transmitting a stop signal to the first controller when the output voltage exceeds a first voltage, and transmitting, after transmission of the stop signal, a resumption signal to the first controller when the output voltage falls below a second voltage lower than the first voltage.

Abstract: A snubber circuit configured to be coupled to a switching circuit, comprises a snubber capacitor; a diode; and a coil, wherein the switching circuit includes an upper switch element coupled between a high potential node and a switch node, a lower switch element coupled between the switch node and a reference potential node, and a bypass capacitor coupled between the high potential node and the reference potential node, a positive electrode of the snubber capacitor is configured to be coupled to the high potential node, an anode of the diode is coupled to a negative electrode of the snubber capacitor, and a cathode of the diode is coupled to the switch node, and one end of the coil is coupled to the negative electrode of the snubber capacitor, and another end of the coil is coupled to the reference potential node.

Abstract: A semiconductor device disposed on a primary side of a system generating a secondary side voltage in an insulated form from a primary side voltage includes: a signal generation circuit configured to generate a voltage information signal for transmitting voltage information based on the primary side voltage to a secondary side of the system in the insulated form.

Abstract: An operating condition monitor (100) for monitoring an operating condition of a transistor-based power converter (102), comprising: a sensing apparatus (106) configured to measure a turn-off transient energy of the power converter (102), a processor (108) in communication with the sensing apparatus (106) to receive the measurement of the turn-off transient energy, the processor being configured to: compare the measurement of the turn-off transient energy to a threshold; and issue an event signal based on the comparison to the threshold meeting a comparison criterion. A method (200, 200?) of monitoring an operating state of a transistor-based power converter is also disclosed.

Abstract: A control unit determines a polarity of an actual voltage value of an AC power supply if it is either positive or negative based on a detection voltage thereof detected by the voltage detector. The control unit alternately actuates a set of a first switch and a fourth switch and another set of the second switch and a third switch each time when it is determined that the polarity of the actual voltage value of the AC power supply changes. A second reactor is disposed at at least one of first and second positions. The first position is located between a first AC side terminal and a connection point located between the first switch and the second switch. The second position is located between a second AC side terminal and a connection point located between the third switch and the fourth switch.

Abstract: A semiconductor device includes a plurality of first transistor cells and a plurality of second transistor cells that are electrically connected in parallel between a collector electrode and an emitter electrode. A gate voltage on each of the plurality of first transistor cells is controlled by a first gate interconnection. A gate voltage on each of the plurality of second transistor cells is controlled by a second gate interconnection. A drive circuit is configured to: apply an ON-voltage of the semiconductor device to each of the first and second gate interconnections when the semiconductor device is turned on; and after a lapse of a predetermined time period since start of application of the ON-voltage, apply an OFF-voltage of the semiconductor device to the second gate interconnection and apply an ON-voltage to the first gate interconnection.

Abstract: An active clamp switching power converter circuit includes a sensing circuit that generates a sensed auxiliary winding voltage of an auxiliary winding around the core having a same polarity as the secondary winding. A controller controls switching of a power switch coupled to the primary winding to control current through the primary winding and controls switching of an active clamp switch based on the sensed voltage to control leakage energy when the power switch is turned off. The controller regulates timing of the switching to achieve a zero voltage switching condition prior to turning on the power switch for power efficient operation.

Abstract: An apparatus (such as a power converter circuit) includes s primary winding, an auxiliary winding, and an over-voltage protection circuit (such as a controller and corresponding one or more circuit components). The primary winding receives an input voltage. The auxiliary winding is magnetically coupled to the primary winding. The primary winding receives energy from the input voltage, the auxiliary winding receives the energy from the primary winding. The over-voltage protection circuit controls conveyance of the energy received from the primary winding through a discharge circuit path to a reference voltage (such as ground). Conveyance of the energy (as received from the auxiliary winding) associated with the input voltage through the discharge circuit path prevents damage to a respective power converter circuit during exposure of the input voltage to a power surge condition such as due to lightning.

Abstract: An apparatus for controlling a power converter includes an analog-to-digital converter to generate a digital representation of a voltage sense signal indicative of an input voltage of the power converter. The apparatus includes a first comparison circuit to generate a first comparison signal using a current sense signal indicative of a current through a primary-side switch of the power converter. The apparatus includes a gate driver to provide a gate drive signal to the primary-side switch based on a control signal, and a digital controller. The digital controller is configured to produce a time scalar value using the digital representation of the voltage sense signal, produce a timing signal using the control signal and the first comparison signal, scale the timing signal using the time scalar value, and adjust a timing of the control signal to limit a peak current through the primary-side switch based on the scaled timing signal.

Abstract: An apparatus such as a DC-DC power converter including a switch, an ON-time controller, and a compensator operates in a constant ON-time control mode. Over multiple control cycles, the ON-time controller controls an ON-time duration of activating the switch and generation of an output voltage to power a dynamic load. The compensator, in communication with the ON-time controller, adjusts the ON-time duration of activating the switch depending on a magnitude of output current delivered by the output voltage to the dynamic load. For example, during heavier load conditions when the dynamic load consumes a higher amount of current, and in which internal resistive losses of the power supply become more substantial, the compensator increases the ON-time duration of activating the switch, resulting in operation of the power supply and switch closer to a desired frequency setpoint.

Abstract: A synchronous rectifier converts an AC input into a DC output. The synchronous rectifier has four switches controlled by four switch control modules. Each switch is connected between a different AC component and either the DC output or ground. Each switch control module has digitally assisted “switch on” circuitry that detects “on” bounces in the corresponding AC component to control when to turn on the corresponding switch and digitally assisted “switch off” circuitry that detects “off” bounces in the AC component to control when to turn off the corresponding switch. The “switch on” circuitry has a digitally assisted comparator to detect threshold crossings in the AC component, and the “switch off” circuitry has a digitally assisted programmable delay cell to turn off the switch for a predetermined duration following each detected threshold crossing.

Abstract: A power supply circuit that generates an output voltage from an AC voltage. The power supply circuit includes a rectifier circuit that rectifies the AC voltage, an inductor receives a rectified voltage from the rectifier circuit, a transistor that controls an inductor current flowing through the inductor, and an integrated circuit that performs switching of the transistor. The integrated circuit includes an error output circuit that outputs an error between a feedback voltage and a reference voltage, a target value generating circuit that generates a target value of the inductor current based on the error, an adjustment circuit that adjusts the target value, first and second comparison circuits that compare the inductor current with a predetermined value and with the target value, respectively, and a drive circuit that turns on the transistor when the inductor current reaches the predetermined value, and turns off the transistor when the inductor current reaches the target value.

Abstract: A PFWM control system for a switching-mode power supply (SMPS) circuit including a boost conversion circuit and a DC-DC converter. The PFWM control system includes a duty cycle control unit, a frequency control unit and a PFWM waveform generator module. The duty cycle control unit samples an output voltage or current or power of the DC-DC converter, and calculates a duty cycle of a switching component of the SMPS. The frequency control unit samples an input or output voltage of the boost conversion circuit, and calculates an operation frequency of the switching component. The PFWM waveform generator module synthesizes a PFWM drive signal according to the duty cycle and operation frequency. The PFWM drive signal drives switching component of the boost conversion circuit and the DC-DC converter, so as to control an output voltage, an output current, or an output power provided to a load by the DC-DC converter.

Abstract: The present invention provides a charging system and a charging circuit thereof, including a circuit of a charging apparatus and a circuit of a wireless portable electronic device capable of recognizing an electric connection relationship with the charging apparatus.

Abstract: A switch circuit includes a first switch, a current protection component, a current detection circuit, and a controller. The first switch conducts a primary side coil. The current protection component generates a detection voltage. The current detection circuit outputs a protection voltage. When the detection voltage is not greater than a first threshold, the current detection circuit generates a first voltage corresponding to the detection voltage as the protection voltage. When the detection voltage is greater than the first threshold, the current detection circuit generates a second voltage corresponding to the detection voltage as the protection voltage, where the first voltage is different from the second voltage. The controller is suitable for making the first switch selectively conducting and not conducting. When the protection voltage is greater than a second threshold, the controller does not increase a proportion of a conduction time to a non-conduction time of the first switch.

Abstract: An active clamp switching power converter circuit includes a sensing circuit that generates a sensed auxiliary winding voltage of an auxiliary winding around the core. A primary side controller controls switching of a power switch coupled to a primary winding to control current through the primary winding and controls switching of the active clamp switch based on the sensed voltage to control leakage energy when the power switch is turned off. The primary side controller regulates timing of the switching to achieve a zero voltage switching condition prior to turning on the power switch for power efficient operation.

Abstract: Reverse currents are prevented using existing components, like a primary-side current transformer. A power supply includes an isolation transformer, a switch, a synchronous rectifier, a smoother, a controller with a signal generator circuit that outputs main drive signals for main switching elements of the switch and drive signals for synchronous rectifier elements of the synchronous rectifier, and a current detector that has a current transformer, detects a current flowing to the switch, and outputs an output current detection signal. The controller includes an OR circuit that generates an OR signal for the main drive signals and a reverse current determination circuit that determines whether a reverse current has occurred based on the OR signal and the output current detection signal. When the occurrence of a reverse current has been determined, outputting of the main drive signals and the drive signals is stopped.