Abstract: The present disclosure is directed to a switching power converter having a regulated output voltage or output current. The power converter uses a control unit having a signal conditioning circuit to produce a control voltage signal, which is used to drive a power stage of the converter. The signal conditioning circuit includes a comparator that compares a measured electrical quantity to a reference value representative of a desired regulated output quantity, and produces a digital detection signal based on the comparison. A control actuator uses the digital detection signal to produce a correction signal, which is received by an averaging circuit. The averaging circuit then produces the control voltage signal based on an average of the correction signal.

Abstract: A switching power supply includes: a transformer having a primary coil and a secondary coil; a switching element that is connected in series to the primary coil of the transformer so as to turn a direct-current input voltage applied to the primary coil of the transformer ON and OFF; a rectifying and smoothing circuit that rectifies a voltage induced in the secondary coil of the transformer to generate a direct-current output voltage; and a control circuit that turns the switching element ON and OFF in accordance with the direct-current output voltage, wherein the control circuit includes an input correction circuit that detects a switching period of the switching element and limits a peak value of a current flowing through the switching element in accordance with the detected switching period.

Abstract: A power supply control system includes a remaining level detector 22 of a power-storing device 20; and an estimate computing unit 42 which estimates a prospective power generation of power-generating equipment 10 and a prospective load power consumption of connected loads, and thus, based thereupon and remaining level, a dischargeable time until remaining level reaches the minimum level, and computes an average power generation output of a power-generating equipment 10 and an average load power consumption connected loads 101-105, and thus power generation reaching time until the average power generation output reaches the average load power consumption; and a controller 43 which controls, if the dischargeable time is shorter than the power generation reaching time, to reduce power consumption of the connected loads 101-105.

Abstract: A secondary control circuit includes a voltage regulator circuit coupled to an output of the power converter to provide a regulated power supply. One or more switched loads are coupled between a first terminal and an output ground terminal. The first terminal is coupled to the output of the power converter. Each switched load is coupled to draw a respective current from a load current to clamp the output of a power converter. One or more comparator circuits are coupled to a second terminal. The second terminal is coupled to receive an output sense signal. Each comparator circuit is coupled to receive a reference signal that is a scaled representation of a first reference signal. Each switched load is switched in response to a respective comparator circuit to draw a respective current from the load current of the power converter to clamp the output of the power converter.

Abstract: The power supply apparatus for obtaining a direct current from an alternating voltage source includes a first DC/DC converter for outputting a first direct current and a second DC/DC converter for a second direct current lower than the first direct current from the first DC/DC converter, and the output voltage of the first DC/DC converter is changed to a lower direct current and the second DC/DC converter is driven in a continuously-conducting state.

Abstract: A method of and device for reducing power loss in a voltage conversion circuit. The voltage conversion circuit comprises a main power circuit and a switchable auxiliary circuit, which comprises a first and a second winding circuits. A switch controls the use of the first winding circuit, the second winding circuit, or both to reduce power lose during the voltage conversion.

Abstract: Various arrangements for determining a voltage of a voltage source using pre-charging are presented. Such arrangements may include a measurement module which includes an analog to digital converter, a driver, and an interface. The interface may be electrically coupled with the analog to digital converter and the driver. The driver may be configured to output current to charge a capacitor. After a first predefined period of time, the driver may stop outputting current to pre-charge the capacitor. After the driver has stopped pre-charging the capacitor and a second predefined period of time has elapsed, the analog to digital converter may be configured to measure a voltage of the capacitor. Such arrangements may include a capacitor, wherein the capacitor is electrically coupled with the interface of the measurement module.

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: Converters (1) for supplying pulsed power to light sources (8) comprise switching parts (2) and controlling parts (3) for adapting switching parameters of the switching parts (2) for improving a performance. The switching part (2) may comprise first/second switches (41, 42) that are in first/second modes during a first time interval of a cycle and vice versa during a second time intervals of a cycle. A group of cycles results in a pulse of the pulsed power. A switching parameter such as the first time interval of a first cycle may be shortened to reduce overshoot. A switching parameter such as the second time interval of the first cycle may be shortened or lengthened. A switching parameter such as the second time interval of a last cycle may be lengthened or shortened to reduce overshoot. A third switch (93) for switching the light source (8) is activated and de-activated delayedly to improve transient behavior.

Abstract: A switching power supply apparatus includes a voltage holding unit which holds voltage generated in an auxiliary winding of a transformer, and a voltage detecting unit which detects voltage applied to the first switching unit. When the first switching unit operates such that voltage generated in a secondary winding of the transformer may be low, voltage is supplied from the voltage holding unit to the first switching unit in accordance with the voltage detected by the voltage detecting unit to thus turn on the first switching unit.

Abstract: A main rectifying/smoothing circuit is connected to one end of a secondary winding of a transformer and a plurality of rectifying/smoothing circuits are connected to a plurality of central taps of the secondary winding. The rectifying/smoothing circuits are each equipped with a switch. In a preliminary driving period, a DSP, which controls the switches, reads forward drop voltages of first to third diode loads and sets feedback gains corresponding to the forward drop voltages. The DSP controls the switches based on the set feedback gains and begins rated driving.

Abstract: A hybrid integrated circuit in a wafer level package for an implantable medical device includes one or more passive component windings formed, at least in part, along one or more routing layers of the package. The windings may be primary and secondary windings of a transformer, wherein all or part of a magnetic core thereof is embedded in a component layer of the wafer level package. If the core includes a part bonded to a surface of the package, that part of the core may be E-shaped with legs extending into the routing layers, and, in some cases, through the routing layers. Routing layers may be formed on both sides of the component layer to accommodate the transformer windings, in some instances.

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: The invention concerns a method and device for controlling the switching operation in a switch mode power supply module. The switch mode power supply module is intended to supply power to an item of equipment. The method comprises the steps of measuring, in the switch mode power supply module, the load current and comparing the measured load current with a predefined load current threshold value, and, cyclically interrupting the switching operation if the measured load current inside the device is less than the predefined load current threshold value.

Abstract: Techniques for providing negative current information to a control loop for a buck converter in reverse boost mode. In an aspect, negative as well as positive current through an inductor is sensed and provided to adjust a ramp voltage in the control loop for the buck converter. The techniques may prevent current through the inductor during reverse boost mode from becoming increasingly negative without bound; the techniques thereby reduce settling times when the target output voltage is reduced from a first level to a second level. In an aspect, the negative current sensing may be provided by sensing negative current through a charging, or PMOS, switch of the buck converter. The sensed negative current may be subtracted from a current used to generate the ramp voltage.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter. The switching power converter further comprises a power switch coupled to the primary winding and a rectifier coupled to the secondary winding. Current is generated in the primary winding responsive to the power switch being turned on and not generated responsive to the power switch being turned off. A detection circuit measures a voltage across the rectifier. If the detection circuit detects a decrease in the voltage across the rectifier outside of a blanking period, the detection circuit generates a current pulse in the secondary winding of the transformer. A fast power-on-reset device generates a startup signal to activate the detection circuit at an end of the blanking period.

Abstract: When a detection voltage VCS that corresponds to a voltage drop across a detection resistor RCS exceeds a first threshold value VADIM, a current limit comparator asserts a reset pulse. A zero current detection circuit asserts a set pulse configured as an instruction to turn on a switching transistor. A logic circuit generates a control pulse based on the reset pulse and the set pulse. When a transition occurs in a dimming pulse from an on level to an off level in a period in which the control pulse is set to the on level, the dimming pulse adjusting unit delays this transition to a next off period of the control pulse.

Abstract: On embodiment of a device with a noise adaptive power supply includes a noise adaptation unit configured to receive a noise adaptation signal. The noise adaptation unit can provide processing, such as digital filter processing to reduce the effect of power supply noise. In one embodiment, a feedback signal is used to adjust the output voltage of the power supply. The noise adaptation signal can be similar to the feedback signal. The noise adaptation unit can provide the processing in response to the noise adaptation signal.

Abstract: A PWM module is provided to output a driving pulse to a switching device in synchronization with a synchronizing pulse having a frequency twice the frequency of the high-frequency current of a primary-side induction line. The PWM module performs output voltage feedback control such that the output voltage of an output capacitor is set at a reference voltage. The module outputs, to the switching device, the driving pulse having a half width of the pulse width of a driving pulse that can be outputted, at the start of power supply to the primary-side induction line. Moreover, the module forcibly performs the output voltage feedback control if an output voltage of the output capacitor does not increase to the reference voltage within a reference time.

Abstract: An intrinsic piezoelectric transformer circuit a piezoelectric transformer circuit is provided that has a primary side component including first and second electrodes, a secondary side component including first and second electrodes, and at least one tertiary component including first and second electrodes. A power bridge is provided which includes one or more switches, each switch has a gate terminal that is directly connected to the second electrode of the tertiary component of the piezoelectric transformer. The first electrode of the tertiary component of the piezoelectric transformer is connected to a reference for the one or more switches of the power bridge. The first electrode of the primary component of the piezoelectric transformer is electrically connected to a power bridge output and the second electrode of the primary component of the piezoelectric transformer is connected to a ground terminal.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A switch-mode power supply control apparatus includes a PWM controller for outputting a driving signal and a short-circuit protection module coupled to a detection terminal. The detection terminal receives a zero-crossing detection voltage. If the time that the detection voltage input to the detection terminal is lower than a first reference voltage exceeds a predetermined time period, the short-circuit protection module determines that a short-circuit abnormal situation occurs, the short-circuit protection module outputs a short-circuit signal to the PWM controller, and the driving signal output by the PWM controller becomes a turn-off signal. If the short-circuit protection module does not detect the short-circuit abnormal situation, the PWM controller operates normally. A flyback switch-mode power supply includes the switch-mode power supply control apparatus. The flyback switch-mode power supply has a low power consumption when a short-circuit protection is taking place.

Abstract: In one embodiment, an apparatus includes a clock generator to generate differential clock signals. The apparatus also includes a distributed polyphase filter to obtain phase-corrected multi-phase clock signals based on the differential clock signals.

Abstract: An inverter device includes a switching device which performs on-off switching of an input voltage, a step-up transformer which applies an excitation current to its winding during a switching-device-on period and outputs an output voltage during a switching-device-off period, an input-voltage detector which detects the input voltage and output an input-voltage detection signal, an output voltage detector which detects the output voltage and output an output-voltage detection signal, an output-produced-period detector which detects a period when the output voltage is produced based on the output-voltage detection signal, a comparator which detects a period when the output-voltage detection signal exceeds the input-voltage detection signal and output information indicating the output-high period, and a shifting unit which shifts the information indicating the output-high period to a next period when absence of the output produced period is detected.

Abstract: A power supply circuit (1) including: rectifying and smoothing circuit (31); transistor (switching element) (37) connected to an output terminal of the rectifying and smoothing circuit (31); transformer (TF1) including primary coil (L36) connected to the transistor (37) and secondary coil (L47) magnetically coupled with the primary coil (L36); current detector circuit (41) detecting current flowing through the transistor (37), and outputting voltage corresponding to the current; voltage output circuit (44) outputting, while the transistor (37) is in a turned-on state, voltage dependent on voltage induced by the secondary coil (L47); and on-off control circuit (57) turning off the transistor (37) when absolute value (Vbe) of a difference between the voltage from the current detector circuit (41) and the voltage from the voltage output circuit (44) is no smaller than threshold voltage (Von), and turning on the transistor (37) when the absolute value (Vbe) is smaller than the threshold voltage (Von).

Abstract: In a switching power supply apparatus, a main switching control circuit performs switching control of a low-side switch device and a high-side switch device based on a feedback signal corresponding to a main output voltage output from a secondary winding of a transformer, and applies and stops applying a voltage to a primary winding of the transformer. A digital signal processor, in accordance with the load status of the main load, changes set target values, performs switching control of switch devices of the sub-rectifying and smoothing circuits, and drives sub-loads.

Abstract: In a switching power supply apparatus, a low-side switching device is connected in series with a primary winding. A high-side switching device and the primary winding define a closed loop. A voltage induced in a high-side drive winding is applied to the high-side switching device to turn on the high-side switching device. A transistor, which is turned on/off in accordance with the voltage across a capacitor charged by the voltage induced in the high-side drive winding, is connected to the gate terminal of the high-side switching device. When the capacitor is charged and the transistor is turned on, the high-side switching device is turned off. The capacitor is discharged by the voltage induced in the high-side drive winding, during the ON period of the low-side switching device.

Abstract: A drive circuit for a switching element includes a constant-current control unit and a restriction unit. The constant-current control unit performs a constant-current control for charging an open/close control terminal of a switching element to be driven which is a voltage-controlled switching element with electric charge for turning on the switching element. The restriction unit restricts, to a reference voltage, a voltage between the open/close control terminal and a first end of a pair of ends of a current flow path of the switching element for a predetermined period following a start of the constant-current control within a charging process period during which the open/close control terminal is charged with the electric charge such that the switching element is turned on.

Abstract: A switched mode power supply (SMPS) includes a transformer with a primary winding, a secondary winding, an auxiliary winding, and a power switch coupled to the primary winding. During one switching cycle, the auxiliary winding provides a feedback signal which includes a first voltage pulse that is induced after the power switch is turned on and a second voltage pulse that is induced after the power switch is turned off. A control circuit includes a circuit for generating a sampling signal for sampling the second voltage pulse in a switching cycle at a time that is determined based on the first voltage pulse in the same switching cycle. A sample-and-hold circuit is configured for sampling and storing the second voltage pulse in response to the sampling signal. A switching signal generating circuit is configured to generate a switching signal for controlling the power switch based on an output of the sample-and-hold circuit.

Abstract: The present invention provides a switched-mode power converter with regulation demand pulses sent across a galvanic isolation barrier.

Abstract: A low let-through voltage surge suppression or protection circuit for protecting hardware or equipment from electrical surges. During operation when no surge condition is present, the circuit allows propagation of signals from a source to a load along a signal path. When a surge is present, the circuit senses and diverts the surge away from the signal path, utilizing common mode and/or differential mode surge protection. An electronic filter is connected in parallel with surge suppression circuit elements for reducing the let through voltage that would otherwise propagate and require a higher power surge suppression circuit element to mitigate. Cascading multiple electronic filters in parallel with surge suppression circuit elements further reduces voltage let through.

Abstract: A multilevel DC-DC converter includes a voltage source that provides a voltage Vout1 to at least one charge converter circuit and an output filter capacitor having an associated output voltage Vout2. The at least one charge converter circuit includes a transformer having at least one primary winding and at least two secondary windings, a primary and secondary circuit each having at least two switching elements, and a control unit which receives a control signal, such as but not limited to an envelope tracking signal, which represents a desired output voltage. The control unit is arranged to provide output control signals to the respective switching elements of the primary and secondary circuits to activate and deactivate the respective switching elements to obtain a desired output voltage Vout2. The multilevel DC-DC converter can be arranged to operate as a boost converter or as a buck-boost converter.

Abstract: A controller integrated circuit (IC) for controlling a power converter uses one or more IC pins having plurality of functions such as configuration of a parameter supported by the controller IC and shutdown protection. Several different functions may be supported by a single IC pin, thereby reducing the number of pins required in the controller IC and also reducing the cost of manufacturing the controller IC. The controller IC may also share a comparison circuit among different pins and the different functions provided by those pins. Use of a shared comparison circuit further reduces the cost of manufacturing the controller IC without sacrificing the performance of the IC.

Abstract: An electrostatic induction conversion device includes: an input-side electrostatic actuator that includes a first fixed electrode and a first movable electrode facing the first fixed electrode; and an output-side electrostatic actuator that includes a second movable electrode linked to the first movable electrode via a link mechanism member, which increases or decreases a displacement quantity representing an extent of displacement occurring at the first movable electrode, and a second fixed electrode facing the second movable electrode, wherein: a permanently charged layer is deposited on an electrode surface either on a movable electrode side or on a fixed electrode side, at the input-side electrostatic actuator and the output-side electrostatic actuator.

Abstract: A dimmable LED driver adapted to be operated with a dimmer that is configured to generate a predetermined conductive angle, wherein the dimmable LED driver comprises: a rectifier configured to convert an alternating current output by the dimmer to a direct current, a buck PFC block configured to adjust an output voltage of the direct current so as to obtain a stable output voltage, a second buck DC/DC block configured to realize output of a constant current after the stable output voltage is realized, a dimming block configured to, after realizing output of the constant current, accomplish a dimming function jointly with the second buck DC/DC block, and an MCU configured to control the buck PFC block, the second buck DC/DC block and the dimming block.

Abstract: Disclosed is a circuit arrangement for determining a temporal change of an output voltage of a half-bridge circuit during a dead time. In one embodiment, the circuit arrangement includes a first input for applying the output voltage. A capacitive network includes a first and a second circuit node capacitively coupled to the input, and having a terminal for a reference potential. A recharging circuit during the switched-on phase of one of a first and second switching elements, adjusts electrical potentials of the first and second nodes, the electrical potentials each being different from the reference potential. A comparator arrangement, during the dead time, determines a time difference between such times at which the electrical potentials at the first and second node each assume a given potential value, the time difference being a measure for the change with time of the output voltage.

Abstract: Various arrangements for determining a voltage of a voltage source using pre-charging are presented. Such arrangements may include a measurement module which includes an analog to digital converter, a driver, and an interface. The interface may be electrically coupled with the analog to digital converter and the driver. The driver may be configured to output current to charge a capacitor. After a first predefined period of time, the driver may stop outputting current to pre-charge the capacitor. After the driver has stopped pre-charging the capacitor and a second predefined period of time has elapsed, the analog to digital converter may be configured to measure a voltage of the capacitor. Such arrangements may include a capacitor, wherein the capacitor is electrically coupled with the interface of the measurement module.

Abstract: A DC power supply (1) having a series regulator (2) for generating a fixed output DC voltage (VCC) at a variable input AC voltage (VAC) with low power loss. For this purpose, the DC power supply (1, 101, 201, 301) has a transformer (3, 103) having at least two auxiliary windings (W1, W2) having different numbers of windings that can each be connected via a switching device (4, 104, 204, 304) to the series regulator (2). Switching is effected such that the power loss is kept as low as possible.

Abstract: Disclosed is a dual-source converter for a hybrid power supply. The converter includes a first power circuit, a second power circuit, an auxiliary circuit, an output circuit and a closed loop circuit. The first power circuit is electrically connected to the second power circuit in series for receiving two varied voltage sources. The auxiliary circuit is configured to achieve soft switching of all switches. The closed loop circuit is configured to control the duty cycles of the first power circuit, the second power circuit and the auxiliary circuit so as to improve the efficiency of the dual-source converter.

Abstract: Described are improvements in power factor control and systems embodying said improved power factor control. Improvements lie in a method of zero voltage switching in which a capacitor is placed in parallel with a switching device, and the switching device is operated responsive to a change in the polarity of the current through the capacitor. Switching therefore occurs at zero or close to zero voltage across the switching device in both on and off modes resulting in very low switching losses and electromagnetic interference. Systems employing the method include a power factor controller, LED light source, boost converter and a power source comprising one or more photovoltaic cells.

Abstract: An object of the invention is to accurately detect a state of an object to be heated in a cooking vessel and effectively avoid cooking failure. An induction heating section (13) inductively heats a cooking vessel (11). A vibration detecting section (14) detects a vibration of the cooking vessel (11) via a top plate (12). A vibration waveform extracting section (15) extracts a vibration waveform of a frequency component having a frequency equal to a predetermined multiplication product of an induction heating frequency, from a waveform of the vibration detected by the vibration detecting section (14). A determining section (16) determines a state of an object to be heated, based on the vibration waveform extracted by the vibration waveform extracting section (15).

Abstract: LED dimming control circuit and method compensate LED current or LED average current by LED characteristics to improve dimming efficiency and performance. LED characteristic related look-up tables are stored to provide compensation values, and input LED current setting information is compensated by the compensation values to generate corrected LED current setting information for determining LED brightness.

Abstract: A switching power-supply apparatus includes: a control circuit that controls on-and-off switching of a switching element; a first rectifying-and-smoothing circuit that smoothes a voltage generated in a secondary winding; and a second rectifying-and-smoothing circuit that smoothes a voltage generated in a tertiary winding as a power supply voltage, a starting circuit that supplies: a first constant current to the control circuit when the power supply voltage is equal to or lower than a first threshold voltage, which is lower than a starting voltage of the control circuit, and is larger than the starting voltage of the control circuit, as a starting current; and a second constant current, which is greater than the first constant current, to the control circuit when the power supply voltage is larger than the first threshold voltage and is equal to or lower than the starting voltage, as the starting current.

Abstract: Consistent with example embodiments disclosed, there are switched-mode power supplies (SMPS) in which a signaling capacitor transmits information across a transformer of the power supply. Such embodiments can avoid drawing power from the output capacitor in order to provide communication signals and so do not cause a drop in the output voltage when signaling to the primary side. Further, the switched mode power supply can send signals from the secondary side of the transformer to the primary side via the transformer itself and so may not require the incorporation of an opto-coupler. Such embodiments may reduce production costs, the printed circuit board (PCB) footprint and reduce the no-load power consumption of the SMPS.

Abstract: According to one embodiment, a nitride semiconductor device includes a semiconductor layer, a source electrode, a drain electrode, a first and a second gate electrode. The semiconductor layer includes a nitride semiconductor. The source electrode provided on a major surface of the layer forms ohmic contact with the layer. The drain electrode provided on the major surface forms ohmic contact with the layer and is separated from the source electrode. The first gate electrode is provided on the major surface between the source and drain electrodes. The second gate electrode is provided on the major surface between the source and first gate electrodes. When a potential difference between the source and first gate electrodes is 0 volts, a portion of the layer under the first gate electrode is conductive. The first gate electrode is configured to switch a constant current according to a voltage applied to the second gate electrode.

Abstract: A switching power supply device that includes a feedback terminal to which a feedback signal according to a load state is input, and a comparator which compares a terminal voltage of the feedback terminal with a reference voltage and determines whether the load state is a normal load state or a light load state. The switching power supply device also includes pull-up resistors which are connected to the feedback terminal, a switch element which switches resistance values of the pull-up resistors according to the change of the load state, and a switch element which switches the resistance values of the pull-up resistors according to whether the input voltage is high or low.

Abstract: Improving start-up time of a light emitting diode (led) driver at lower input voltage is accomplished with a quick start circuit comprising a constant current source that replaces the traditional trickle charge start-up path for charging of a Vcc capacitor supplying operating voltage to an SMPS controller. Also the constant current source will only be operational during SMPS start-up, then will turn off after the SMPS is capable of producing its own regulated power supply to the Vcc terminal of the SMPS controller, thereby minimizing E2/R power losses in the SMPS.

Abstract: A switching power supply apparatus includes a low-side switching control unit and a high-side switching control unit. The low-side switching control unit includes a low-side turn-off circuit that turns off a low-side switching element behind a delay time when reversal of the polarity of a winding voltage of a transformer is detected during a period in which a drive voltage signal is supplied to the low-side switching element. The high-side switching control unit includes a high-side turn-on delay circuit that delays a time from the time when the polarity of the winding voltage of the transformer is reversed to a time when a high-side switching element is turned on. The delay time of the low-side turn-off delay circuit is set so as to be shorter than the delay time of the high-side turn-on delay circuit.

Abstract: A switching control IC conducts on-off control on a first switching element. A second switching control circuit is provided between a high-side driving winding of a transformer T and a second switching element. The second switching control circuit discharges a capacitor in a negative direction with a constant current during an on period of the first switching element, and then after the second switching element is turned on, charges the capacitor in a positive direction with a constant current. A transistor controls the on period of the second switching element in accordance with the ratio of a charging current to a discharge current such that the ratio of the on period of the second switching element to the on period of the first switching element is substantially always constant.

Abstract: An example control element for use in a power supply includes a high-voltage transistor and a control circuit to control switching of the high-voltage transistor. The high-voltage transistor includes a drain region, source region, tap region, drift region, and tap drift region, all of a first conductivity type. The transistor also includes a body region of a second conductivity type. An insulated gate is included in the transistor such that when the insulated gate is biased a channel is formed across the body region to form a conduction path between the source region and the drift region. A voltage at the tap region with respect to the source region is substantially constant and less than a voltage at the drain region with respect to the source region in response to the voltage at the drain region exceeding a pinch off voltage.