Abstract: A power converter incorporating a synchronous rectifier implements adaptive gate voltage regulation for fast turn-off of the synchronous rectifier. In some embodiments, the adaptive gate voltage regulation circuit and method monitors the slope of the synchronous rectifier current during the on period of the synchronous rectifier. In response to detecting the synchronous rectifier current decreasing rapidly, a larger gate discharge current is applied to quickly discharge the synchronous rectifier gate voltage. In response to detecting the synchronous rectifier current decreasing more moderately, a smaller gate discharge current is applied to discharge the synchronous rectifier gate voltage in a moderate manner. When the synchronous rectifier can be turned off quickly, large reverse current and large drain voltage spike at the synchronous rectifier is avoided. The adaptive gate voltage regulation circuit and method is particularly useful when the power converter is operated in the discontinuous conduction mode.

Abstract: Controlling an active clamp field effect transistor (FET) and a primary-side FET in a secondary-controlled active clamp converter is described. In one embodiment, an apparatus includes a primary-side FET coupled to a transformer and an active clamp FET disposed on a primary side of the transformer. A secondary-side controller is configured to control the active clamp FET and the primary-side FET across a same galvanic isolation barrier.

Abstract: An embodiment converter includes a magnetic material, a first circuit including a first winding surrounding the magnetic material and a clamp circuit configured to reset a power conversion operation, the first circuit being configured to convert power received from a first input voltage source to provide the converted power to a load, and a second circuit including a second winding surrounding the magnetic material, the second circuit being configured to convert power received from a second input voltage source to provide the converted power to the load and to perform the power conversion operation being reset by the clamp circuit.

Abstract: A power converter-circuit (100) having a transformer (T), comprising a snubber-circuit (Csn, DSn,S3, S3, DSn,S4) for suppressing voltage peaks on a secondary side of the transformer (T) that comprises a snubber capacitor (Csn); and an auxiliary DC-DC converter (101) having a first input connected with the snubber capacitor (Csn) and a first output connected with a first output (VOut) of the power converter-circuit (100). This circuit increases efficiency of electrical conversion and reduces thermal losses.

Abstract: A low-dropout linear regulator regulates a supply voltage and includes a voltage-to-frequency circuit producing a pulse chain with a frequency based on an error voltage. A charge pump circuit receives the pulse chain and switching one or more charge pumps based on the pulse chain. A current mirror circuit is connected to the charge pump circuit and includes a first diode-connected metal-oxide semiconductor (MOS) transistor, and a second MOS transistor having a first terminal connected to the supply voltage, a second terminal providing an output, and a gate connected to the gate of the first MOS transistor. The output is fed back to the voltage-to-frequency circuit.

Abstract: An electronic device has a primary loop circuit that includes a main circuit causing a current to flow in a loop shape; and a secondary loop circuit that is disposed to face the primary loop circuit at a predetermined distance, and causes an induced current generated by a magnetic field generated in the primary loop circuit to flow in a loop shape.

Abstract: Power converter electronic circuitries configured to harvest and store energy from at least the parasitic oscillation occurring during the operation thereof. Methodologies of using such energy for the current injection, carried out by discharging the parasitic capacitance across the switching elements to achieve zero voltage switching condition for these switching elements. In a specific case, the methodology of current injection (with the use of so harvested and stored energy) is self-adjusting, causing the optimization of the energy required to discharge the parasitic capacitance.

Abstract: The subject application provides a power converter with lossless current sensing capability. The power converter comprises: a transformer, a primary switch for conducting or blocking a current flowing in a primary winding of the transformer, a controller configured to generate a first control signal through a first control node to control the primary switch; and a current sensing circuit configured for sensing a current flowing in the primary winding. The current sensing circuit comprises a current sensing switch that is configured to be normally open and has a gate length smaller than a gate length of the primary switch. A relatively simple current sensing circuit is achieved and the overall power efficiency is improved.

Abstract: A secondary controller for use in a power converter includes a drive circuit coupled to a secondary side of the power converter. The drive circuit is configured to generate a first signal to enable a first switch coupled to a primary side of the primary converter. The first signal is generated in response to a feedback signal representative of an output of the power converter. A control circuit is coupled to receive the first signal and an input signal representative of a secondary winding voltage of the power converter. The control circuit is configured to generate a second signal to control a second switch coupled to the secondary side of the power converter. The control circuit is configured to generate the second signal in response to the first signal and a compare signal, and in response to an output of a latch.

Abstract: An apparatus including a bidirectional power converter circuit. The power converter circuit includes a primary circuit side including a plurality of primary switches, an isolation transformer, and a secondary circuit side separated from the primary circuit side by the isolation transformer. The secondary circuit side includes an inductor, a rectifier circuit coupled to the inductor and configured to receive energy from the primary circuit side and provide energy to the primary circuit side, and a clamp circuit coupled to the inductor and configured to provide a reset voltage to the inductor that prevents inductor current runaway.

Abstract: A deadtime control scheme for improving buck converter light load efficiency.

Abstract: A control circuit is configured to control a flyback circuit comprising a primary-side switch, a secondary-side rectifier and a transformer. The control circuit comprises a feedback control circuit configured to generate a secondary-side control signal based on a current ripple signal of the transformer, and at least one of a direct-current component of an output voltage signal and a direct-current component of an output current signal of a secondary side of the flyback circuit, wherein the secondary-side control signal is configured to control a turn-off of the secondary-side rectifier, an isolated transmission circuit coupled to the feedback control circuit and configured to generate a first primary-side control signal based on the secondary-side control signal, and a primary control circuit coupled to the isolated transmission circuit and configured to control a turn-on of the primary-side switch in response to receiving the first primary-side control signal.

Abstract: A transient current in a rectifier circuit is effectively reduced. In a rectifier circuit, a first rectifier is provided between a first terminal and a second terminal. In the rectifier circuit, when a switch element is turned ON, a primary winding current flows from a power supply to a primary winding of a transformer. When the switch element is turned OFF, a second rectifier current flows from a secondary winding of the transformer to a second rectifier. During a period in which the second rectifier current is flowing, a reverse voltage is applied between the first terminal and the second terminal.

Abstract: A zero-voltage-switching control circuit for a switching power supply having a main power switch and a synchronous rectifier switch, is configured to: control the synchronous rectifier switch to be turned on for a first time period before the main power switch is turned on and after a current flowing through the synchronous rectifier switch is decreased to zero according to a switching operation of the main power switch in a previous switching period of the main power switch; and where a drain-source voltage of the main power switch is decreased when the main power switch is turned on, in order to reduce conduction loss.

Abstract: A synchronous rectifier control apparatus includes a continuous conduction mode detection circuit configured to receive a voltage across a synchronous rectifier switch and determine whether the synchronous rectifier switch operates in a continuous conduction mode based on a rising slope of the voltage across the synchronous rectifier switch, a turn-off timer control circuit configured to measure a conduction time of the synchronous rectifier switch and turn off the synchronous rectifier switch after the conduction time of the synchronous rectifier switch in a current cycle is substantially equal to the conduction time measured in an immediately previous cycle, and a drive voltage control circuit configured to reduce a gate drive voltage of the synchronous rectifier switch after the conduction time of the synchronous rectifier switch in the current cycle is substantially equal to the conduction time measured in the immediately previous cycle multiplied by a predetermined percentage.

Abstract: A system for turning off a synchronous rectifier (SR) based on a primary switch (PS) turn-on detection in a flyback converter having a primary-side and a secondary-side is disclosed. The system comprises the PS on the primary-side, the SR on the secondary-side, a spike detector, and a SR controller. The SR is configured to produce a drain-to-source voltage (VDS). The spike detector is in signal communication with an output capacitor (Cout) on the secondary-side and the spike detector is configured to detect a voltage spike of an output voltage (VOut) across the Cout that is indicative of the PS being turned-on. The SR controller is in signal communication with the SR and the spike detector and the SR controller is configured to turn-off the SR based on the spike detector detecting the voltage spike of the VOut.

Abstract: A power converter includes a primary winding and multiple output windings to provide multiple independently controlled and regulated outputs with a common return line. The outputs are coupled to independently regulate constant current, constant voltage, or both constant current and constant voltage outputs. A secondary control block is coupled to control a synchronous rectifier switch coupled to the common return line to synchronize switching with a primary side power switch to provide complementary conduction of the primary winding and the multiple output windings. A plurality of controlled power pulse switches is coupled to the multiple output windings. A request of a power pulse from each of the outputs is transferred through the secondary control block to a primary switch control block to turn on the primary side power switch to transfer a power pulse to the multiple output windings and through controlled power pulse switches to the outputs.

Abstract: Described herein are apparatuses and methods for applying high voltage, sub-microsecond (e.g., nanosecond range) pulsed output to a biological material, e.g., tissues, cells, etc., using a high voltage (e.g., MOSFET) gate driver circuit having a high voltage isolation and a low inductance. In particular, described herein are multi-core pulse transformers comprising independent transformer cores arranged in parallel on opposite sides of a substrate. The transformer cores may have coaxial primary and secondary windings. Also describe are pulse generators including multi-core pulse transformers arranged in parallel (e.g., on opposite sides of a PCB) to reduce MOSFET driver gate inductance.

Abstract: Techniques involve: if it is determined that a power supply level of a processing unit in a normal mode in a computer system is lower than a threshold level, determining the remaining power of a battery backup unit in the computer system; and if it is determined that the remaining power is higher than the threshold power, causing the battery backup unit to supply power to the processing unit to maintain the processing unit in the normal mode. Accordingly, the performance of the computer system can be optimized and stabilized without increasing the hardware cost of the computer system or changing the power supply capability of the computer system, and the user experience of users using the computer system can be improved.

Abstract: A control method includes the steps of: setting first control periods of a switching transistor group, the first control periods including operating periods in the first driving mode and operating periods in the second driving mode; setting an output voltage and a K value in a directly proportional relationship, wherein the K value is the ratio of the number of the operating periods in the second driving mode to the number of the operating periods in the first driving mode; receiving the output voltage, and determining a K value corresponding to the existing output voltage according to the set relationship between the output voltage and the K value; and outputting a driving signal group of the switching transistor group according to the number of the operating periods in the first driving mode and the number of the operating periods in the second driving mode.

Abstract: A control circuit for controlling a synchronous rectification switch of a resonant converter, where in a switching cycle, the control circuit is configured to: delay a first time period from a first moment; control the synchronous rectification switch to be turned on when a drain-source voltage of the synchronous rectification switch reaches a first threshold after the first time period; and where the first time period is generated based on an operating state of the synchronous rectification switch in a previous switching cycle.

Abstract: A converter includes an input capacitor, a primary-side switch circuit, a magnetic element circuit, a secondary-side switch circuit, and an output capacitor. The magnetic element circuit includes a transformer and an inductor. The input capacitor is configured to receive an input voltage. The primary-side switch circuit is coupled to the input capacitor. The magnetic element circuit is coupled to the primary-side switch circuit. The inductor is a leakage inductor of the transformer or an external inductor coupled between the transformer and the primary-side switch circuit. The secondary-side switch circuit is coupled to the magnetic element circuit. The output capacitor is coupled to the secondary-side switch circuit. The input capacitor and the inductor generate an oscillating current. The primary-side switch circuit is switched at an adjacent region of a wave trough of the oscillating current.

Abstract: A voltage regulator can include: N energy storage capacitors, each having first nodes connected together, where N is a positive integer; N input capacitors connected in series between two nodes of an input port; N input switch circuits, each being connected in parallel with a corresponding one of the N input capacitors, where each of the N input switch circuits is configured to selectively couple a second node of a corresponding one of the N energy storage capacitors to a first node or a second node of the corresponding input capacitor; and a first output switch circuit configured to selectively couple the first nodes of the N energy storage capacitors to a first node or a second node of an output port.

Abstract: A driving circuit for driving a synchronous rectifier device. The driving circuit may include a controllable clamping circuit having a first terminal coupled to a sensing terminal of the driving circuit, a second terminal coupled to a reference ground terminal of the driving circuit, a third terminal coupled to a driving terminal of the driving circuit, and a control terminal configured to receive a supply indication signal indicative of a voltage potential at a supply terminal of the driving circuit. The third terminal of the controllable clamping circuit may be connected to the second terminal of the controllable clamping circuit when the supply indication signal indicates that the voltage potential at the supply terminal has not been established to maintain the synchronous rectifier device off.

Abstract: A bipolar current control drive circuit for an inductive load includes a switching power supply circuit in which an alternating current from a power supply is formed to a direct current smoothed through a rectifier bridge diode and a primary smoothing capacitor, the current is transmitted to a secondary side using a switching transformer, and the current is formed to a direct current. The switching transformer includes a first secondary coil and a second secondary coil for one primary coil to form alternating currents from the secondary coils to direct currents in reverse orientations and output the currents to an inductive load. A polarity control circuit controls switching between closing and opening of a first secondary switching element and a second secondary switching element and controls the polarity of an electric current.

Abstract: A control system for synchronous rectifying transistor of LLC converter, the system comprising a voltage sampling circuit, a high-pass filtering circuit, a PI compensation and effective value detection circuit, and a control system taking a microcontroller (MCU) as a core. When the LLC converter is operating at a high frequency, a drain-source voltage VDS(SR) of the synchronous rectifying transistor delivers, via the sampling circuit, a change signal of the drain-source voltage during turn-off into the high-pass filtering circuit and the PI compensation and effective value detection circuit to obtain an effective value amplification signal of a drain-source voltage oscillation signal caused by parasitic parameters, and the current value is compared with a previously collected value via a control circuit taking a microcontroller (MCU) as a core, so as to change a turning-on time of the synchronous rectifying transistor in the next period.

Abstract: An electronic device having multiple power output circuits that individually include a switch control input, a bypass control input, an output transistor and an output control circuit that includes an RC circuit with a resistor and a capacitor coupled to the output transistor gate and a bypass switch in parallel with the RC circuit resistor. The electronic device includes a controller that selects one of the power output circuits for a given power transfer cycle, closes the bypass switch to bypass the resistor of the selected power output circuit and turns the output transistor of the selected power output circuit on to transfer current from the inductor to a load of the selected power output circuit.

Abstract: A switching power supply includes an input terminal and an output terminal, a voltage converter including a first switching circuit configured to serve as a trigger for inputting a voltage from the input terminal and a second switching circuit configured to serve as a trigger for outputting, after the input voltage is converted, the converted voltage from the output terminal O, a control circuit configured to output a control signal for selectively sequentially driving the first switching circuit and the second switching circuit, and a delay circuit configured to delay, based on the control signal for driving any one of the first switching circuit and the second switching circuit, a subsequent driving timing of the other switching circuit that is not driven to provide a dead time when both the first switching circuit and the second switching circuit are turned off.

Abstract: Synchronous rectification methods and algorithms, and polarity sensing techniques, based on the homopolarity cycle concept for conduction loss reduction in LLC resonant converters are provided. In a half bridge rectifier configuration, one of rectifier switches is switched ON when the polarity of the inverter and rectifier voltages are both positive and the other rectifier switch is switched ON when both polarities are negative.

Abstract: An AC-DC converter with synchronous rectifier (SR) architecture and method for operating the same are described. Generally, a secondary side integrated circuit (IC) controller of the AC-DC converter includes a SR-SNS pin, a VBUS_IN pin, a first voltage-to-current converter, a sample-and-hold (S/H) circuit, a second voltage-to-current converter, and a signal generation circuit. The first voltage-to-current converter is coupled to remove a component of the output bus voltage sensed on the VBUS_IN pin from the voltage sensed on the SR-SNS pin. The S/H circuit is coupled to sample the voltage sensed on the SR-SNS pin and to provide a sampled voltage. The second voltage-to-current converter is coupled to convert the sampled voltage to a feed-forward current. The signal generation circuit is coupled to receive the feed-forward current and to generate feed-forward signals used to control operation of a primary side of the AC-DC converter.

Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: An active clamp circuit includes an active clamp capacitor coupled in series with an active clamp switch and an active clamp controller circuit to receive an active clamp switch current that passes through the active clamp switch and to control the active clamp switch based on the received active clamp switch current. The active clamp controller circuit is configured to enable the active clamp switch based on a first amplitude comparison, the first amplitude comparison being based on the active clamp switch current. The active clamp controller circuit is configured to disable the active clamp switch based on a second amplitude comparison and a third amplitude comparison, the second amplitude comparison and the third amplitude comparison being based on the active clamp switch current.

Abstract: A DC/DC converter includes: a first capacitor and a second capacitor coupled to a first node; a five-port network coupled to the first to fifth nodes; a transformer electrically connected to the fourth and fifth nodes; and a secondary side circuit electrically connected to a secondary winding of the transformer and coupled to a load; the control method includes: controlling, when the load is less than a preset value, switching states of multiple switches in the secondary side circuit, causing the transformer to be short-circuited for at least a first time period during a phase of stopping energy transmission; and controlling switching states of multiple switches in the five-port network during the first time period, causing current to flow from the five-port network to the first node or flow from the first node to the five-port network.

Abstract: A synchronous rectifier control circuit includes a drain voltage input, a first gate voltage output, a second gate voltage output, a gate voltage generation circuit, and a trigger control circuit. The gate voltage generation circuit includes a first input coupled to the drain voltage input, and an output coupled to the first gate voltage output. The trigger control circuit includes a first input coupled to the first gate voltage output, a second input coupled to the second gate voltage output, and an output coupled to a second input of the gate voltage generation circuit.

Abstract: A secondary-side controller for an AC-DC converter that has a single synchronous rectifier sensing (SR_SNS) terminal, coupled to a synchronous rectifier (SR) of the AC-DC converter, and a voltage divider circuit coupled to the single SR_SNS terminal configured to provide signals to a sensing circuit. The voltage divider includes an active diode, an internal resistive element, and a switch, in which the active diode is configured to control the switch to enable or disable the internal resistive element based on a comparison result of a voltage at the single SR_SNS terminal and a reference voltage.

Abstract: A method of operating a converter includes: charging an LC tank coupled between a switching network and a primary winding of a transformer for a first period of time by connecting the LC tank to one or more input capacitors via the switching network, where the switching network includes a first half-bridge coupled between a first supply terminal and a center node, and a second half-bridge coupled between the center node and a second supply terminal; preventing energy transfer from the primary winding of the transformer to a secondary winding of the transformer during the charging of the LC tank; and after charging the LC tank, discharging the LC tank for a second period of time by disconnecting a terminal of the LC tank from the one or more input capacitors.

Abstract: A synchronous rectifier controller method is provided for controlling the on and off periods of a synchronous rectifier (SR) switch transistor in a switching power converter. The method includes a first step of monitoring an unfiltered to control whether the SR switch transistor is turned on during a first part of a power switch cycle. The method also includes a second step of monitoring a filtered SR switch signal to control whether the SR switch is turned on during a remaining second part of the power switch cycle.

Abstract: In this invention we introduce the concept of a soft switching half bridge switching cell wherein the soft switching is guaranteed by the magnetizing current. Further this soft switching half bridge cell contains at least two synchronous rectifiers in the secondary which are conducting together during the dead time of the primary switchers creating a short circuit across the secondary windings, trapping the magnetizing current and release the magnetizing current to discharge the parasitic capacitances across the primary switchers when the synchronous rectifiers turn off. The secondary windings are connected to a synchronized and controlled current source.

Abstract: A DC-DC converter can include: a switched capacitor converter including at least one switch group and at least one capacitor, where each of the at least one switch group includes two switches are coupled in series, and at least one of the capacitors is coupled in parallel with a corresponding one of the switch groups; and at least one switch converter, where each switch converter includes at least one primary magnetic circuit and is configured to share at least one of the switch groups, one terminal of the primary magnetic circuit is coupled to an intermediate node of the shared switch group, the intermediate node is a common coupling point of two switches of the shared switch group, and the switch converter is an unidirectional power converter.

Abstract: A secondary side controller for an AC-DC converter and method for operating the same are provided. Generally, the controller includes a single synchronous rectifier sense (SR-SNS) pin coupled to a drain of a SR on a secondary of a transformer to sense a voltage (VSRD). In feed-forward (FF) mode VSRD is a sum of a voltage (VIN) on a primary divided by a turn-ratio (N) of the transformer and an output bus voltage (VBUS). A voltage-to-current (V2I) converter coupled to the SR-SNS pin and to the output bus removes VBUS from VSRD. A sample and hold (S/H) module coupled to the SR-SNS pin samples a voltage (VSAMP) including information on VIN/N. A VIN/N V2I converter coupled to the S/H module converts VSAMP to a feed-forward current (IFF), and a cancellation and signal module coupled thereto extracts information on VIN from IFF and generates signals to control the AC-DC converter.

Abstract: Whether a synchronous signal includes a synchronous pulse is determined by detecting whether there is a positive pulse higher than a positive threshold followed by a negative pulse lower than a negative threshold. The pulse signal detection method includes: comparing the synchronous signal with the positive threshold; comparing the synchronous signal with the negative threshold; and determining that the synchronous pulse exists when the positive pulse of the synchronous signal is higher than the positive threshold and the negative pulse of the synchronous signal is lower than the negative threshold in a post detection period after the positive pulse of the synchronous signal is determined higher than the positive threshold.

Abstract: Isolated DC-DC converters are described. A DC-DC converter is a device which converts a direct current (DC) signal from one voltage to another. An isolated DC-DC converter performs the conversion across an electrical isolation barrier separating two voltage domains. The signal converted from one voltage to another, and transferred from one voltage domain to another, may be a power signal. Described are isolated DC-DC converters which transfer a power signal from one voltage domain to another via an isolator, and a power feedback signal back across the isolator. The isolator is a transformer in some situations.

Abstract: A controller for a DCX power converter includes an SR controller that controls conduction times of first and second SR transistors in response to respective conduction conditions thereof, and a primary side controller that provides first and second primary phase signals controlling first and second transistors, measures a first sense signal as a time between a gate voltage of the first SR transistor falling below a first threshold and an activation of the second primary phase signal, an adaptive dead time proportional to an average of current conducted in the SR transistors during their respective active times, a first reference signal as a predetermined delay time plus the adaptive dead time, and a first error signal as an average difference between the first sense signal and the first reference signal, and controls a switching speed of the first and second primary phase signals to reduce the first error signal.

Abstract: System controller and method for regulating a power converter. For example, the system controller includes a first controller terminal and a second controller terminal. The system controller is configured to: receive, at the first controller terminal, an input signal; generate a drive signal based at least in part on the input signal, the drive signal being associated with an on-time period and an off-time period, the on-time period including a first beginning and a first end; and output, at the second controller terminal, the drive signal to a switch to close the switch during the on-time period and open the switch during the off-time period to affect a current associated with a secondary winding of the power converter. The system controller is further configured to detect a demagnetization period associated with the secondary winding based at least in part on the input signal.

Abstract: A power converter including a rectifier circuit and a method for rectifying an incoming alternating current. The rectifier circuit may alter its output voltage according to varying conditions of the power converter. The variations may include voltage changes at the input or output.

Abstract: A method and system for self-powering a clock input buffer is disclosed. The system includes an input node adapted to receive an alternating current (AC) signal having an instantaneous voltage oscillating between a minimum voltage and a maximum voltage. The system includes a pass transistor having a voltage controlled terminal, a first transfer terminal, and a second transfer terminal. The first transfer terminal connects to the input node and the second transfer terminal connects to a power node. The circuit also includes a plurality of transistors adapted to form a logic gate connected to the power node, and having a sensing terminal connected to the input node and an output terminal connected to the voltage controlled terminal. The logic gate produces a control voltage on the output terminal in response to an input voltage on the sensing terminal. The circuit also includes an energy-storage element having a first terminal connected to the power node.

Abstract: An apparatus comprises an isolated power converter coupled to an input dc power source, wherein the isolated power converter comprises a first switch network coupled to a first transformer winding and a second switch network coupled to a second transformer winding and a non-isolated power converter coupled to the second switch network of the isolated power converter, wherein a current flowing through the non-isolated power converter is a fraction of a current flowing through the isolated power converter.

Abstract: A controller for use in a power converter with multiple outputs includes a discharge detect circuit coupled to receive a voltage signal from a transformer winding of the power converter to output a discharge signal in response to the voltage signal. A multi-output signal process and interface block is coupled to output request signals to the output selection drive and idle ring visibility logic circuit. An output selection drive and idle ring visibility logic circuit is coupled to receive the discharge signal from the discharge detect circuit and the output request signals from the multi-output signal process and interface block. An idle ring detection circuit is coupled to one of the plurality of output switches and coupled to output an idle ring output signal to generate a next request pulse.

Abstract: An AC-DC converter with secondary side control and synchronous rectifier (SR) architecture and method for operating the same are provided for reducing the cost, complexity and size of the converter while improving efficiency. Generally, the secondary side controller includes a zero-crossing detector block, a negative-sensing block, a peak-detector block and a line-feed-forward block integrated in an integrated circuit (IC), and coupled to a secondary side of the converter through a single SR-sense (SR_SNS) pin through which the IC is coupled to a drain of the SR. The single SR_SNS pin has a maximum input voltage less than a rectified AC input voltage input to a secondary side of the converter, and, in one embodiment, is coupled to the drain of the SR through a voltage divider circuit including circuit elements both internal and external to the IC along with a rectifier element in series with the internal resistor.

Abstract: The power supply control unit includes an on trigger signal generating unit arranged to generate an on trigger signal for turning on the switching element on the basis of a feedback signal of flyback voltage, a first timer arranged to measure a predetermined minimum OFF time, a second timer arranged to measure time based on an ON time, a minimum OFF time setting unit arranged to compare the predetermined minimum OFF time measured by the first timer with the time measured by the second timer so as to set a longer time as a minimum OFF time, and an on timing determining unit arranged to determine timing for turning on the switching element on the basis of the set minimum OFF time and the on trigger signal.