Abstract: An inverter includes: a converter circuitry to convert an alternating-current voltage to a direct-current voltage; an inverter circuitry to convert a direct-current voltage obtained by conversion by the converter circuitry to an alternating-current voltage and to supply the alternating-current voltage obtained by conversion to a load; a current detector to detect an output current of the inverter circuitry; a calculator to calculate an output frequency based on the output current detected by the current detector, and a pulse-signal outputter to output a pulse signal based on the output frequency calculated by the calculator. The inverter circuitry converts the direct-current voltage obtained by conversion by the converter circuitry to the alternating-current voltage based on the pulse signal output from the pulse-signal outputter, so as to obtain a frequency corresponding to the magnitude of the load.

Abstract: A static synchronous compensator includes at least one converter pole for producing a first phase of an AC voltage waveform having a fundamental cycle. The first phase of the AC voltage waveform includes alternating converter pole charging and discharging regions in each fundamental cycle. The at least one converter pole includes a plurality of cascaded H-bridge cells, each having a DC voltage source and a plurality of switches. The switches are capable of being switched to produce a plurality of switching states. There is a controller configured to control the switching states of the plurality of switches of each of the cascaded H-bridge cells based on the voltages of DC voltage sources of the H-bridge cells and on whether the AC waveform is in the converter pole charging region or the converter pole discharging region.

Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may determine a period of a resonant oscillation of the voltage across the synchronous rectifier switch following at least one cycling off of the synchronous rectifier switch. The synchronous rectifier controller may adjust the minimum off-time period for the synchronous rectifier switch based on the period of the resonant oscillation. The synchronous rectifier controller may adaptively adjust a minimum off-time period for the synchronous rectifier switch.

Abstract: The present disclosure relates to power supplies and control methods for power supplies. Example power supplies include an output terminal, a transformer having a secondary winding including a first terminal and a second terminal, first and second diodes coupled between the output terminal and the first and second terminals, respectively, first and second switches coupled between the output terminal and the first and second terminals, respectively, and a controller coupled to the first switch and the second switch. The controller is configured to control the power supply in an asynchronous mode when output current is below a defined threshold so current flows to the output terminal through the first diode and the second diode, and to control the power supply in a synchronous mode when output current is above the defined threshold so current flows to the output terminal through the first switch and the second switch.

Abstract: A sense resistor is placed in series with an output capacitor of a buck converter. The buck converter operates in a discontinuous mode such that there is a dead time in each switching cycle. A control circuit senses a voltage across the sense resistor and thereby generates a first signal ICS. The control circuit detects an offset voltage in ICS, where the offset voltage is the voltage of ICS during the dead time in a first switching cycle. The control circuit level shifts the entire ICS by the offset voltage, thereby generating a second signal ICLS. ICLS has the same waveform as the waveform of the inductor current. In a second cycle, ICLS is used to determine when to turn off the main switch and when the start of the dead time occurs. ICLS and the offset voltage are used together to determine when to turn the main switch on.

Abstract: A rectifier circuit is described, which includes a cathode terminal, an anode terminal and, between the cathode terminal and the anode terminal, an electronic circuit which includes at least one MOSFET transistor including an integrated inverse diode, the drain-source breakdown voltage of the MOSFET transistor operated in the avalanche mode corresponding to the clamping voltage between the cathode terminal and the anode terminal of the rectifier circuit. In addition, a method is provided for operating a rectifier circuit which contains a cathode terminal, an anode terminal and, between the cathode terminal and the anode terminal, at least one MOSFET transistor including an integrated inverse diode, the drain-source breakdown voltage of the MOSFET transistor being selected in accordance with the clamping voltage between the cathode terminal and the anode terminal, and the MOSFET transistor being operated in the avalanche mode.

Abstract: A quiescent power supply including an AC/DC converter, a switch, an energy storage device, and a controller is disclosed. The switch is electrically coupled to the AC/DC converter to electrically disconnect the AC/DC converter from an AC supply line. The controller is operably coupled to the switch to actuate the switch. In particular, the controller can actuate the switch to disconnect the switch during when the AC/DC converter is idle.

Abstract: A voltage regulation device includes a first transistor, a first bias current source, a bias resistor, a second transistor, a second bias current source, and a detection adjustment circuit. The first transistor is coupled to the first bias current source for outputting a reference voltage. The bias resistor is coupled to the first transistor for receiving a regulation current. The second transistor has a first terminal for receiving a system voltage, a second terminal for outputting an output voltage, and a control terminal for receiving the reference voltage. The second bias current source is coupled to the second terminal of the second transistor. The detection adjustment circuit is coupled to the first transistor and the second transistor. When the output voltage is too low, the detection adjustment circuit activates the compensation current source to increase the voltage at the control terminal of the second transistor.

Abstract: An inverter includes transformers having identical characteristics. Exciting windings of the transformers are connected in parallel so that the transformers are excited simultaneously. Output windings of the transformers are connected in series so that waveforms of output voltages of the output windings are time-synchronized. Each transformer includes a core having an identical shape and including an inner leg having an independent closed magnetic circuit. The excitation winding and the output winding are wrapped around the inner leg of the core in layers. The inner leg of the core has a gap whose size is steplessly adjustable in a state where the excitation current is applied to the excitation winding. The size of the gap is adjusted to regulate exciting inductances of the transformers to a same predetermined value.

Abstract: Methods and apparatus are presented for sensing current flowing in a power transistor of a switch mode converter, in which a voltage is sensed across a first field effect transistor connected in a series circuit branch in parallel with the power transistor, and the sensed voltage is used to generate output signal to indicate the current flowing in the power transistor.

Abstract: A control circuit for a step-up converter includes a soft start module configured to control states of N transistor pairs of the step-up converter, where N is an integer greater than two. A driver module is in communication with the soft start module and configured to generate a first signal when N transistor pairs of the step-up converter are ready to switch. A first charging circuit is configured to charge (N-1) capacitors of the step-up converter to an input voltage of the step-up converter in response to the first signal and to generate a second signal when charging is complete. A second charging circuit is configured to sequentially charge the (N-1) capacitors of the step-up converter to (N-1) predetermined voltage values in response to the first signal and the second signal and before operation of the step-up converter begins.

Abstract: A power conversion device includes: a bridge circuit; a filter provided on an alternating current side of the bridge circuit, and connected to a neutral point; a reactor between the bridge circuit and the filter; a smoothing circuit provided on a direct current side of the bridge circuit; a snubber circuit between the bridge circuit and the smoothing circuit; and a switch circuit provided between the smoothing circuit and the snubber circuit. The smoothing circuit includes two smoothing capacitors connected in series between a positive line and a negative line. The neutral point is connected between the two smoothing capacitors. The snubber circuit includes two snubber capacitors connected in series between the positive line and the negative line. The neutral point is connected between the two snubber capacitors. The switch circuit includes a first switch provided on the positive line and a second switch provided on the negative line.

Abstract: A DC-DC converter includes a transformer, a switching circuit provided on the primary side of the transformer, and a rectifier circuit provided on the secondary side of the transformer. The rectifier circuit includes a first rectifier part that is serially connected body of a first transistor and a second transistor having a first electrode connected to a second electrode of the first transistor. The first and second transistors each include a parasitic diode connected forward between the second and first electrode, and the withstanding voltage between the first and second electrodes of the first transistor is higher than the withstanding voltage between the first and second electrodes of the second transistor.

Abstract: Some embodiments are directed to an AC/DC converter comprising a first AC terminal for connection to a first AC circuit terminal, a neutral line terminal for connection to a neutral AC circuit terminal, a common node, a first AC side active bridge coupled between the first AC terminal and the common node, and a neutral voltage lift capacitor coupled between the neutral line terminal and the common node. The converter comprises first and second DC terminals, and a capacitor between the first and second terminals. A DC-side active bridge is coupled between the first and second terminals. An inductor is coupled between switchable nodes of the first AC side active bridge and the DC side active bridge. A controller is arranged to control the first AC side active bridge and the DC-side active bridge so to alternate voltage across the first AC terminal and the neutral line terminal.

Abstract: A switch mode power supply includes an input, an output, and a power converter coupled between the input and the output. The power converter includes a transformer having a primary side and a secondary side, and a clamping circuit. The clamping circuit has a switching device coupled to the primary side of the transformer. The power supply further includes a control circuit coupled to the switching device. The control circuit includes at least one isolation component. The control circuit is configured to receive a signal from the secondary side of the transformer via the at least one isolation component, and control the switching device coupled to the primary side of the transformer in response to the signal received from the secondary side of the transformer via the at least one isolation component. Other example power supplies, power converters, control circuits, etc. are also disclosed.

Abstract: A DC-DC converter includes first and second converters. The first converter generates a first power voltage based on a power voltage from an input terminal, and outputs the first power voltage to a first output terminal. The second converter generates a second power voltage based on the input power voltage, and outputs the second power voltage to a second output terminal. The second converter includes a plurality of inverting converters and a controller. The inverting converters generate a check current to check a connection state of an inductor when the inductor is connected. The second power voltage is generated by converting the input power voltage in response to a PWM signal. The controller generates a driving control signal based on the check current to operate a predetermined number of the inverting converters connected to the inductor, and to control the inverting converters based on the driving control signal.

Abstract: In one embodiment, an undervoltage protection circuit for a switching power supply can include: (i) an undervoltage detection circuit that determines whether an input voltage of the switching power supply is in an undervoltage state; (ii) a selection circuit configured to select a first or a second control signal to be provided as a main control signal to a control circuit; (iii) the control circuit being configured, in response to the main control signal being the first control signal, to control a switching operation of a power transistor in the switching power supply such that an output voltage of the switching power supply is maintained as substantially stable; and (iv) the control circuit being configured, in response to the main control signal being the second control signal, to control the switching operation of the power transistor to reduce an input power of the switching power supply.

Abstract: A circuit includes a current sensor to sense a switching current flowing at input side of a switching DC-DC converter. An output capacitor filters an output voltage at an output side of the switching DC-DC converter. A feed-forward circuit passes a portion of the sensed switching current to a feedback path on the output side of the switching DC-DC converter simulating a changing effective series resistance (ESR) of the output capacitor to facilitate operating stability in the switching DC-DC converter.

Abstract: A rectifying circuit for high-frequency power supply that rectifies an alternating voltage at a high frequency exceeding 2 MHz, the rectifying circuit for high-frequency power supply including a bridge rectifier circuit that rectifies the alternating voltage inputted from a reception antenna for power transmission, a matching functional circuit that matches a resonance condition to that of the reception antenna for power transmission, and a smoothing functional circuit that smooths the voltage rectified by the bridge rectifier circuit into a direct voltage, in which the rectifying circuit for high-frequency power supply causes the bridge rectifier circuit to perform partial resonant switching in a switching operation at the time of rectification by using the matching functional circuit and the smoothing functional circuit.

Abstract: Disclosed are apparatuses and methods for implementing CMOS-based, process insensitive current reference circuit(s). An apparatus includes a constant transconductance circuitry including a first and second current mirrors and respectively generating constant currents across one or more process corners, a resistive transistor in the constant transconductance circuitry having a resistance, and a feedback circuitry coupled with the resistive transistor and the constant transconductance circuitry to form a constant current source. The apparatus may optionally include a data processing module as well as another constant transconductance circuitry, another resistive transistor, and another feedback circuitry that form another constant current source.