Abstract: A device and method that includes a shunt regulator of a universal serial bus (USB) compatible power supply device is disclosed. The shunt regulator includes an amplifier with an output, a first input, and a second input. The shunt regulator also includes a current digital-to-analog converter (DAC) that is coupled to the first input of the amplifier and a voltage bus node. The current DAC adjusts a sink or a source current delivered at the first input of the amplifier to regulate a programmable output voltage (Vbus) in the USB-compatible power supply device. The current delivered by the DAC is responsive to receipt of a digital code indicative of a programmable power supply command specifying the Vbus to be delivered by the USB-compatible power supply device on the voltage bus node.

Abstract: An object of the present invention is to synchronize PWM between individual phases of an IPM, so that the IPM has a simplified-scale circuit. An IPM according to the present invention includes a DC-DC converter including a multi-phase arm having a plurality of phase arms connected in parallel on a secondary side, a secondary-wire-voltage detection circuit configured to detect a secondary wire voltage in each phase arm of the DC-DC converter, and a synchronization-signal generation circuit configured to generate a synchronization signal in each phase arm on the basis of the behavior of the secondary wire voltage.

Abstract: The present invention provides a power control circuit and a power device using the power control circuit, wherein quasi resonance is performed by the power control circuit using a coil, current flowing in the coil is monitored by a simple configuration, and a zero cross point or a bottom in resonance is detected. The present invention provides a power control circuit and a power device using the power control circuit. The power control circuit includes a detection circuit connected to a drain of MOSFET, the MOSFET serially connected between an inductor connected to an alternating-current wire and a current sensing resistor connected to ground potential; and a quasi resonance control circuit connected to the detection circuit and the MOSFET for performing quasi resonance control to inductor-current at a zero cross point or a bottom point in a time sequence of discharging while conducting the inductor-current of the inductor.

Abstract: Methods and apparatus to provide a high-efficiency drive for a floating gate are disclosed. An example apparatus includes a driver including a supply terminal, the driver configured to output a third voltage corresponding to the supply terminal, the driver to drive a gate of a transistor in a power converter; and a second capacitor to be charged using a first discharging current of a first capacitor and discharged at the supply terminal of the driver, the driver to drive the gate of the transistor based on a second discharging current from the second capacitor.

Abstract: A switching converter having a high-side switching transistor and a low-side switching transistor and an inductor, having a circuit for generating a simulated waveform representing a sawtooth inductor current waveform. A circuit for monitoring and voltage at a switch node between the high-side and low-side transistors to determine a time during which the inductor current is increasing and a time during which the inductor current is decreasing wherein voltage across the low-side transistor when it is conducting represents a first portion of the simulated sawtooth inductor current waveform. A circuit for utilizing the time when the inductor current is increasing, the time when the inductor current is decreasing and the voltage across the low-side transistor when it is conducting to generate a portion of the simulated inductor current waveform when the high-side transistor is conducting. A method and a power supply utilizing this circuit are also disclosed.

Abstract: A lighting device includes a switch coupled to receive DC input, and driven on/off by received gate drive signals to provide current through a primary transformer winding. A large output capacitor is coupled across output terminals for receiving a load. An output circuit is coupled between a secondary transformer winding and the output capacitor, and includes a small buffer capacitor and a buffer diode. A feedback circuit compares a voltage across the buffer capacitor with a reference signal and provides a feedback control signal for regulating the switch and accordingly the device output to the load. An auxiliary power supply includes a tertiary transformer winding and powers the feedback circuit. By implementing the voltage across the buffer capacitor, the discharge time during a non-standard operating condition (e.g., no load) is small enough to enable continuous operation of the auxiliary power supply, the feedback circuit and the switch.

Abstract: System and method for protecting a power converter. An example system controller for protecting a power converter includes a signal generator, a comparator, and a modulation and drive component. The signal generator is configured to generate a threshold signal. The comparator is configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter. The modulation and drive component is coupled to the signal generator.

Abstract: In accordance with an example embodiment of the invention, a three-phase power control device is configured to synchronize firing thyristor or SCR sets in consecutive combinations of two of the three phases, to supply current to consecutive combinations of two of the three loads in a three-phase load configuration, to determine real branch impedance of each load from three combinations of two supplied loads, without need of any electrical neutral reference.

Abstract: A DC/DC converter, including a piezoelectric element; a first switch, coupling a first electrode of the piezoelectric element to a first terminal of application of a first voltage; a second switch, coupling the first electrode of the piezoelectric element to a first terminal of supply of a second voltage; and at least one third switch connecting the first electrode to a second electrode of the piezoelectric element, said switches being cyclically controlled, at an approximately constant frequency with, between each turning-on of one of the switches, a phase where all switches are off.

Abstract: A power conversion apparatus including a circuit board, a transformer, a first circuit, a second circuit, a first main coil, and a second main coil is provided. The transformer, the first circuit, and the second circuit are disposed on the circuit board. The transformer has a first winding and a second winding. The first circuit is coupled to and provides an input voltage to the first winding. The first end of the second winding is configured to provide an output voltage. The second circuit is coupled to the second winding. The first main coil is coupled to the first circuit. The second main coil is printed on the circuit board and coupled between the second circuit and a first reference potential terminal. The first main coil and the second main coil are electrically insulated from each other and magnetically coupled to each other.

Abstract: The present application discloses a DC-to-DC converter circuit and a circuit board layout structure for the same. The DC-to-DC converter circuit is electrically connected between a first power supply side and a second power supply side, and comprises a first branch with a primary side coupled to the first power supply side and a secondary side coupled to the second power supply side; a second branch with a primary side coupled to the first power supply side and a secondary side coupled to the second power supply side; and a first inductor. The secondary sides of the first branch and the second branch are connected in series via the first inductor.

Abstract: System and method for protecting a power converter. An example system controller for protecting a power converter includes a signal generator, a comparator, and a modulation and drive component. The signal generator is configured to generate a threshold signal. The comparator is configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter. The modulation and drive component is coupled to the signal generator.

Abstract: A DC-DC buck converter includes a buck conversion circuit, a PWM control circuit and a light-load control circuit. A switching circuit in the buck conversion circuit includes multiple upper switching elements and lower switching elements. The PWM control circuit is coupled to the buck conversion circuit and output a control signal to control the upper and lower switching elements. The light-load control circuit, coupled to the PWM control circuit and the buck conversion circuit for receiving an output voltage, the control signal and a light-load threshold value. The light-load control circuit is provided to determine whether the DC-DC buck converter is in a light load state and turn off at least one of the upper switching elements and at least one of the lower switching elements in the light load state.

Abstract: In a described example, a method includes using a power supply, supplying an output voltage that varies in response to a reference voltage; detecting a voltage ramp in an input reference voltage; generating an offset voltage waveform; adding the offset voltage waveform to the input reference voltage to generate a second reference voltage; and using the second reference voltage, operating the power supply to supply the output voltage.

Abstract: A synchronous rectifier applied to a secondary side of a power converter includes a forbidden turning-on time generation circuit, a green mode signal generation circuit, and a controller. The forbidden turning-on time generation circuit generates a forbidden turning-on time corresponding to the secondary side according to a synchronous signal of the secondary side. The green mode signal generation circuit enables a green mode signal when the forbidden turning-on time is greater than a reference value by at least one time, and disables the green mode signal when the forbidden turning-on time is continuously less than a reference value by a predetermined number of times. The reference value is changed with an output voltage of the secondary side. The controller enters a green mode when the green mode signal is enabled, and leaves the green mode when the green mode signal is disabled.

Abstract: A power supply device has a switch and a coil connected in series with alternating-current input power. A first rectifier connected across the coil performs boost rectification, and a voltage across an output smoothing capacitor is charged to obtain output power.

Abstract: An auto-calibrated current sensing comparator is provided. A secondary dynamic comparator shares the same inputs and acts to adjust a calibration control of the current sensing comparator. The calibration control may be in the form of adjusting the offset of the current sensing comparator or adjusting a propagation delay that is added to its output.

Abstract: A power conversion apparatus includes a primary-side circuit, a bulk capacitor, a conversion circuit, and a master control circuit. The primary-side circuit is adapted to rectify and boost an alternating-current power and output primary-side output. The bulk capacitor is connected in parallel to two output ends of the primary-side output. The conversion circuit is configured to receive the primary-side output passing through the bulk capacitor and convert the primary-side output into secondary-side output. The master control circuit detects an electric power state of the alternating-current power, obtains a time interval, a power of the secondary-side output corresponding to the time interval, and two of the capacitor voltages corresponding to the start and the end of the time interval when the electric power state is power-off, and selectively outputs an abnormal signal according to the time interval, the power, the capacitor voltages, and a threshold.

Abstract: Systems and methods for power conversion are described. Symmetric topologies and modulation schemes are described that may reduce common-mode noise. For example, a system may include a transformer including a first secondary winding and a second secondary winding; a rectifier, including a set of switches, that connects taps of the first secondary winding and the second secondary winding to a first terminal and a second terminal, wherein the rectifier is symmetric with respect to the first secondary winding and the second secondary winding; a battery connected between the first terminal and the second terminal; and a processing apparatus that is configured to control the set of switches to rectify a multilevel voltage signal on the transformer, including: selecting a modulation scheme from among two or more modulation schemes based on a measured voltage level of the battery.

Abstract: System and method for protecting a power converter. An example system controller for protecting a power converter includes a signal generator, a comparator, and a modulation and drive component. The signal generator is configured to generate a threshold signal. The comparator is configured to receive the threshold signal and a current sensing signal and generate a comparison signal based on at least information associated with the threshold signal and the current sensing signal, the current sensing signal indicating a magnitude of a primary current flowing through a primary winding of a power converter. The modulation and drive component is coupled to the signal generator.