Abstract: A switching DC-DC converter includes: an output voltage detecting unit configured to detect a DC output voltage; an error amplifying unit configured to compare the detected output voltage and a reference voltage and configured to supply an amplified error signal between the detected output voltage and the reference voltage to the pulse width modulating unit; and a single oscillating unit connected to an output of the output voltage detecting unit and an output of the error amplifying unit and operable on a first oscillating mode and a second oscillation mode. The oscillating unit on the first oscillating mode controls a switching frequency of the power switch based on the detected output voltage. The oscillating unit on the second oscillating mode controls the switching frequency of the power switch based on the amplified error signal.

Abstract: A freewheeling DC/DC step-down converter includes a high-side MOSFET, an inductor and an output capacitor connected between the input voltage and ground. A freewheeling clamp, which includes a freewheeling MOSFET and diode, is connected across the inductor. When the high-side MOSFET is turned off, a current circulates through the inductor and freewheeling clamp rather than to ground, improving the efficiency of the converter. The converter has softer diode recovery and less voltage overshoot and noise than conventional Buck converters and features unique benefits during light-load conditions.

Abstract: The invention relates to a switch-mode power converter including a bias circuit. A power converter power transformer includes a magnetic core. The switch-mode power converter power transformer also includes an initial bias primary winding and an initial bias secondary winding, both wound on the magnetic core, wherein the initial bias secondary winding shares at least one magnetic path in common with the initial bias primary winding. A driver is configured to drive the initial bias primary winding with high frequency pulses when enabled by an enable signal. A rectifier and capacitor are configured to provide a voltage to power a control circuit during a power converter start-up. A method provides an initial bias power for a power converter output side referenced controller, powering the output side referenced controller from the initial bias windings.

Abstract: A voltage regulator and method of using the same are provided that improve wakeup-time and reduce power wastage in switching a device from standby or sleep-mode to active mode. Generally, the voltage regulator includes: (i) a standby regulator having a high-impedance node (NGATE); (ii) an active regulator having a high-impedance node (dominant pole node); (iii) a compensation capacitor; and (iv) a switching circuit to couple the compensation capacitor to the high-impedance node (NGATE) of the standby regulator while the device is in sleep-mode to pre-charge the compensation capacitor, and to couple the compensation capacitor to the high-impedance node (dominant pole node) of the active regulator while the device is in active or non-sleep-mode. Other embodiments are also disclosed.

Abstract: A circuit for minimizing voltage inrush upon startup in a switching power converter having a switching stage including high and low switches connected at a common node, a feedback loop for maintaining a target output voltage, an output capacitor connected between an output node and the ground, an inductor connected between the common node and the output node, and a control circuit having a first error amplifier for providing a first signal based on a comparison of a reference voltage and voltage provided by the feedback loop, the control circuit including a level switch connected between the ground and the common node, the level switch being controlled in accordance with the first signal, wherein a large inrush current flowing into the output capacitor when the circuit is starting up is minimized.

Abstract: The disclosed embodiments relate to apparatus and method for reducing power losses in a power supply. There is provided an apparatus comprising means for coupling a first signal (S2) to a reference level (ground) when the coupling means is conductive, means for placing the coupling means in a conductive state during a duration of a portion of a period of a second signal (S3), and means for altering the duration of conduction of the coupling means in response to an amplitude of the second signal.

Abstract: System and method for protecting a power converter. A system includes a threshold generator configured to generate a threshold signal, and a first comparator configured to receive the threshold signal and a first signal and to generate a comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and adjust the input current for the power converter. The threshold signal is associated with a threshold magnitude as a function of time. The threshold magnitude increases with time at a first slope during a first period, and the threshold magnitude increases with time at a second slope during a second period. The first slope and the second slope are different.

Abstract: A synchronous rectifier, including an energy storage element having a terminal; a power supply input, connected to the terminal of the storage element in a first time interval; a reference line connected to the terminal of the storage element in a second time interval; and a zero comparator, coupled to the terminal of the storage element to detect a current flowing in the energy storage element and disconnect the terminal of the storage element from the reference line upon detecting a zero current, the zero comparator having an offset and a propagation time; the zero comparator further having an offset control input and an output. An offset regulating loop is coupled between the output of the zero comparator and the offset control input and regulates the offset of the zero comparator to compensate the propagation time.

Abstract: A power supply includes a power source having at least one power source output, and a plurality of drivers connected to the at least one power source output. At least one of the plurality of drivers includes a bridge network having a first switch, a second switch and a bridge network output. The first switch is connected between the at least one power source output and the bridge network output. The second switch is connected between the bridge network output and a ground. The bridge network further includes at least one control input connected to the second switch. The bridge network is adapted to change a state of the first switch based on a state of the second switch.

Abstract: Charge pumps and methods for regulating charge pumps. The charge pump includes a voltage booster circuit and a voltage regulator circuit. The voltage booster circuit includes first and second input terminals that respectively receive a regulation voltage and an input voltage. The voltage booster circuit generates an output voltage having a polarity that is different from the input voltage. The output voltage is adjusted by the regulation voltage and provided to an output terminal. The voltage regulator circuit is coupled between the first input terminal and the output terminal of the voltage booster circuit. The voltage regulator circuit shifts the output voltage to a level shifted voltage and generates the regulation voltage responsive to the level shifted voltage.

Abstract: A synchronous-rectification-type switching regulator is disclosed that includes a first switching element; an inductor charged with a voltage input to an input terminal of the switching regulator by the switching of the first switching element; a second switching element for synchronous rectification performing switching so as to discharge the inductor; a control circuit part controlling the switching of the first switching element so that an output voltage from an output terminal of the switching regulator is a predetermined constant voltage, and to cause the second switching element to perform the switching inversely to the first switching element; and a reverse current prevention circuit part interrupting a current that flows into the second switching element by cutting off the connection of the second switching element so as to prevent generation of a reverse current that flows in the direction of the second switching element from the output terminal.

Abstract: A one-phase static var compensator apparatus includes a compensator string consisting of a first static var compensator connected serially to a thyristor valve. The compensator string is arranged to be connected on its first end to one phase of a transmission grid of a rated voltage exceeding 69 kV. Moreover, the thyristor valve includes a plurality of thyristors connected serially and the compensator string is arranged to be directly connected to the transmission grid. A corresponding three phase apparatus is also presented.

Abstract: A freewheeling MOSFET is connected in parallel with the inductor in a switched DC/DC converter. When the freewheeling MOSFET is turned on during the switching operation of the converter, while the low-side and energy transfer MOSFETs are turned off, the inductor current circulates or “freewheels” through the freewheeling MOSFET. The frequency of the converter is thereby made independent of the lengths of the magnetizing and energy transfer stages, allowing far greater flexibility in operating and converter and overcoming numerous problems associated with conventional DC/DC converters. For example, the converter may operate in either step-up or step-down mode and may even transition for one mode to the other as the values of the input voltage and desired output voltage vary.

Abstract: A switching power supply unit is provided which provides improved response for frequency switching with a smooth rise in voltage. The switching power supply unit includes: a rectifier circuit for rectifying an alternating current from an AC power source into a direct current; a switching circuit for switching the current rectified by this rectifier circuit using a switching device; a pulse oscillator circuit for outputting a switching signal to the switching device; and a transformer circuit for stepping a voltage up or down depending on the current switched by this switching circuit. A frequency switching unit is also used to detect a pulse output from the switching circuit. Based on the state of this pulse output, the frequency switching unit changes a resistance using resistors, thereby switching the frequency of the switching signal in the pulse oscillator circuit.

Abstract: A device for protecting an electronic converter, e.g. for halogen lamps, includes a comparator having an output as well as non-inverting and inverting inputs for receiving a first input signal indicative of the load applied to the converter and a second input signal indicative of the temperature of the converter. The comparator is in a non-inverting Schmitt-trigger configuration having an input-output characteristic with hysteresis. Consequently, the output is switched from a first value to a second value to switch off the electronic converter as the first input signal exceeds a first threshold value. The output is switched back from the second value to the first value to restart the electronic converter when the first input signal falls below a second threshold value. The second threshold value is lower than the first threshold value, and both threshold values are a function of the signal indicative of the temperature of the converter.

Abstract: A controller is provided for DC-DC converters of the type associated with a half-bridge driving stage of at least one inductive load, with a pair of power MOS transistors in Highside and Lowside configuration being driven by a corresponding converter. The controller includes an input for connection to a terminal of the inductive load. The controller also includes a read block for reading an inductive load phase current at the terminal, an over current comparator having a first input coupled to an output of the read block, and a bypass compensation network including an error amplifier block having a first input coupled to the terminal through a voltage divider, and a second input coupled to a reference potential. The compensation network has an output that is coupled to a second input of the over current comparator, and an output of the over current comparator is supplied to the DC-DC converter.

Abstract: A headroom compensation circuit for a voltage converter for ensuring that there is adequate headroom voltage to enable accurate operation of the current sense amplifier sensing the output current of the converter, the headroom compensation circuit comprising an error amplifier for comparing an output voltage of the converter to a reference voltage to set the converter output voltage; and a circuit for providing a bias current to an input of the error amplifier when a supply voltage to the current sense amplifier within a predefined threshold of the converter output voltage to cause the error amplifier to reduce the converter output voltage thereby to increase the headroom voltage for the current sense amplifier, said headroom voltage being defined as a voltage between the supply voltage to the current sense amplifier and said converter output voltage.

Abstract: A high-reliability IGBT drive device in which the high- and low-voltage side IGBTs are complementarily ON/OFF controlled before and after dead time. A reset pulse that turns OFF the high-voltage side IGBT is generated during the dead time as described in the following example. The reset pulse is generated immediately before an ON instruction for the low-voltage side IGBT, so that a period that begins immediately before the ON instruction for the low-voltage side IGBT and overlaps with the ON instruction, continuously during the dead time, continuously during dead time immediately before the low-voltage side IGBT turns ON, or in such a manner as to invalidate the ON instruction for the low-voltage side IGBT when an ON state of the high-voltage side IGBT is observed.

Abstract: A DC converter comprises a half bridge supply circuit and one or more flyback or forward converter output circuits, and optionally also an LLC converter whose control can determine a common variable switching frequency. The half bridge supply circuit produces a 50% duty output alternating between two input voltages, such as zero and a voltage Vin. In each flyback or forward converter output circuit, a switch connects a transformer primary to the half bridge supply circuit output in a PWM controlled manner to regulate a respective flyback or forward converter DC output which is produced by the converter output circuit, with a duty ratio less than 50% whereby switching losses are reduced. Soft switching is further facilitated by the half bridge supply circuit having two transistors controlled in a complementary manner.

Abstract: A resonant DC/DC converter for supplying an output power comprises a switching device (18) for supplying a switched voltage (UWR) to a resonant circuit (20) having a transformer (T). The switched voltage (UWR) is derived from an intermediate circuit voltage (Uz) having a fixed pulse width and frequency so that the zero crossings of the resonant current (Ires) generated in the resonant current are defined. The switching configuration of an inverter circuit (18) is selected by a control device (31) to either increase, decrease or maintain at a substantially constant level the resonant current according to the polarity of the switched voltage, so as to control the output power as required.