Abstract: A voltage converter provides a desired voltage droop with load while avoiding output current sensing and active control/feedback circuits and avoiding excessive power dissipation from passive components by placing a sensing resistor in the low current, switched input circuit of the voltage converter. Therefore, the resistor conducts only when a switch controlling voltage conversion is conductive, generally at very low duty cycle and low current.

Abstract: A discharge lamp lighting control device (100) having a DC power converter, a power factor improving power converter (1), a polarity reversing circuit (2), a starter circuit (3), and a controller (4). The power factor improving power converter 1 includes a switching device S, a power factor improver, and a power converter. The power factor improver operates to smooth a rectified voltage by storing energy in a first inductive device L1 and by discharging energy from a second inductive device L2, in which the first and second inductive devices are magnetically coupled together. The storing and discharging is performed by turning ON and OFF the switching device S. A predetermined DC voltage is converted by energy stored and discharged by a third inductive device L3 in response to the turning ON and OFF of the switching device S.

Abstract: A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.

Abstract: A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. A magnetic core with a unique woven topology provides inverse coupling between the inductors. The inductors can comprise straight conductors since the magnetic core has the woven topology wrapped around each inductor. The inductors have a reduced electrical resistance since they are straight and do not loop around the magnetic core. The reduced electrical resistance increases energy efficiency and improves transient response of the circuit. The magnetic core can comprise top and bottom portions that are magnetically connected. The inductors can comprise straight circuit board traces and the circuit board can have holes to accommodate the magnetic core.

Abstract: A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. A magnetic core with a unique woven topology provides inverse coupling between the inductors. The inductors can comprise straight conductors since the magnetic core has the woven topology wrapped around each inductor. The inductors have a reduced electrical resistance since they are straight and do not loop around the magnetic core. The reduced electrical resistance increases energy efficiency and improves transient response of the circuit. The magnetic core can comprise top and bottom portions that are magnetically connected. The inductors can comprise straight circuit board traces and the circuit board can have holes to accommodate the magnetic core.

Abstract: A discharge lamp lighting control device (100) having a DC power converter, a power factor improving power converter (1), a polarity reversing circuit (2), a starter circuit (3), and a controller (4). The power factor improving power converter 1 includes a switching device S, a power factor improver, and a power converter. The power factor improver operates to smooth a rectified voltage by storing energy in a first inductive device L1 and by discharging energy from a second inductive device L2, in which the first and second inductive devices are magnetically coupled together. The storing and discharging is performed by turning ON and OFF the switching device S. A predetermined DC voltage is converted by energy stored and discharged by a third inductive device L3 in response to the turning ON and OFF of the switching device S.

Abstract: A voltage converter uses a component such as a JFET or four-terminal power MOSFET having no body diode and exhibiting no body diode conduction characteristic as a synchronous rectifier to reduce switching losses and body diode conduction losses and to support high frequency switching so that use of smaller components and higher current densities can be achieved. These effects are enhanced by a self-driven circuit utilizing positive feedback to enhance switching speed and reduce switching losses which increase with switching frequency.

Abstract: A voltage converter provides a desired voltage droop with load while avoiding output current sensing and active control/feedback circuits and avoiding excessive power dissipation from passive components by placing a sensing resistor in the low current, switched input circuit of the voltage converter. Therefore, the resistor conducts only when a switch controlling voltage conversion is conductive, generally at very low duty cycle and low current.

Abstract: A two-stage power converter that dynamically adjusts to output current requirements includes a first stage regulator that provides power to a second stage regulator. The first stage can be a buck converter, and the second stage can be a multiple-phase buck converter. The output voltage of the first stage (intermediate bus voltage Vbus) is varied according to the load current to optimize conversion efficiency. To provide maximum efficiency, the Vbus voltage is increased as load current increases. The Vbus voltage provided by the first stage can be varied by duty cycle or operating frequency control. In another embodiment, the switching frequency of the second stage is varied as output current changes so that output current ripple is held constant. In an embodiment employing a multiple-phase buck converter in the second stage, the number of operating phases are varied as output current changes.

Abstract: A converter has a transformer with primary and secondary windings each having n coils in a series-series arrangement connected to primary and secondary sides. The primary side has n primary legs each having a top switch and a bottom switch and connected to the primary winding therebetween. The secondary side has n secondary legs, each secondary leg has a synchronous rectifier switch and an output filter inductor connected to the secondary winding therebetween. A complimentary control for the primary side comprising a gate driver transformer with primary winding in series with a DC blocking capacitor connected to a drain and a source of the top switch of each primary leg, and a gate drive transformer, for each primary leg, with secondary winding containing a leakage inductor and in series with a DC blocking capacitor and a damping resistor connected to gate and source of the secondary side synchronous rectifier.

Abstract: A two-stage power converter that dynamically adjusts to output current requirements includes a first stage regulator that provides power to a second stage regulator. The first stage can be a buck converter, and the second stage can be a multiple-phase buck converter. The output voltage of the first stage (intermediate bus voltage Vbus) is varied according to the load current to optimize conversion efficiency. To provide maximum efficiency, the Vbus voltage is increased as load current increases. The Vbus voltage provided by the first stage can be varied by duty cycle or operating frequency control. In another embodiment, the switching frequency of the second stage is varied as output current changes so that output current ripple is held constant. In an embodiment employing a multiple-phase buck converter in the second stage, the number of operating phases are varied as output current changes.

Abstract: A non-isolated bridge-buck DC—DC converter has self-driven synchronous rectifiers Q5 Q6 in the buck circuits 28 30. Gate electrodes of the synchronous rectifiers Q5 Q6 are connected to midpoints 24A 24B of the bridge circuit. The voltage at the midpoints provides the necessary voltage waveform for switching the synchronous rectifiers Q5 Q6. In another aspect of the invention, voltage shift circuits 34 are provided between the midpoints and the gates of the synchronous rectifiers. The voltage shift circuits are necessary in some embodiments to make sure that the synchronous rectifiers are turned completely OFF when necessary. The present invention provides a more power efficient and less expensive technique for controlling the synchronous rectifiers compared to conventional external driver circuitry.

Abstract: A non-isolated bridge-buck DC-DC converter has self-driven synchronous rectifiers Q5 Q6 in the buck circuits 28 30. Gate electrodes of the synchronous rectifiers Q5 Q6 are connected to midpoints 24A 24B of the bridge circuit. The voltage at the midpoints provides the necessary voltage waveform for switching the synchronous rectifiers Q5 Q6. In another aspect of the invention, voltage shift circuits 34 are provided between the midpoints and the gates of the synchronous rectifiers. The voltage shift circuits are necessary in some embodiments to make sure that the synchronous rectifiers are turned completely OFF when necessary. The present invention provides a more power efficient and less expensive technique for controlling the synchronous rectifiers compared to conventional external driver circuitry.