Abstract: There is disclosed a controller for a DC-DC converter comprising a series arrangement of a high-side switch and low-side switch with a half-bridge node therebetween, the controller comprising a high-side part for driving the high-side switch and configured to be powered, when the low-side switch is open, by a rechargeable power supply connected between the half-bridge node and a power supply node, the high-side part comprising a level shifter, driver, latch part comprising a latch having set and reset inputs and configured to latch the driver to either an on-state or an off-state, and a further circuit, wherein the latch part is configured and adapted to prevent the further circuit from drawing current from the power supply unless at least one of the set input is high and the driver is in the on-state. A DC-DC converter having such a controller is also disclosed, as are methods of operating a converter.

Abstract: There is disclosed a controller for a DC-DC converter comprising a series arrangement of a high-side switch and low-side switch with a half-bridge node therebetween, the controller comprising a high-side part for driving the high-side switch and configured to be powered, when the low-side switch is open, by a rechargeable power supply connected between the half-bridge node and a power supply node, the high-side part comprising a level shifter, driver, latch part comprising a latch having set and reset inputs and configured to latch the driver to either an on-state or an off-state, and a further circuit, wherein the latch part is configured and adapted to prevent the further circuit from drawing current from the power supply unless at least one of the set input is high and the driver is in the on-state. A DC-DC converter having such a controller is also disclosed, as are methods of operating a converter.

Abstract: A method of igniting a lamp is disclosed. The lamp may be a compact fluorescent lamp. The method is directed in particular to reducing or eliminating hard-switching of half-bridge switches driving a lamp. The method operates by reducing the on-time of at least one of the switches, in response to saturation of the ballast inductor. The method can operate immediately upon saturation of the ballast inductor, or allow a predetermined level of saturation. The method operates by increasing the slope of the sawtooth timing circuit.