Patent application number | Description | Published |
20090108775 | LED DRIVER WITH ADAPTIVE ALGORITHM FOR STORAGE CAPACITOR PRE-CHARGE - A method is provided for driving a plurality of light emitters in a plurality of output paths with each output path including at least one light emitter. The method includes the steps of applying a supply voltage level to a plurality of output paths; generating a current for each path during a period of a predetermined length for the output path; sensing a current level for each output path during the period; comparing each sensed current level with a reference level; increasing the supply voltage level if the sensed current level is lower than the reference level; determining a lowest supply voltage level for the worst case output path; and using the lower supply voltage level as a common supply voltage level for all output paths. | 04-30-2009 |
20090121644 | ADAPTIVE ALGORITHM FOR CAMERA FLASH LED POWER CONTROL VS. BATTERY IMPEDANCE, STATE OF DISCHARGE (SOD), AGING, TEMPERATURE EFFECTS - A method for driving a light-emitting semiconductor is provided. A supply voltage is converted into a secondary output voltage for supplying the light-emitting semiconductor with an output voltage. A level for the supply voltage at the beginning of a high current phase of the light-emitting semiconductor is sensed. A threshold voltage level for the supply voltage level is determined based on the sensed level. The high current phase with the light-emitting semiconductor is stated. The sensed level is continuously compared with the threshold voltage level, and an output current through the light-emitting semiconductor is controlled such that the sensed level does not drop below the threshold voltage level. | 05-14-2009 |
20090206772 | DC-DC CONVERTER AND METHOD FOR MINIMIZING BATTERY PEAK PULSE LOADING - The invention relates to an electronic device, comprising a DC-DC converter for converting a primary supply voltage into an output voltage at an output node to be coupled to a super capacitor and a control stage for operating the regulated DC-DC converter in a forward direction in a boost mode providing a boost voltage level at the output node and for operating the regulated DC-DC converter in a reverse direction in a buck mode providing a buck voltage level at an auxiliary node arranged between a primary voltage supply providing the primary supply voltage and the output node, wherein the control stage is adapted to control the DC-DC converter when operating in reverse direction to provide a current to the auxiliary node using the super capacitor as a power source. | 08-20-2009 |