Patent attributes
An apparatus method and system are provided for power conversion, to supply power to a nonlinear load such as a plurality of light emitting diodes. An exemplary apparatus comprises a first power converter stage, a second power converter stage, a plurality of sensors such as first and second sensors, and a controller. The first power converter stage includes a power switch and a first inductor having a first inductance. The first and second sensors are both coupled to a common reference node, with the first sensor adapted to sense a first parameter of the first power converter stage, and the second sensor adapted to sense the output current level. The second power converter stage includes a second inductor having a second inductance, and is couplable to provide an output current to the nonlinear load such as LEDs. The controller is coupled to the power switch, the first sensor and the second sensor, and the controller is adapted to turn the power switch into an on state for an on-time duration substantially proportional to a ratio of the second inductance to the first inductance.