AN LED DRIVER CIRCUIT, AND LED ARRANGEMENT AND A DRIVING METHOD

摘要

The invention provides a driver circuit for driving an LED arrangement comprising a rectifier and an inductive switched mode down converter which provides an output between first and second output terminals. A buffer capacitor is connected between the first and second output terminals, and a storage capacitor in a series connection with the first output terminal, the second output terminals and a ground line and is charged in series with the LED arrangement (LED1) by the rectified signal. This storage capacitor is thus at the output of the driver circuit, but not in parallel with the output load. Instead, it is in series with the output load. The storage capacitor (C5) is further coupled to and discharge on the DC line so as to power the switched mode down converter when the rectifier bridge is not conducting. It enables a high power factor to be maintained while also enabling low current ripple on the LED arrangement.