Active capacitor circuit

摘要

The present invention relates to an active capacitor circuit (40) for use in a driver device for driving a load (22), in particular an LED unit comprising one or more LEDs (23). Further, the present invention relates to a driver device comprising such an active capacitor circuit. The proposed active capacitor circuit comprises coupling terminals (41, 42) for providing a drive voltage (vD) and/or drive current (iD) for driving a load (22) to be coupled between said coupling terminals (41, 42), an output power stage (50) coupled between said coupling terminals (41, 42) for converting said periodic current (iA) into said drive current (iD), a low frequency capacitor (46) coupled between a capacitor output terminal (48) of said output power stage (50) and a coupling terminal (42), and a control unit (60) for controlling said output power stage (50) by use of a control signal (Sd) obtained from a feedback of the drive voltage (vD), a capacitor voltage (vC) across said low frequency capacitor (46) and/or a capacitor current (iC) through said low frequency capacitor (46).

主权项

1. An active capacitor circuit for use in a driver device for driving a load, the load comprising an LED unit comprising one or more LEDs, said active capacitor circuit comprising:
coupling terminals for providing a drive voltage and a drive current for driving the load to be coupled between said coupling terminals, an output power stage coupled between said coupling terminals for converting a periodic current into said drive current, a low frequency capacitor coupled between a capacitor output terminal of said output power stage and the coupling terminal, and a control unit for controlling said output power stage by use of a control signal obtained from a feedback of the drive voltage and/or a capacitor voltage across said low frequency capacitor, and a capacitor current through said low frequency capacitor,wherein said control unit comprises a first feedback loop for controlling said capacitor current to follow a reference capacitor current.